upper lachlan groundwater flow model · 2018. 4. 23. · figure 2-5 residual mass curve of rainfall...

Leading policy and reform in sustainable water management

Upper Lachlan Groundwater Flow Model

Publisher

NSW Department of Primary Industries, Office of Water.

Level 18, 227 Elizabeth Street GPO Box 3889 Sydney NSW 2001

T 02 8281 7777 F 02 8281 7799

[email protected]

www.water.nsw.gov.au

The NSW Office of Water manages the policy and regulatory frameworks for the state’s surface water and groundwater resources, to provide a secure and sustainable water supply for all users. It also supports water utilities in the provision of water and sewerage services throughout New South Wales.


February 2012

ISBN 978 0 7313 3503 9

This publication may be cited as:

Bilge, H., (2012), Upper Lachlan Groundwater Flow Model, NSW Office of Water, Sydney

© State of New South Wales through the Department of Trade and Investment, Regional Infrastructure and Services, 2012

This material may be reproduced in whole or in part for educational and non-commercial use, providing the meaning is unchanged and its source, publisher and authorship are clearly and correctly acknowledged.

Disclaimer: While every reasonable effort has been made to ensure that this document is correct at the time of publication, the State of New South Wales, its agents and employees, disclaim any and all liability to any person in respect of anything or the consequences of anything done or omitted to be done in reliance upon the whole or any part of this document.

NOW 11_281

Funding for this project has been provided by a National Water Commission grant to the NSW Office of Water under the Raising National Water Standards Program


Contents

Abstract.................................................................................................................................................. iv

1. Introduction.................................................................................................................................... 1

2. Description of the model area ....................................................................................................... 2

2.1 Rainfall and evaporation ..................................................................................................... 4

2.1.1 Rainfall .................................................................................................................... 4

2.1.2 Evaporation............................................................................................................. 8

2.2 Geology............................................................................................................................... 8

2.3 Hydrogeology ...................................................................................................................... 9

2.4 Surface water .................................................................................................................... 11

2.5 Groundwater usage .......................................................................................................... 12

3. Model development ..................................................................................................................... 14

3.1 Conceptual model ............................................................................................................. 14

3.2 Model discretisation .......................................................................................................... 16

3.3 Initial heads ....................................................................................................................... 18

3.4 Aquifer parameters............................................................................................................ 18

3.5 Boundary conditions ......................................................................................................... 20

3.6 Well package..................................................................................................................... 20

3.7 Recharge........................................................................................................................... 21

3.7.1 Rainfall Recharge ................................................................................................. 21

3.7.2 Irrigation Recharge ............................................................................................... 22

3.7.3 Flood Recharge .................................................................................................... 23

3.8 River aquifer interaction .................................................................................................... 25

3.9 Evaporation ....................................................................................................................... 28

3.10 Solver 28

4. Model calibration ......................................................................................................................... 29

4.1 Automatic calibration......................................................................................................... 29

4.2 Final estimates of aquifer parameters .............................................................................. 31

4.3 Head response.................................................................................................................. 39

4.4 Calibration assesment ...................................................................................................... 39

4.5 Sensitivity analysis............................................................................................................ 44

4.6 Water balance................................................................................................................... 46

5. Scenario runs .............................................................................................................................. 48

5.1 Scenario water balance .................................................................................................... 48

i| NSW Office of Water, February 2012


6. Conclusions and recommendations ............................................................................................ 56

7. References .................................................................................................................................. 58

APPENDIX 1: Model geometry ........................................................................................................... 59

APPENDIX 2: Initial head .................................................................................................................. 63

APPENDIX 3: Production bore locations............................................................................................. 66

Table List of Usage Bores ................................................................................................................ 66

APPENDIX 4: River details.................................................................................................................. 67

APPENDIX 5: Monitoring bore locations and model layer boundaries ............................................... 69

APPENDIX 6: Observed and simulated water level hydrographs....................................................... 72

Tables

Table 3-1 Model Grid Specifications ............................................................................................... 16

Table 3-2 Model Time-Discretisation Parameters........................................................................... 16

Table 3-3 Parameter settings in GMG solver package ................................................................... 28

Table 4-1 Model Parameters........................................................................................................... 30

Table 4-2 Calibrated Model Parameters. ........................................................................................ 38

Figures

Figure 2-1 Location of the Upper Lachlan Valley .................................................................................. 3

Figure 2-2 Rainfall stations and contours of average annual rainfall (1986-2008) in the model area .. 4

Figure 2-3 Average monthly Rainfall (mm) registered by eight Meteorological Stations in the model area .................................................................................................................. 5

Figure 2-4 Residual Mass Curve of Rainfall for the period in the model area1889-2007 ..................... 6

Figure 2-5 Residual Mass Curve of Rainfall (65016) against water levels in monitoring bores of 36064_1, 36085_1, 36086_1, 36552_1 and 26554_1.................................................. 7

Figure 2-6 Monthly average evaporation data between 1986 and 2008............................................... 8

Figure 2-7 Location of model cross-sections................................................................................... 9

Figure 2-8 Cross section of the model area ........................................................................................ 10

Figure 2-9 The rivers and creeks in the model area ........................................................................... 11

Figure 2-10 Groundwater usage pattern for each water year in the Upper Lachlan GWMA (1986-2008)..................................................................................................................... 12

Figure 2-11 Groundwater usage bores in the model area .................................................................. 13

Figure 3-1 Conceptual Model .............................................................................................................. 15

Figure 3-2 Conceptual Model – Plan View.......................................................................................... 15

Figure 3-3 Grid details ......................................................................................................................... 17

ii| NSW Office of Water, February 2012


Figure 3-4 Definition of Vertical Leakance Parameter (VCONT) (from Chiang & Kinzelbach, 1996) . 19

Figure 3-5 Assumed monthly pumping and irrigation schedule ....................................................... 20

Figure 3-6 Rainfall Recharge & Evaporation Distribution................................................................. 21

Figure 3-7 Irrigation recharge areas.................................................................................................... 22

Figure 3-8 Assumed yearly irrigation recharge rates .......................................................................... 23

Figure 3-9 Flood recharge areas......................................................................................................... 24

Figure 3-10 MODFLOW conceptualisation of river/aquifer interaction ............................................... 26

Figure 3-11 Schematic diagram of the river sections and gauging stations ....................................... 27

Figure 4-1 Location of pilot points in the Lower Cowra Formation...................................................... 31

Figure 4-2 Hydraulic Conductivity (m/d) distributions in Upper Cowra (Layer 1) ................................ 33

Figure 4-3 Hydraulic Conductivity (m/d) distributions in Lower Cowra (Layer 2) ............................... 33

Figure 4-4 Hydraulic Conductivity (m/d) distributions in Lachlan Formation....................................... 34

Figure 4-5 Specific yield distributions in Upper Cowra........................................................................ 34

Figure 4-6 Storage Coefficient in Lower Cowra .................................................................................. 35

Figure 4-7 Storage Coefficient in Lachlan Formation......................................................................... 35

Figure 4-8 Vertical Leakance (1/d) between Upper and Lower Cowra ............................................... 36

Figure 4-9 Leakance (1/d) between Lower Cowra and Lachlan Formation ........................................ 36

Figure 4-10 Calibrated River Conductance in m2/d/km. ..................................................................... 37

Figure 4-11 Layer 1 Scattergram of modelled versus measured heads and statistics results. ......... 40



Figure 4-14 All Layers calibration assessment: scattergram of modelled versus measured heads, statistics and distribution of residuals results...................................................... 43

Figure 4-15 Adjustable Model Parameter Sensitivities ...................................................................... 45

Figure 4-16 Model Water Balance Summary for July 1986 to June 2008 ......................................... 46

Figure 4-17 Average Annual water balance for individual layers for July 1986 to June 2008 .......... 47

Figure 5-1 Average Annual water balance over dry scenario run June 2008 to July 2108 ................ 50

Figure 5-2 Average Annual water balance over medium scenario run June 2008 to July 2108......... 51

Figure 5-3 Average Annual water balance over wet scenario run June 2008 to July 2108............... 52

Figure 5-4 Dry Scenario yearly groundwater extractions over the 100 year simulation .................... 53

Figure 5-5 Med Scenario yearly groundwater extractions over the 100 year simulation .................... 53

Figure 5-6 Wet Scenario yearly groundwater extractions over the 100 year simulation.................... 54

Figure 5-7 Dry Scenario yearly net river leakage over the 100 year simulation ................................. 54

Figure 5-8 Mid Scenario yearly net river leakage over the 100 year simulation ................................. 55

Figure 5-9 Wet Scenario yearly net river leakage over the 100 year simulation................................. 55

iii| NSW Office of Water, February 2012


iv| NSW Office of Water, February 2012

Abstract The model area is located in the central west of New South Wales. It comprises alluvial deposits

along the Lachlan River from 20 km upstream of Cowra to Lake Cargelligo. The alluvium is commonly known as the Upper Lachlan groundwater source, (designated GWMA 011) for management purposes.

Most of the early groundwater extraction in the Upper Lachlan alluvium was limited to stock and domestic use and town water supply and most irrigation needs were met by surface water. With the reduction in river water supply for irrigation, the potential of groundwater in the Upper Lachlan as an

alternative resource was recognised in the mid 1990s to late.

A groundwater flow model was developed for the Upper Lachlan alluvial aquifers to assist the community and resource managers to develop long term strategies to ensure environmentally

responsible and economically sustainable use of this valuable natural resource.

The alluvial unconsolidated sediment sequence consists of two formations which are the Cowra and Lachlan Formation. Conceptually, for the purpose of this groundwater flow model the groundwater

system is defined in terms of four layers;

Layer 1- Upper Cowra

Layer 2- Lower Cowra

Layer 3- Lachlan

Layer 4 Fractured Rock (inactive).

An inactive fourth layer has been included in the model to account for the fractured rock aquifer which

is in direct contact with the overlying sediments. In time, this layer may be activated if there is evidence to suggest any significant interaction between the alluvial and fractured rock aquifers should this prove to be a significant of water.

The model calibration period is from July 1986 to June 2008. Recharge components to the aquifers are from rainfall, rivers, flood and irrigation. Discharge is predominantly through evapotranspiration, groundwater extraction and river leakage. Groundwater outflow occurs across the western boundary

and there is no inflow from any of the boundaries. The direction of regional groundwater movement is generally from east to west.

Non linear parameter estimation (PEST) was used to aid calibration of the model based on observed

water levels from NOW monitoring bores. Based on comparison between observed and simulated groundwater levels for the entire calibration period, the model achieved a good match with measured data in general with the exception of Zone 7. Low SRMS (scaled root mean square) values (less than

5%) were achieved for all three layers - confirming that the model is well calibrated overall. Poor calibration of bores in Zone 7 is attributed to the lack of shallow water table monitoring bores in the area.

The annual average total recharge is 186.48 GL from all recharge sources in the calibration period. The average rainfall recharge is about 59% of the total recharge. The total annual average discharge is 156.30 GL. The evapotranspiration is about 76% of this total while groundwater extraction makes up

11%. Evaporation is the dominant component of outflow over the calibration period.

“Dry”, “medium” and “wet” climate scenarios were formulated to examine the aquifer behaviour under “no pumping”, “current development” and “full entitlements” conditions. These scenarios showed that if

there was no pumping in the region, water level would rise causing river leakage to decrease and evapotranspiration to increase. If there were high pumping, water levels would have declined causing evapotranspiration to decrease and river leakage to increase.


1. Introduction

The Upper Lachlan Valley is located in central western New South Wales. For groundwater

management purposes this area is referred to as Groundwater Management Area (GWMA) 011. The area stretches from Lake Cargelligo in the west to 20 km east of Cowra. The groundwater system provides water for stock and domestic, irrigation, town water supply and industry in the region.

Within the Upper Lachlan Valley groundwater source there are two geological formations, which are the deeper Lachlan Formation and the shallower Cowra Formation. The Cowra Formation has separated into two distinct aquifers; layer 1- the shallower unconfined water table Upper Cowra aquifer

and layer 2- deeper semi confined to confined Lower Cowra aquifer. Layer 3- the Lachlan Formation which has a maximum thickness of around 90 m. The Cowra Formation is generally 30-50 m thick in most areas. However, it can reach greater depths up to about 110 m in the south.

The GWMA 011 is embargoed for new groundwater entitlements. The current total entitlement is 184,575 ML/y. Groundwater extraction has risen in recent years from 18,700 ML in 2001/2002 to 84,600 ML in 2007/2008.

Conceptually, the groundwater system is divided into four major regional aquifers: an upper Cowra, a lower Cowra, a deeper Lachlan and fractured rock. There is no hydrogeological distinction between the Upper and Lower Cowra formation layers included in the model. For modelling purposes, an

arbitrary thickness of Upper Cowra 20 m maximum in the centre of the valley was assumed. Fractured rock layer is an inactive layer.

Recharge mechanisms to the aquifer include rainfall recharge, river leakage, flood recharge and

irrigation recharge. Discharges from the system are through evapotranspiration and groundwater pumping from all aquifers. The aquifer system receives no lateral flow through boundaries in the north, south and east. Groundwater flow out of the system is westward into the Lower Lachlan valley.

Regional flow is from east to west.

A modular groundwater flow model (MODFLOW), using a non-uniform finite difference grid, was adopted for this study. Square cell dimensions vary from 500 m in the vicinity of the Lachlan River,

and increase progressively to 2000 m away from the river to the north and south. The model grid is rotated 20 degrees anti clockwise. Grid size and rotation were selected to ensure an acceptable degree of detail along the river tract to provide better understanding of stream-aquifer interaction. The

area covers approximately 50,960 km2. The starting and ending model calibration period are July 1986 and June 2008 respectively. These dates were selected to include drought and flood conditions in the calibration simulation.

The groundwater flow model for the Upper Lachlan Valley was developed to:

Aid understanding of the flow system

Identify key recharge sources and quantify the contribution from each source

Identify parts of the aquifer under stress

Identify parts of the aquifer with development potential

Aid assessment of the impact of groundwater development on river flow

Aid understanding of the processes of river/aquifer water interchange

Estimate recharge to the groundwater system

Evaluate the impact of climate change on groundwater availability.

This report outlines the hydrogeology of the model area and development of the groundwater flow model.

1| NSW Office of Water, February 2012



2. Description of the model area

The extent of the Upper Lachlan Valley groundwater model area is shown in Figure 2-1. The model

extent is defined by AMG coordinates 408000-666000 m E and 6160000-6370000 m N.

The major water courses in the study area includes the Lachlan River which flows from east to west, the lower end of the Belubula River and Mandagery Creek in the north-east, the lower end of Goobank

Creek in the north and Crowther Creek in the south-east. Cowra, Forbes and Parkes are the main urban settlements located in the model area. Other towns in the area include Canowindra, Condobolin and West Wyalong.

The Newell Highway runs in the north-south direction in the central part of the model area.

The GWMA 011 has an area of 13087 km2 and for management purposes the area is divided into eight zones:

Zone 1 - Back Creek Cowra,

Zone 2 - North of the Western Hwy Cowra to Gooloogong,

Zone 3 - Gooloogong to Jemalong Gap,

Zone 4 - Mandagery Creek,

Zone 5 - Jemalong Gap to Condobolin,

Zone 6 - South of the Western Hwy Cowra,

Zone 7 - Bland Creek System

Zone 8 - Condobolin to Lake Cargelligo


Figure 2-1 Location of the Upper Lachlan Valley



2.1 Rainfall and evaporation

2.1.1 Rainfall

Daily rainfall in the study area has been recorded at a number of weather stations at variable intervals. Rainfall records from eight stations monitored by the Australian Bureau of Meteorology were examined

for the purpose of model construction. These stations (65091, 73014, 65016, 65026, 73037, 50044, 50014 and 75039) are shown in Figure 2-2 together with contours of average annual rainfall for the period 1986-2008.

Figure 2-2 Rainfall stations and contours of average annual rainfall (1986-2008) in the model area

450000 500000 550000 600000 650000

6200000

6250000

6300000

6350000

Forbes

Parkes

CowraGrenfell

Condobolin

West Wyalong

Temora

Lake Cargelligo#65016

#65026

#65091#73014

#50014

#50044

#73037

#75039

Rainfall in the Upper Lachlan Valley generally decreases with decreasing elevation towards the west. Contours of mean annual rainfall in Figure 2-2 show the high rainfall contour (620 mm/year) lies along the eastern margins of the basin. Average annual rainfall, for the same period, ranges from 421 mm at

Lake Cargelligo to 619 mm at Grenfell, a difference of 198 mm a year over a distance of 258 km.



The average monthly rainfall for the study area is given in Figure 2.3 Over 35 percent of the annual rainfall at Forbes occurs between June and September. July with average rainfalls of approximately 47 mm is the wettest months. March and May are the driest months with the average rainfall around

37 mm respectively.

Figure 2-3 Average monthly Rainfall (mm) registered by eight Meteorological Stations in the model area

Average Monthly Rainfall

0

10

20

30

40

50

60

70

1 2 3 4 5 6 7 8 9 10 11 12

Months

Ave

rag

e R

ain

fall

mm

Cowra

Grenfell

Forbes

Parkes

Temora

West Wyalong

Condobolin

LakeCargelligo

The cumulative residual-mass curve in Figure 2-4 provides a good visual representation of the rainfall history. The residual mass curve is calculated by subtracting the mean monthly rainfall for a given month from the recorded rainfall for the same month, and adding the difference to a rolling sum. A

falling trend indicates a period of lower than average rainfall, whereas the reverse is true for rising trends. From 1908 to 1946, the rainfall was below average; and this is considered a dry period. From early 1947 to early 1965, the annual rainfall increased markedly to a record high. Between 1965 and

1968 shows a drop in average rainfall and a rise during the next ten years which indicates higher than average rainfall.

Changes in the residual mass curve can be compared with changes in bore water levels to examine

links between long-term rainfall trends and fluctuations of groundwater level. Figure 2-5 demonstrates that there is a strong relationship between the rainfall residual mass curve and fluctuations of water table in the model area.

Summer mean maximum temperatures are greater than 30oC in most areas. In winter, minimum temperatures of less than 3oC are common.



Figure 2-4 Residual Mass Curve of Rainfall for the period in the model area1889-2007

Residual Mass Curve

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as

s (

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)

Cowra

Grenfell

Forbes

Parkes

Temora

West Wyalong

Condobolin

Lake Cargelligo



36084, 36085, 36086, 36552 &36554 v FORBES 65016 Station

-200

0

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71

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th

Forbes_65016

GW036084_1

GW036085_1

GW036086_1

GW036552_1

GW036554_1

Figure 2-5 Residual Mass Curve of Rainfall (65016) against water levels in monitoring bores of 36064_1, 36085_1, 36086_1, 36552_1 and 26554_1



2.1.2 Evaporation

The weather stations providing rainfall data for the model also provided evaporation data. The average monthly evaporation data for these stations are shown in Figure 2-6. The average annual evaporation is between from 1534 to 2014mm (1986-2008). Highest monthly evaporation occurs in December and

January in response to high the summer temperatures. Lowest monthly evaporation occurs in June and July.

Figure 2-6 Monthly average evaporation data between 1986 and 2008

Monthly Evaporation

0

50

100

150

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250

300

350

1 2 3 4 5 6 7 8 9 10 11 12

Months

mm

Cowra

Grenfell

Forbes

Parkes

Temora

Westwyalong

Condobolin

LakeCargelligo

2.2 Geology

The regional geology of the area has been studied by Gates and Williams (1988), Bish and Gates (1991) and Muller and Lennox (1999). The following description is reproduced from the latter

reference.

“It can be seen that much of the central part of the area is covered by unconsolidated alluvial and colluvial sediments. With the exception of some coarse-grained Jurassic sediment in the north and

the Carboniferous granites to the east, most rock types were formed prior to the Carboniferous period (354 million years ago). Ordovician metasediments are extensive throughout the area as are Silurian-Devonian granites and granodiorites. Volcanic rocks are extensive in the east and in

many cases are comagmatic with adjacent plutonic rocks. These igneous rocks have been major source of material for the sedimentary rocks of the region. Depositional environment for sedimentary rocks would have been dominantly marine or marginal for rocks of early Devonian

age or older. Transitional and freshwater environments existed after this time. Structurally, the area is quite complex with several orogenic episodes deforming and displacing the strata between the Ordovician and Carboniferous periods. This activity was associated with the formation of the

Lachlan Fold Belt. After this time, conditions in the study area stabilised and erosional processes dominated until the advent of the Cainozoic, when both erosional and depositional processes formed the present day landscapes”.



2.3 Hydrogeology

The alluvial unconsolidated sediment sequence is divided into two major aquifer formations, the Cowra Formation and the deeper Lachlan Formation. The Cowra Formation unconformably overlies

the Lachlan Formation and basement rocks. It is generally 30-50 m thick in most areas. However it can reach greater thickness - up to about 110 m - in Zone 7. It consists mainly of clay with interbedded moderately sorted sand and gravel. The Cowra Formation is divided into two aquifers in

the model area, the Upper Cowra unconfined water table aquifer and the Lower Cowra semi confined to unconfined aquifer. The Lachlan Formation occurs in the deep incised palaeo channel of the Lachlan River and the maximum thickness is around 90 m. This Formation consists of subrounded to

rounded, grey to off white sand and gravel with larger amounts of interbedded brown to yellow to grey clay. Representative cross sections for lines depicted in Figure 2-7 are presented in Figure 2-8. The fractured rock (layer 4) shown with a minimal thickness that does not represent reality.

The water quality in the Cowra formation deteriorates with distance from the Lachlan River and its tributaries as discussed by O’Rourke (2007)

Figure 2-7 Location of model cross-sections

450000 500000 550000 600000 650000

6180000

6200000

6220000

6240000

6260000

6280000

6300000

6320000

6340000

6360000

Forbes

Parkes

CowraGrenfell

Condobolin

West Wyalong

Temora

Lake Cargelligo

A

A

B

B

C

C

D

D



Figure 2-8 Cross section of the model area



2.4 Surface water

The Lachlan River is one of the major recharge sources in the Upper Lachlan GWMA. The Lachlan River directly overlies the alluvial aquifers. Interaction between the Lachlan River and the aquifer

system is known to have an important influence on groundwater levels within the model area. The Lachlan and Belubula Rivers are regulated from water stored in Wyangala and Carcoar Dams respectively. Minor unregulated tributaries include Back Creek, Mandagery Creek, Island Creek,

Ulgutherie Creek and Goobank Creek in the study area. The Lachlan River and its branches in GWMA 011 are shown in Figure 2.9.

Figure 2-9 The rivers and creeks in the model area

380000 400000 420000 440000 460000 480000 500000 520000 540000 560000 580000 600000 620000 640000 660000 680000

6120000

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6280000

6300000

6320000

6340000

6360000

6380000

6400000

Forbes

Parkes

CowraGrenfell

Condobolin

West Wyalong

Temora

Lake Cargelligo



2.5 Groundwater usage

Groundwater from the alluvium of the Upper Lachlan Valley is used extensively for irrigation, town and rural community water supplies and stock and domestic requirements. Most high yield bores are used

for irrigation and town water supply. The volume of groundwater extraction from the Upper Lachlan GWMA for the water years 1986–2008 is shown in Figure 2-10.

Figure 2-10 Groundwater usage pattern for each water year in the Upper Lachlan GWMA (1986-2008)

Yearly GW Usage Volume

1078

1349

1035

1167

1822

1465

461

473 36

37

4194

4088

5641

7595

9747 1247

1

1876

1

4539

5

5143

9

6580

3

5705

9

8461

7

7648

9

0

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60000

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90000

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-87

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-94

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-95

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-01

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-03

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-05

2005

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2006

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2007

-08

Water Year

ML

There is little available data for usage prior to 1998. However this has little impact on the model development since data are available for the major part of the calibration period (July 1986 to June

2008). Reliable metered groundwater usage data are available in NOW databases from 1998/1999 to the present. There has been a considerable increase in groundwater usage volumes and the area irrigated by groundwater since 1994 since the implementation of the Murray Basin surface water cap.

As a consequence of this measure, groundwater use partially replaced the use of surface water. The locations of the currently 388 active groundwater pumping wells are presented in Figure 2-11.



Figure 2-11 Groundwater usage bores in the model area

450000 500000 550000 600000 650000

6180000

6200000

6220000

6240000

6260000

6280000

6300000

6320000

6340000

6360000

Forbes

Parkes

CowraGrenfell

Condobolin

West Wyalong

Temora

Lake Cargelligo



3. Model development

A numerical groundwater model is a computer-based mathematical representation of a natural

hydrogeological system that is based on a conceptual model of that system. The mathematical model is a set of equations which, subject to certain assumptions and boundary conditions, describes the essential physical features and processes of the groundwater system. The set of equations is solved

using numerical methods (e.g. finite differences).

The numerical model is developed with MODFLOW 2000 finite difference software (McDonald & Harbaugh, 1988), using the Groundwater VistasTM (Version 5.41) graphical user interface in a

Windows environment.

Nine MODFLOW packages are used in this model:

Basic (BAS) package,

Block Centred Flow (BCF) package,

Discretization (DIS) package

Constant Head Boundary (CHD) package,

Recharge (RCH) package,

Well (WEL) package,

Evapotranspiration (EVT) package

River (RIV) package,

Pre-conditioned Conjugate Gradient (GMG) package.

This chapter describes the data analysis and processing required to develop the model under the

MODFLOW framework.

3.1 Conceptual model

A conceptual model is a simplified presentation of the groundwater flow system including major hydrostratigraphic units and boundary conditions. Such a conceptual model for the Upper Lachlan groundwater model is illustrated in Figure 3-1.

Conceptually, the groundwater system is defined in terms of four layers, designated Upper Cowra, Lower Cowra, Lachlan and fractured rock.

The Upper Cowra (layer 1) in the upper alluvium is an unconfined aquifer and its thickness has a fixed

maximum value of 20 m if the total thickness of the Cowra (Upper and Lower) Formation exceeds 40 m. The Lower Cowra (layer 2) in the lower alluvium of the Cowra Formation is an unconfined/confined aquifer. The Lachlan Formation aquifer (layer 3) in the deep alluvium is also

conceptualised as unconfined /confined. Layer 4 is an inactive fractured rock layer included in the model to facilitate future modifications should data become available to indicate hydraulic connection with the overlying alluvial aquifers.

The system is assumed to be enclosed by impermeable basement.

The western boundary is a flow boundary where either groundwater potential or flow-rates can be prescribed as a function of time and position. Significant fluxes of groundwater across this boundary

(shown in Figure 3-2) are expected due to connectivity with adjoining aquifers. The boundaries to the east, north and south are treated as no-flow boundaries

The major recharge sources of the aquifers are identified as rainfall, irrigation, floods and the river

system comprising the Lachlan River, Belubula River, Mandagery Creek, Goobank Creek, Back Creek, Island Creek and Ulgutherie Creek. Discharge from the aquifer is mainly due to evapotranspiration, groundwater extraction and outflow through the western boundary.



Figure 3-1 Conceptual Model

Figure 3-2 Conceptual Model – Plan View

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3.2 Model discretisation

Use of MODFLOW software requires discretisation of the model spatially as well as temporally. Spatial discretisation is achieved by specifying an orthogonal set of rows and columns to form a mesh over

the model area. While a regular mesh with uniform row and column widths yields the most accurate form of the finite difference solution, often it becomes necessary to refine the mesh in key areas of interest. In the current grid, row widths are appropriately sized to ensure an acceptable degree of

detail along the river tract to provide a better understanding of stream-aquifer interaction. In order to produce a numerically efficient model, the grid is rotated 20 degrees anticlockwise (Figure 3-3) relative to the Australian Map Grid (AMG) to minimise its overall size. The grid cells falling outside the model

boundaries and outcrop areas are designated as inactive. Data pertaining to the model grid are summarised in Table 3-1.

The model calibration period is from July 1986 to June 2008. According to the rainfall residual mass

curves presented in Chapter 2 (Figure 2-4), this start date appears to be within a period of relatively stable climatic conditions. In addition, over this period, a significant set of observed water level data are available within the model area, for meaningful comparison with corresponding model predictions.

Transient simulation of a MODFLOW numerical model needs the calibration period to be discretised into several stress periods. Stress periods are periods within which the various model stresses are assumed to remain constant and for which data are available or can reasonably be inferred. The

model computes the groundwater elevation at the centre of each active grid cell in the model space, at each stress period during simulation. MODFLOW's approach to solving the mathematics of groundwater flow also requires that stress periods be further discretised into a number of time steps

using a suitable time step multiplier. Time discretisation parameters are summarised in Table 3-2.

Table 3-1 Model Grid Specifications

South-west corner easting, northing: 378 000, 6 237 000m AMG

Angle of rotation relative to AMG: 20 degrees (anticlockwise)

No. of layers 4

No. of columns: 535

No. of rows: 192

Column width 500 m

Row width (varied) 500 - 2000 m

Total Cells (active + inactive): 410880

Table 3-2 Model Time-Discretisation Parameters

Stress period length: 1 month (30.44 days)

No. of stress periods: 264

No. of Time steps 10 (in each stress period)

Time step multiplier 1.2

Start of calibration period: July 1986

End of calibration period: June, 2008

Calibration period length: 22 years


Figure 3-3 Grid details

20 deg



The following five surface elevation data sets are required to be specified in m AHD, for each active cell in the current model to define aquifer geometry.

Natural surface (which is also the top of the Upper Cowra Formation)

Bottom of Upper Cowra Formation (which is also the top of the Lower Cowra Formation)

Bottom of Lower Cowra Formation (which is also the top of the Lachlan Formation)

Bottom of Lachlan Formation (which is the hydraulic basement as well as the top of the Fractured Rock) while layer 4 is inactive

Hydraulic basement bed surface (which is also the bottom of the fractured rock)

Topographic DEM data were used to define the natural surface elevation of the model. Data for the

elevations of the four remaining surfaces were obtained from several sources which included Murray Basin Hydrogeological Map Series CARGELLIGO scale 1:250 000, Barnett (2008), SKM Upper Lachlan Groundwater Model Calibration Report and Coffey Geosciences Pty Ltd Cowal Gold Mine

Groundwater supply modelling study (2006). SurferTM software was used to create all five layer elevations using available data before importing into the model. Contour maps showing the three model layer thicknesses are presented in Appendix 1.

3.3 Initial heads

The MODFLOW numerical model requires the specification of head for every active cell in each layer

at the start of the calibration period. Transient models require initial conditions closely matching natural conditions at the start of the simulation. The initial conditions are the heads from which the model estimates the changes in the system due to the stresses applied. Therefore, any errors

associated with assumptions made to obtain such data are likely to impact overall model performance.

Water-level data for each piezometer at the first sampling date on or after 1st July 1986 were extracted from the NOW’s Groundwater Data System (GDS) for observation bores in the study area.

Water-level data were manually inspected to remove ‘bad’ or ‘suspect’ values, then the initial heads of all layers specified in the model were obtained using SURFERTM software. This process caused some cells at the margins of layers 1 and 2 to start as dry (that is, the interpolated heads were below the

layer base), because there are fewer observation bores near the lateral boundaries of the model area and layers 1 and 2 generally rise in elevation towards these boundaries. The starting heads in these cells were therefore specified as a nominal height above the bottom of layer 1. The resulting SURFER

‘grid’ files were imported directly into Groundwater Vistas for analysis. The starting heads contours are graphically displayed in Appendix 2.

3.4 Aquifer parameters

Transient numerical models require knowledge of hydraulic conductivity and storage capacity of the aquifer medium in each cell to compute the flow between adjacent cells and the rate of movement of water to and from storage. Usually, the parameters such as hydraulic conductivity and storativity of

material forming the aquifer vary across the model area laterally as well as vertically. Aquifer parameters are generally estimated from pumping tests.

Following pumping test analysis, Anderson (1993) suggested ranges of aquifer transmissivity for the

depth range 24.4 to 60 m. Transmissivity varied from 49 to 1200 m2/d around the Jemalong and Wyldes Plains Irrigation Districts. There is no trend evident either spatially, or with depth. Several NOW irrigation bores have been pump tested. Bore 25165, of the Mulguthrie Section, was pump

tested at a depth of 60.9-70 m, giving rise to a transmissivity of 71 m2/d. Similarly, bores 36551 and



36523 of the Corinella section were pump tested. For bore 36551, the aquifer tested was at a depth of 60.47-63.76 m and the transmissivity value determined was 780 m2/d. The zone tested in bore 36523 was a much deeper Lachlan Formation aquifer (119.6-122.6 m) and transmissivity was found to be

1160 m2/d.

Megalla and Kalf, (1973) recommended specific yield value of 0.10 for the alluvials in the region and Coffey (2006) used a value of 0.04.

Based on the calibrated aquifer parameters, Coffey (2006) estimated hydraulic conductivity to be in range 3 - 28 m/d for the Lachlan Formation and 1 m/d for the Cowra Formation. They estimated vertical leakance between the Cowra and Lachlan Formation to be 5.3x10-7 d-1.

Barnett and Muller (2008) used calibrated hydraulic conductivity values from 1 to 10 m/d for the Upper and Lower Cowra Formation and between 10 and 100 m/d for the Lachlan Formation.

These values were used to identify upper and lower hydraulic property bounds and initial estimates for

the model. Some values were changed to obtain a better calibration during the calibration process.

Specification of hydraulic conductivity (in X- and Y- directions) and storage factors (specific yield and storage coefficient) for each zone is needed in Groundwater Vistas. For the Upper Cowra Formation,

which is unconfined, specific yield is used in MODFLOW computations. For the Lower Cowra and Lachlan aquifer, which are designated as 'confined/unconfined', both specific yield and storage coefficient are needed. As long as the aquifer remains confined during simulation, the assigned

specific yield values have no impact on the model. If it becomes unconfined at any stage during simulation, then MODFLOW uses specific yield in place of storage coefficient in computations.

For a model consisting of more than one layer a vertical conductance term, known as vertical

leakance (VCONT) is also required for all but the lower most layer. This parameter represents the leakage occurring between two model layers and is defined in terms of layer thicknesses and vertical hydraulic conductivities as shown in Figure 3-4.

In Groundwater Vistas, the user has the option either to specify vertical leakance for each parameter zone or to allow MODFLOW to compute vertical leakance based on the above relationship. However, the latter will require specification of the hydraulic conductivity in the vertical direction in each zone.

Aquifer parameters together with layer elevations are written into the block-centred-flow (BCF) package in MODFLOW.

Figure 3-4 Definition of Vertical Leakance Parameter (VCONT) (from Chiang & Kinzelbach, 1996)



3.5 Boundary conditions

Boundary conditions determine where water enters or leaves the model domain and in what quantity. Commonly three different boundary conditions are identified in groundwater modelling. They are

specified head, specified flow and mixed type (head dependent) boundaries. The discussion in this section is limited to the relationships between the spatial boundaries of model flow domain and the external environment.

Model boundaries in the east, north and south are specified as 'no-flow' which means that no groundwater flow occurs across these boundaries. The western boundary is designated as a 'constant head boundary (CHD) in which the head varied with time.

3.6 Well package

The well package is designed to represent extraction of water from cells and to account for such

losses in the finite difference equations. Recharging and discharging wells have positive and negative rates respectively. For each cell in each layer, only one value for net discharge can be specified for a given stress period.

This groundwater model simulates monthly stress periods and requires monthly frequency for data. Usage data prior to 1998 were relatively small and unreliable. However, after 1998 reliable annual groundwater usage data is available. In order to simulate pumping in the model it was necessary to

derive monthly usage patterns from the yearly usage data by applying a specified percentage distribution. Assumed pumping schedule is shown in Figure 3-5. However, the actual pattern of usage may vary with the purpose of the bore. For a listing of the bores used in the well package, refer to

Appendix 3.

Figure 3-5 Assumed monthly pumping and irrigation schedule

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The model runs from July 1986 to June 2008; however before 1998 the usage data set is incomplete for the model period. A twelve year gap in usage data at the beginning of the model has implications

for the calibration of the model. If the applied stress from groundwater extraction is not accurate the model may not represent real conditions and may not calibrate properly as discussed in Bilge (2001) and Salotti (1997).



3.7 Recharge

The recharge package adds terms representing distributed recharge to the finite difference equation. In this study, the aquifer is recharged by rainfall, flood, irrigation and stream leakage. Recharge

relative contributions are further explained in section 4.6. All recharge sources may vary spatially as well as temporally. Recharge due to river leakage is considered separately under stream/aquifer interaction as discussed in Section 3.8. The remaining sources rainfall, flood and irrigation, are

simulated in the model using MODFLOW’s recharge package. Recharge is applied to the highest active layer.

3.7.1 Rainfall Recharge

Recharge from rainfall can occur in a number of ways. For example, it can occur through direct

infiltration beyond the root zone. Rainfall induced recharge can occur through side-slope run-off and ephemeral streams which may include lagoons and flood runners. As mentioned in Section 2.1, changes in the residual mass curves developed for the region compare well with changes in bore

water levels in undeveloped areas indicating a strong link between long-term rainfall trends and fluctuations of groundwater level.

A rainfall recharge rate of 2 % and bounds between 0.1 % and 5 % of average annual rainfall were

based on Dawes et al (2000) which provides estimates for medium scale catchments in the Liverpool Ranges of NSW, were used in initial model calibration attempts. These values were subsequently changed to obtain a better model calibration.

The assumed area of influence of each rainfall station based on the Thiessen method is shown in Figure 3-6.

Figure 3-6 Rainfall Recharge & Evaporation Distribution

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3.7.2 Irrigation Recharge

Leakage from crop irrigation systems is a source of artificial recharge to the aquifer system. The irrigation recharge areas within the model are based on the department’s GIS Land Use Classification Mapping in 2000 as shown in Figure 3-7. These areas are assumed to be constant throughout the

calibration period (July 1986 - June 2008) but irrigation recharge rates are varied proportionately based on the historical record of surface water diversion.

The standard irrigation application rate for non-rice crop farmlands is 6 ML/ha/yr. Of this, about 5

ML/ha/yr is assumed to be lost through evaporation. Therefore, only 1ML/ha/yr is available for irrigation recharge. This is equivalent to 100 mm of water per farmland hectare per year which is the maximum irrigation recharge available after irrigation efficiency, crop interception and initial soil

moisture are taken into account Prathapar (pers. comm.).

Figure 3-7 Irrigation recharge areas

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It is reasonable to assume that the component of irrigation recharge returns to the groundwater regime to be between 20 and 40 mm/ha/yr. In the current model surface water use during the calibration period (1986-2008) and spatial irrigated area water year 2000-2001 are available however, the pattern

of spatial growth of irrigated area over the years is not known accurately. Irrigation recharge of 30 mm/ha/yr in the water year 2000-2001 was assumed and the level of recharge for other years was estimated proportionately based on historical records of surface water diversion in each year. These

diversions are shown in Figure 3-8. The monthly irrigation schedule shown in Figure 3-2 was applied to the annual diversions to obtain monthly components of irrigation recharge. While this approach makes sure that the aquifer system received the full complement of irrigation recharge every year, it

fails to replicate accurately any local impacts on the water table due to irrigation practice.



Figure 3-8 Assumed yearly irrigation recharge rates

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3.7.3 Flood Recharge

In the period from July 1986 to June 2008 two flood events occurred within the model area, a major

event occurred in April-August 1990 and a minor event in June-July 1998. For the model, only the major event was taken as a recharge contributor. For this event the area coverage and the model hydrographs response are clearly visible. The inundated area during the 1990 flood is shown in Figure

3-9, based on available GIS flood maps.

The inundated area is divided into eight Thiessen polygons identical to the rainfall zones shown in Figure 3-6 for calibration purposes. Initial flood recharge fluxes for each zone varied from 0.0002 to

0.005 m/d. These values were adjusted during calibration. The period of flood inundation was seven months from May 1990 to November 1990.



Figure 3-9 Flood recharge areas



3.8 River aquifer interaction

Some interaction between streams and the shallow aquifer exists in most alluvial formations. The model indicates the Lachlan River suffers considerable losses to groundwater along its course. It is

likely that increased groundwater pumping in the vicinity of the river in recent years has contributed to some of these losses.

MODFLOW (McDonald and Harbaugh, 1988) simulates leakage between a river and the aquifer as a

vertical flow through the riverbed. The direction of leakage through a river cell depends on the relative positions of the groundwater level (Hijk) and the river stage (HRIV). The rate of leakage (QRIV) is controlled by the head and the conductance (CRIV) of the riverbed within a particular river cell (see

Equation 3.1).

QRIV = CRIV (HRIV – Hijk), for Hijk > RBOT (Equation 3.1)

CRIV = KLW / M

where, K = the conductivity of the riverbed material L = the river reach length W = the river width M = the thickness of riverbed material

If (HRIV – Hijk) < 0, then the seepage is in the direction of the river (a gaining river cell, see Figure 3-10). If (HRIV – Hijk) > 0, then the seepage is in the direction of the aquifer (a loosing river cell, see

Figure 3-10). In both these situations, it is assumed that the head in the aquifer is above the river bottom elevation (RBOT). However, there may be instances where the groundwater level (Hijk) falls below the river bottom. In such a situation, MODFLOW assumes a constant seepage from the river (a

percolating river cell). The rate of flow from the river is solved by Equation 3.2 is independent of further head decline of the aquifer (a percolating river cell as shown in Figure 3-10.

QRIV = CRIV (HRIV – RBOT), for Hijk RBOT (Equation 3.2)

Of the four parameters contributing to CRIV, only the river reach length (L) is known accurately. River width (W), river bed thickness (M) and hydraulic conductivity (K) in each river cell are difficult to estimate with any confidence. Hence, the lumped parameter, KW/M, is assumed initially and adjusted

during the calibration process.

The parameters required in MODFLOW’s river package to simulate stream/aquifer interaction for each designated river cell are the layer number, row and column of the cell, river stage, river bottom

elevation and river conductance. Groundwater VistasTM allows the specification of a reach number as well.



Figure 3-10 MODFLOW conceptualisation of river/aquifer interaction

Gaining river

Loosing river

Percolating river

There are thirteen gauging stations along the stretch of the river considered in this study. Of these, only seven stations have continuous records of river gauging data covering the entire model calibration period. River hydrographs at the seven stations, gauging station and weirs are given in Appendix 4.

The preparation of input data for MODFLOW involves a number of tasks, which are listed below:

Digitising river reach for the Lachlan River and processing river data to obtain river length within a cell.

Extractions of river stage data for each gauging station covering the model calibration period.

Estimation of missing data through interpolation.

Processing riverbed data from available gauging station elevations.

Establishment of hypothetical gauging stations and estimation of river stage data.

Preparation of the surface topography map of the model area on a cell-by-cell basis.

Processing data using a modified version of ‘VMRIVER’ software developed by Demetriou (1995) to create the river boundary file for Visual MODFLOW.

A schematic diagram of the 23 sections and thirteen gauging stations used in the model is presented in Figure 3-11. The river package has a total of 2037 river cells belonging to twenty three sections. River hydrographs and river gauging station and weirs are given in Appendix 4.




Figure 3-11 Schematic diagram of the river sections and gauging stations

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3.9 Evaporation

MODFLOW’s evapotranspiration (EVT) package simulates the effects of plant transpiration and direct evaporation in removing water from the saturated groundwater regime (McDonald & Harbaugh, 1988).

As implemented in MODFLOW, for each model surface cell a maximum rate of evapotranspiration (ET) is specified for each surface cell together with an ET surface elevation and an ‘extinction depth’. When the water table depth is at or above the ET surface, evapotranspiration occurs at the maximum

specified rate. When the water table lies below the extinction depth, zero evapotranspiration occurs. Between these two depths, evapotranspiration varies linearly.

Eight evapotranspiration zones were introduced in the model area, identical to the distribution of

recharge zones presented in Figure 3-6. A starting value of 10% of the potential evaporation (m/d) recorded at weather stations were specified as the initial evapotranspiration rate at the ground surface in all eight zones. The extinction depth was varied from 3 to 9 meters below the surface across the

model area. Evapotranspiration is applied to the highest active layer.

3.10 Solver

The 'Geometric Multigrid (GMG)' is used as the mathematical solver in this model. The parameter settings for the package are shown in Table 3-3.

Table 3-3 Parameter settings in GMG solver package

Maximum Inner Iterations 500

Maximum Outer Iterations 1

Head Change Criterion for Convergence 0.001

Inner Convergence Criterion 0.1

Relaxation Parameter 0

Adaptive Damping Flag 0

Output Control Flag 4

Damping parameter 1.0



4. Model calibration

Calibration of a numerical groundwater flow model can be accomplished by determining a set of

parameters, boundary conditions and stresses that produce simulated heads and fluxes in order to match field-measured values within a pre-established range of error. Finding this set of values from a set of observed heads amounts to solving the inverse problem (Anderson, Gates & Mount, 1993).

During the calibration process, important model parameters are adjusted, within realistic limits, to produce the best match between simulated and observed data. The process begins with an initial estimation of parameters (hydraulic conductivity horizontal and vertical, specific yield, recharge,

boundary conditions, etc.) for each active cell in the model grid. Adjustment of parameters can be done manually or automatically. Automatic calibration method was attempted in the current model.

PEST (Doherty, 2005) is nonlinear parameter estimation software which is used in automatically

calibrating complex groundwater models. PEST was used in “regularisation mode” coupled with “pilot points” as a method of spatial parameterisation to calibrate the current model. A total of 1845 estimable parameters were used. PEST software can automatically adjust model parameters to

minimise the discrepancies between the observed data and model predicted values (residuals). The objective function (phi), defined as the ‘sum of squares of weighted residuals’ is used as a calibration statistic. In a mathematical sense, a lower objective function indicates better model calibration.

The starting and ending times of the model calibration period are 1/7/1986 and 30/06/2008 respectively.

Water level data from observation bores in the model area were utilised to obtain target results for

calibration. Thirty-four observations bores in layer 1, ninety four bores in layer 2 and fifty in layer 3 were used for the model. Their spatial distribution is shown in Appendix 5.

4.1 Automatic calibration

Nonlinear parameter estimation software is commonly used in calibrating complex groundwater models. PEST is one such nonlinear parameter estimator which is powerful and model independent.

PEST was used in "regularisation mode" coupled with "pilot points" as a method of spatial parameterisation to calibrate the current model. SVD-Assist is a powerful new model calibration tool available in PEST which embodies a hybrid regularisation methodology that combines the strengths of

subspace methods, for example singular value decomposition (truncated SVD), and Tikhonov regularisation methodologies.

In the pilot point parameterisation scheme, parameter values are assigned to a set of points

distributed throughout the model domain. These parameter values are then spatially interpolated to the individual cells of the model grid using the spatial interpolation method ‘kriging’. Regularisation across the entire model domain is allowed to take place with ‘preferred parameter’ values included as

‘regularisation observations’ to enforce a smoothing condition. The fundamental purpose of regularisation is to prevent extreme parameter values at pilot points and to produce a smooth parameter distribution.

The number of pilot points used in each layer varied and the parameters estimated are summarised below:

layer 1 hydraulic conductivity (kx1_1 to kx1_164)

layer 1 specific yield (sy1_1 to sy1_164)

leakance between the layers (le1_1 to le1_164)




layer 2 storage coefficient (ss2_1 to ss2_221)


leakance between the layers (le2_1 to le2_156)


layer 3 storage coefficient (ss3_1 to ss3_156)


Zone based rainfall, flood recharge (prain1 to prain8 and fflux to fflux) and evapotranspiration (pevt1 to pevt9) parameters were also included as adjustable parameters. The number of river reaches was increased from one to forty one (riv1 to riv41) to allow better estimates of river/aquifer interaction.

The locations of pilot points used for layer 2 of the model (Lower Cowra Formation) are shown in Figure 4-1. For the other layers, with lesser active area, a subset of these was used. Model parameters representing different hydraulic properties at each of the pilot points are named uniquely.

This nomenclature is summarised in Table 4-1.

Table 4-1 Model Parameters

LAYER Hydraulic Property No. of Pilot Points Parameters Names1 Hydraulic Conductivity 164 kx1_1 to kx1_1641 Specific yield 164 sy1_1 to sy1_1641 Leakance 164 le1_1 to le1_1642 Hydraulic Conductivity 221 kx2_1 to kx2_2212 Specific yield 221 sy2_1 to sy2_2212 Leakance 156 le2_1 to le2_1562 Storage coefficient 221 ss2_1 to ss2_2213 Hydraulic Conductivity 156 kx3_1 to kx3_1563 Specific yield 156 sy3_1 to sy3_1563 Storage coefficient 156 ss3_1 to ss3_156

Rainfall 8 prain 1 to prain 8Flood 8 fflux1 to flux8Evapotranspiration 9 pevt1 to pevt 9River 41 riv1 to riv 41

Total 1845

All parameters in each group assumed an initial value equal to the average parameter value obtained from a previous model by Coffey (2006) and Barnett &Muller, (2008) with some adjustments based on available pumping test analysis. Furthermore, all parameters in each group were subjected to the

same constraints in the form of minimum and maximum values.

Altogether, there were 1845 parameters, 16836 observations with non-zero weight and 17 observation groups listed in the PEST control file. The SVD-assist parameter estimation process requires a pre-

SVD-assist PEST run which is carried out specifically for the purpose of calculation of derivatives. SVD-assisted parameter estimation was then carried out using 600 super parameters which are essentially linear combinations of base parameters.



Figure 4-1 Location of pilot points in the Lower Cowra Formation

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4.2 Final estimates of aquifer parameters

The calibration of model parameters was a major task. The calibrated parameters include horizontal hydraulic conductivity (Kh) for all layers, VCONT (vertical leakance) between layer 1 and layer 2 and layer 2 and layer 3; storage coefficient (S) of the lower layers, which are unconfined/confined; and

specific yield (Sy) of the layer1, which is unconfined. The calibrated hydraulic conductivity values of Upper Cowra vary from 30 to 0.01 m/d; for the Lower Cowra layer the values range from 40 to 0.01 m/d. The Lachlan Formation has conductivity values ranging from 1 to 100 m/d. The calibrated values

of minimum and maximum specific yield of layer 1 are between 0.02 and 0.3 respectively. The calibrated specific storage (Ss) ranges from 10-4 to 10-6 for deeper layers.

Figure 4-2 shows the calibrated horizontal hydraulic conductivity (Kh) values for the Upper Cowra

Formation. A variation in Kh values is evident in this diagram. Areas of high Kh exist along the ancient Lachlan palaeo channel part of the model area.. These areas have values between 5 and 30 m/d. Most of the Upper Cowra aquifer has Kh values between 5 and 10 m/d.



Figure 4-3 shows the calibrated Kh values for the Lower Cowra Formation. A large part of this layer shows moderate to high values in the range of 5 to 35 m/d. Values are higher in the Lower Cowra Formation than in the Upper Cowra Formation.

For the Lachlan Formation horizontal hydraulic conductivity values vary between 1 and 100 m/d over the model area as shown in Figure 4-4.

In auto-calibration changes to specific yield (Sy) values were typically aimed at improving the

calibration for the upper layer of Cowra. With lower Sy values, the model would typically become more sensitive to recharge rates, and would tend to create higher simulated heads in layer 1. Figure 4-5 shows the distribution of (Sy) values for layer 1. These values range from 0.06 to 0.14, indicating a

medium degree of variability in the sediments of the layer1 formation.

Parameters representing the storage coefficient (S) of the Lower Cowra and Lachlan Formations were important. Changes to S values were usually aimed at increasing or decreasing the simulated

pressure ranges to match those caused by seasonal pumping. This typically required orders-of-magnitude changes in S for each run. The layer 2 formation storage coefficient distribution in Figure 4-6 shows values around 10-6, with little spatial variability. The storage coefficient in the Lachlan

Formation is about 8.8e-5 with very little spatial variability as shown in Figure 4-7.

Figures 4-8 and 4-9 show the calibrated vertical leakance VCONT values for the Upper Cowra Formation (layer 1) and the Lower Cowra Formation (layer 2), respectively. VCONT values are

significantly higher in layer 1, ranging from 0.01 to 0.001 m/d.

Calibrated river conductance is represented in Figure 4-10. It varies from 1 to 2000 m2/d/km. The conductance is, nevertheless difficult to assess by model calibration, as it can be varied by several

orders of magnitude without much apparent effect as discussed by Merrick, (1989).

The remaining calibrated parameters are listed in Table 4-2.



Figure 4-2 Hydraulic Conductivity (m/d) distributions in Upper Cowra (Layer 1)

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Figure 4-3 Hydraulic Conductivity (m/d) distributions in Lower Cowra (Layer 2)

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Figure 4-5 Specific yield distributions in Upper Cowra

0.06



Figure 4-6 Storage Coefficient in Lower Cowra

Figure 4-7 Storage Coefficient in Lachlan Formation



Figure 4-8 Vertical Leakance (1/d) between Upper and Lower Cowra

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240241

242243244245

246

247248249250

251252253

254

255256

257258

259 260

261

262

263 264

265

266

267

268 269 270

271272273

274 275

276277

278 279

280281

282 283

284285

286 287 288

289 290

291 292 293

294295

12

34

56

7

89

1011

12 13

1415

16

17

1819

20

212223

24

25

2627

2829

303132

33

34

353637

3839

4041

42

434445

46

47

48

49

50

12

34

5

6

7

8

910

11

1213

1415

1617

18

192021

222324

2526

2728

292930

1

23

45

6 7 8

91011

121314

151617

181920

2122

2324

25

2627

28

29 30 31

32 33 34

35

3637

38

12

34

56

7

8

910

1112

1314

15

16

17 18

1920

21

22

23

242526

2728

29

3031

32 33 34 35

363738

39 40

41

424344

4546

4748

49

5051

5253

545556

5758

59

60 61 62

63

6465

6667

68

6970

71

7273

74

75

7677

78

79

808182

8384

85

86

87

88

89

9091

92

9394

1234567891011121314

15

16

17181920

212223242526

27282930

31

32 33

34

35

36 37 38 39 40

414243

44 45

464748

4950

5152

5354

5556575859

606162

63646566676869707172737475

76

777879808182

83

84

858687888990919293

94

95

96

97

98

99

100

101

102103104105

106107108109

110111

112113114

115116

117

118119120

121

122

123

124125

126

127

128129

130 131

132133

134 135

136137

138

139140

141

142143

144 145

146

147148

149150151

152

153154155

156 157

158159160

161162

163 164

165166167

168

169

170171172

173174175176177178

179

180

181

182

183

184

185

186

187

188189190

191

192

193194

195

196197198

199

200

201

202203204205

206207208

209210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226227

228

229230

231

232

233234235

236237

238239

240241

242243

244

245246

247

248249

250251

252253

254

255

256

257

258

259

260

261

262

263

264

265

266267

268

269

270271

272273274275276

1 2

3 4 5

67

8 9

10 11

1213

14151617

1819

20

21222324

25

26

27 28

29

303132

3334

3536

37 38

39

4041

42 43

44 45

46474849

5051

5253

54

1

23

4 5 6

7

8 9 10

111213

1415

1617

18

1920

2122

2324

25

26

27

2829

30

31

32

33

34

35 36

37

3839

40

4142

43

44

4546

4748

4950

5152

535455

565758

596061

62

636465

6667

68697071

727374

757677

787980

81

82 83 84

8586

8788

89 90 91

9293

*

*

*

*

*

*

*

*

*

*

41

41

*

200

2

203

3

412009

412030

*

**

Node3

412011*

*

*

*

412072

* ****

Goobank Ck

LACHLAN R

Mendagery Ck

323

14

598

130

314

202

19992000

10

11

10262

59

2000466

223

583

59904

341

127135

36103

3493

1682

473

250

85

28

133

428

1

2000

132

1

147

146

1


Table 4-2 Calibrated Model Parameters.

RIVERRiver Bed Hydraulic Conductivity RAINFALL

Parameter m2/d/km Parameter Rate (%)riv1 323.5 prain1 1.9riv2 14.3 prain2 0.1riv3 598.0 prain3 2.9riv4 130.2 prain4 3.0riv5 313.6 prain5 0.1riv6 20.4 prain6 0.1riv7 2.5 prain7 3.0riv8 1999.2 prain8 3.0riv9 1999.9riv10 10.0riv11 10.6riv12 10.1riv13 262.4 FLOODriv14 58.6 Parameter mmriv15 2000.0 fflux1 0.2-5riv16 145.6 fflux2 0.2-5riv17 465.5 fflux3 0.2-5riv18 222.9 fflux4 0.05-1.25riv19 583.4 fflux5 0.2-5riv20 58.7 fflux6 0.05-1.25riv21 904.3 fflux7 0.05-1.25riv22 341.4 fflux8 0.2-5riv23 127.0riv24 135.4 EVAPORATIONriv25 36.1 Parameter Rate (%) Extinction Depth (m)riv26 103.1 pevt1 5 6riv27 33.7 pevt2 1 4riv28 93.5 pevt3 25 9riv29 1681.6 pevt4 5 4riv30 472.6 pevt5 7.5 4riv31 250.1 pevt6 25 9riv32 84.8 pevt7 25 8riv33 27.8 pevt8 4.8 3riv34 132.8 pevt9 4.9 5riv35 428.0riv36 1.0riv37 2000.0riv38 131.9riv39 1.0riv40 1.0riv41 147.2



4.3 Head response

Plots of observed and simulated hydrographs for each calibration bores are presented in Appendix 6. These comparison plots are presented in eight groups primarily based on their location. The locations

of these bores are shown in Appendix 5. There are total 174 hydrograph in Appendix 6.

Except in zone 7, most monitoring bores show that water levels in layers 1 and 2 sharply increased in response to the flood event of 1990. Following the flood event water levels remained generally steady

until the year 2000. After that the water levels show a sharp decline which is attributed to increased groundwater usage coupled with drought conditions.

Most of the monitoring bores in layer 3 also follow the same trend as that observed in layers 1 & 2.

However, at some of the calibration bores, simulated water levels do not fluctuate as much as the corresponding observed water levels. In particular, predicted drawdowns are often less than that measured. This may be attributed to the lack of monthly pumping data. Accurate monthly pumping

records are necessary to quantify the amount of aquifer stress. Pumping records are not reliable before 1998 and after this only annual totals were reported. But the groundwater model simulates monthly stress period and ideally requires monthly pumping values.

Simulated and observed water levels in zone 7 do not match well suggesting the model is poorly calibrated in this area. A poor match in this area was also noted in Coffey (2006). In zones 1 and 2 the simulated and observed heads show a similar trend but simulated values are higher than observed

values in all layers. Reasons for these mismatches are unclear but it is likely that knowledge of the local geology was not sufficient to have allowed construction of a realistic model in this area.

In the remaining zones the model mostly matches the observed pattern well.

4.4 Calibration assesment

The modelling guidelines by Middlemis, et al., (2001) recommend evaluation of the degree of calibration of a groundwater model using both qualitative (visual comparison) and quantitative (statistical) means. Quantitative measures assessing calibration usually involve mathematical and

graphical comparisons between measured and simulated aquifer heads and the calculation of statistics regarding residuals.

Figures 4-11 to 4-13 provide, for each layer, scattergrams of the simulated water levels. In diagrams of

this sort, a 45o line through the origin represents a perfect calibration with a coefficient of determination of one (R2 = 1). The extent of scatter about this line is regarded as a measure of the goodness of model calibration. Some minor discrepancies between the observed and simulated aquifer heads are

to be expected in a model of this magnitude. Low SRMS (scaled root mean square) value (less than 5%) is normally regarded as another indicator of a well calibrated model. According to these criteria, this model is well calibrated. For layer 1, simulated values are closely clustered about the 45o line with a root mean square (RMS) of 2.01 meters and a mean sum of residuals of 1.41 meters for 3175 observation data.



Figure 4-11 Layer 1 Scattergram of modelled versus measured heads and statistics results.

Sum of Squares (m**2) SSQ = 12784.33 m**2Mean Sum of Squares (m) MSSQ = 4.03 mRoot Mean Square (m) RMS = 2.01 mScaled Root Mean Square (%) SRMS = 1.37 %Root Mean Fraction Square (%) RMFS = 0.87 %Scaled Root Mean Fraction Square (%) SRMFS = 1.30 %Sum of Residuals (m) SR = 4479.08 mMean Sum of Residuals (m) MSR = 1.41 mScaled Mean Sum of Residuals (%) SMSR = 0.96 %Coefficient of Determination (tend to unity) CD = 0.98

y = 1.0057x - 0.1619

R2 = 0.9967

150

170

190

210

230

250

270

290

150 170 190 210 230 250 270 290

Measured mAHD

Mo

del

led

mA

HD



The scattergram plot of Layer 2 Figure 4-12 shows scatter with a RMS value of 4.84 metres for 7515 observation data points.



y = 1.0251x - 2.5559

R2 = 0.9892

150

170

190

210

230

250

270

290

310

150 170 190 210 230 250 270 290

Measured m AHD

Mo

del

led

m A

HD



The scattergram for layer 3 shown in Fig. 4-13 recorded a RMS of 7.16 meters for 5948 observation data points.



y = 0.9813x + 9.6177

R2 = 0.9779

150

170

190

210

230

250

270

290

310

150 170 190 210 230 250 270 290 310

Measured mAHD

Mo

del

led

mA

HD

Figure 4-14 is a plot of the simulated heads versus the observed heads for all observations in all layers over the calibration period. RMS of 5.45 m, scaled RMS of 3.4% and sum of mean residual

values of 2.10 m for a total of 16836 observation data points indicates reasonably good calibration performance. Middlemis et al. (2001) suggested a criterion of about 5% for the scaled RMS to be regarded as a well calibrated model. A correlation coefficient of 0.9892 (nearly 1) also indicates a

strong relationship between the simulated and the observed heads.

Second plot presents the distribution of residuals (the difference between observed and simulated head) in all layers. A positive residual indicates an underestimate by the model where as a negative

residual is an overestimate. The plot indicates overall that the model slightly over estimates the water levels over the model domain. In summary 70% of simulated heads in all layers are within 1 metre of the corresponding observed water levels.



Figure 4-14 All Layers calibration assessment: scattergram of modelled versus measured heads, statistics and distribution of residuals results.

Sum of Squares (m**2) SSQ = 493671 m**2Mean Sum of Squares (m) MSSQ = 29.67 mRoot Mean Square (m) RMS = 5.45 mScale Root Mean Square (%) SRMS = 3.40 %Root Mean Fraction Square (%) RMFS = 2.08 %Scaled Root Mean Fraction Square (%) SRMFS = 2.88 %Sum of Residuals (m) SR = 34976.63 mMean Sum of Residuals (m) MSR = 2.10 mScaled Mean Sum of Residuals (%) SMSR = 1.31 %

y = 1.0175x - 0.8612

R2 = 0.9892

150

170

190

210

230

250

270

290

150 170 190 210 230 250 270 290

Measured mAHD

Mo

del

led

mA

HD

0

10

20

30

40

50

60

70

80

90

100

-5 -4 -3 -2 -1 0 1 2 3 4 5

Residual m

Pro

bab

ility

%



4.5 Sensitivity analysis

.A product of the use of PEST is a table of parameter sensitivity values that provides a guide to the relative extent to which each model adjustable parameter affects the simulated groundwater levels.

The most sensitive parameters make a significant contribution to the behaviour of the model while those that are least sensitive contribute very little and have a wide range of acceptable values. The parameter sensitivities that PEST provides are not absolute measures. They vary, depending on the

parameter combinations used. Nevertheless, they provide a very useful guide to the relative importance of the adjustable model parameters.

Figure 4-15 shows a plot of parameter sensitivities provided by PEST for the parameter set chosen to

represent the calibrated model. Because of the large number of adjustable model parameters, only the 50 most sensitive parameters are represented for each layer in the diagram.

Evapotranspiration parameters are the most sensitive and river, hydraulic conductivity specific yield

and flood seem to have a moderate influence on model outcomes. Storage coefficient is the least sensitive of model parameters



Figure 4-15 Adjustable Model Parameter Sensitivities

Layer 1

0.00E+00

2.00E-03

4.00E-03

6.00E-03

8.00E-03

1.00E-02

1.20E-02

1.40E-02

1.60E-02

1.80E-02

2.00E-02p

evt

8p

evt

4riv

18

pe

vt9

fflu

x3p

evt

2riv

3riv

19

riv4

1ffl

ux6

riv2

6sy

1_

39

riv1

0riv

33

riv3

1riv

28

sy1

_1

3sy

1_

27

sy1

_0

8sy

1_

35

riv1

2sy

1_

37

sy1

_1

6sy

1_

36

riv4

fflu

x1sy

1_

32

sy1

_3

4riv

38

pra

in3

sy1

_8

8p

rain

1sy

1_1

21

sy1_

11

7sy

1_

14

sy1

_8

2sy

1_1

49

sy1_

14

7sy

1_

58

fflu

x7riv

36

sy1_

12

0sy

1_

64

sy1_

12

3sy

1_1

35

sy1

_3

3sy

1_

67

sy1_

13

6sy

1_

12

riv9

Parameters

Sen

siti

vity

Layer 2

0.00E+00

2.00E-03

4.00E-03

6.00E-03

8.00E-03

1.00E-02

1.20E-02

pevt

8sy

2_21

8kx

2_21

6pe

vt4

sy2_

214

riv9

kx2_

205

kx2_

204

riv18

sy2_

186

sy2_

93pe

vt9

pevt

2kx

2_96

sy2_

98sy

2_18

3kx

2_89

kx2_

203

sy2_

163

sy2_

92sy

2_20

4ff

lux3

kx2_

206

sy2_

181

sy2_

187

riv3

kx2_

218

sy2_

215

sy2_

212

sy2_

182

kx2_

196

kx2_

209

sy2_

190

riv31

riv11

sy2_

198

sy2_

221

kx2_

187

kx2_

109

kx2_

195

sy2_

194

kx2_

186

riv32

sy2_

191

sy2_

196

sy2_

210

fflu

x6sy

2_21

3riv

12sy

2_19

3

Parameters

Sen

siti

vity

Layer 3

0.00E+00

2.00E-03

4.00E-03

6.00E-03

8.00E-03

1.00E-02

1.20E-02

pevt

8pe

vt4

pevt

2riv

18pe

vt9

le2_

58kx

3_49 riv3

kx3_

84 riv9

riv11

kx3_

89kx

3_40

le2_

59kx

3_73

kx3_

23le

2_85

kx3_

67ff

lux3

kx3_

120

kx3_

97pr

ain1

kx3_

41kx

3_48

kx3_

53kx

3_19

kx3_

69kx

3_38

kx3_

47kx

3_37

kx3_

155

riv31

kx3_

119

riv10

le2_

84kx

3_92

le2_

97kx

3_14

le2_

41kx

3_88

kx3_

144

riv12

kx3_

70le

2_47

kx3_

36kx

3_42

kx3_

75kx

3_15

6kx

3_66

kx3_

12

Parameters

Sen

siti

vity



4.6 Water balance

The water balances presented in this chapter are based on the most recent calibration run which spans the 22 years from July 1986 to June 2008 and they pertain to the whole of the model area is

shown in Figure 2.7. Figure 4-16 presents a summary of water balance components for the calibrated model showing annual volumes averaged over the 22 year calibration period.

Figure 4-16 Model Water Balance Summary for July 1986 to June 2008

GroundwaterET River_out Pumping

Irrigation Flood Rainfall 118.52 River_in 17.02 17.77

9.54 14.63 109.12 53.19

2.89 storage change30.27 UP

Budget averaging period 1986 - 2008All volumes are in GL/year

Figure 4-16 summarises the amount of water being transferred into and out of storage by stresses

such as rainfall, irrigation, river, flood, evapotranspiration, boundary flows and extraction.

The annual average total recharge from all sources in the calibration period is 186.47 GL. This figure represents a summation of contributions from rainfall recharge, river, flood, irrigation,

evapotranspiration and lateral flow. The average rainfall recharge is about 58.5 % of the total recharge. River, flood and irrigation recharge contributions relative to total recharge are 28.5%, 7.8% and 5.2%, respectively.

The total annual average outflow in the GWMA 011 is 156.20 (118.52+17.02+17.77+2.89) GL. The evapotranspiration is about 75.8% of this total while the groundwater abstraction makes up 11.4%. River and lateral flow contributions relative to total outflow are 10.9% and 1.9%, respectively.

Evaporation is the dominant discharge source over the calibration period.

Figure 4-17 provides a breakdown of a water budget on a layer basis. The groundwater usage figures averaged over the 22 years are deceptive since heavy pumping started after 2000.




Figure 4-17 Average Annual water balance for individual layers for July 1986 to June 2008

GroundwaterRain+Flood+Irr River_in River_out Pumping ET

17.02 1.36 117.71

130.27 53.19

Out storage change0.22 28.59 UP

UP

UP

GroundwaterPumping ET layer 1

Rain+Flood+Irr 3.41 0.81 58.08

2.9576.62

Out1.00 storage change

0.83GroundwaterPumping 21.96 layer 2

Rain+Flood+Irr 12.99

0.0737.40

Out1.68 storage change

0.84 Budget averaging period 1986 - 2008All volumes are in GL/year

layer 3

It is important to realise that the recharge calculated is distributed over the entire model area which may not occur in practice in certain area thus the aquifer

system cannot cope with high rates of groundwater extraction (even if they are consistent with recognised sustainable yield). This has direct implications for the area of high yielding bores around Forbes and Cowra.


5. Scenario runs

An objective of the groundwater flow model was to generate various scenarios for aquifer

management purposes. ‘Dry’, ‘wet’ and ‘medium’ scenarios were formulated to examine the aquifer behaviour under “no pumping”, “current development” and “entitlements” conditions. It is hoped that the results of these scenarios will aid in the formulation of an appropriate aquifer management

strategy for the Upper Lachlan Aquifer system.

The selection of ‘dry’, ‘wet’ and ‘medium’ conditions is based on the historical rainfall pattern going back about 100 years. These data sets identified as Cdry, Cwet and Cmed. were supplied by CSIRO.

Each set of climate data was used to prepare relevant MODFLOW recharge and evapotranspiration packages.

For the MODFLOW river package, Integrated Quantity and Quality Model (IQQM) model generated

monthly flow data for the chosen period were converted to corresponding monthly river stage at gauging stations along the Lachlan River, Belubula River, Goobank Creek and Back Creek for each climatic variation (Cdry, Cwet and Cmed).

For the ‘wet’ scenario five flood events were applied over the 100 year period, based on exceedance of the river stage height of 5.7 metres at the gauging stations 412004 and 412002 in Figure 3-11. With the same criterion, three flood events were applied for the ‘dry’ and ‘med’ climatic variations. Floods

were applied over the area inundated by the 1990 flood.

Irrigation recharge was maintained at the 2000/2001 level in the absence of any other irrigated area spatial distribution data.

Heads at outflow CHD boundaries were fixed at long–term average values.

The three different climatic variation scenarios were run for three different groundwater extraction limits: ‘no pumping’, ‘current development’ and ‘maximum allocation’. The combination of three climate

scenarios and three pumping scenarios yielded nine scenarios in total.

The ‘no pumping scenario’ represents the natural condition where zero pumping occurs. The ‘current development scenario’ corresponds to the 2006-2007 water year in which the highest groundwater

usage (84.6 GL) was recorded. These data sets were applied from the end of the calibration period to June 2108. In order to assess the current development situation. The ‘entitlements’ scenario corresponds to the maximum allocation limit of 174.6 GL/year. These data were recycled 100 times to

allow simulation to year 2108.

All nine scenarios (‘dry_no pumping’, ‘dry_current development’, ‘dry_maximum allocation’, ‘wet_no pumping’, wet_current development’, ‘wet_maximum allocation’, ‘med_no pumping’, ‘med_current

development’ and ‘med_maximum allocation’) were applied from the end of the calibration period (July 2008), finishing at June, 2108.

5.1 Scenario water balance

Scenario results are provided in Figures 5-1 to 5-3. These diagrams show water balance components (GL/yr) averaged over the 100 year period.

The major differences in the dry, wet and medium scenarios relate to groundwater pumping.

Comparison of the ‘dry_current development’ with ‘dry_maximum allocation’ scenario result show river leakage is greater by 5 GL/yr and evapotranspiration deplete from 138 to 120 GL/yr. The ‘dry_no

pumping’ scenario shows that evapotranspiration was increased to 171 GL/yr and net river leakage decreased from 100 GL/yr to 62 GL/yr (Figure 5.1). For the wet scenario recharge (rainfall+flood+irrigation) is 146 and net river leakage is 106 GL/yr in wet_max_allocation scenario,



however in the wet current development river net leakage declined to 101 and evapotranspiration rose up to 178 GL/yr. Wet no pumping scenario net river leakage is 67 GL/yr in Figure 5.2.

These illustrate that if there was no pumping in the region, water levels would have risen causing river

leakage to decrease and evapotranspiration to increase. If there was high pumping, water level would have depleted causing evapotranspiration to decrease and river leakage to increase.

Evapotranspiration is the dominant discharge process over each scenario run.

In the early stages of each scenario run, it was noted that some of the bores failed to maintain the pumping rates specified in the model and as a result of those pumping locations became dry (as shown in Figures 5-4 to 5-6). Water levels in these areas can exhibit gradually declining trends. In the

dry, wet and med scenarios with the maximum allocation, the groundwater system reaches a new equilibrium after year 55 and the system maintains groundwater pumping rates at approximately 96-99 GL/yr.

Net river leakages over the one hundred year period from 1895 to 1995 in each scenario are shown in Figure 5-7 to 5-9. As expected river leakage increases with pumping in all three scenarios.




Figure 5-1 Average Annual water balance over dry scenario run June 2008 to July 2108

Rain+Flood+Irr Riv in Riv out ET Well108 78 16 171 0

CH GL/yr2 storage In 186

storage Out 189

Dry_No_Pumping

Dry_Current_Development

Dry_Max_Entitlements



storage Out 212

Rain+Flood+Irr Riv in Riv out ET Well

107 103 3 120 102


storage Out 226



Figure 5-2 Average Annual water balance over medium scenario run June 2008 to July 2108



storage Out 212

Medium_No_Pumping

Medium_Current_Development

Medium_Max Entitlements



storage Out 233

Rain+Flood+Irr Riv in Riv out ET Well

126 107 3 137 104


storage Out 247



Figure 5-3 Average Annual water balance over wet scenario run June 2008 to July 2108


CH3 G

storage In 231storage Out 234

L/yr


CH3 GL/yr



CH3 GL/yr


Wet_No_Pumping

Wet_current_Development

Wet_Max_Entitlements


Figure 5-4 Dry Scenario yearly groundwater extractions over the 100 year simulation

Dry Scenario

60000

80000

100000

120000

140000

160000

180000

0 10 20 30 40 50 60 70 80 90 100

yr

ML

/yr

dry_current_develop_ML/yr pump_dry_max_allocation

Figure 5-5 Med Scenario yearly groundwater extractions over the 100 year simulation

Mid Scenario

60000

80000

100000

120000

140000

160000

180000

0 10 20 30 40 50 60 70 80 90 100

yr

ML

/yr

pump_mid_current_develop pump_mid_max_allocation



Figure 5-6 Wet Scenario yearly groundwater extractions over the 100 year simulation

Wet Scenario

60000

80000

100000

120000

140000

160000

180000

0 10 20 30 40 50 60 70 80 90 100

yr

ML

/yr

pump_w et_current_devel pumping_w et_max_allocation

Figure 5-7 Dry Scenario yearly net river leakage over the 100 year simulation

Dry River Net

0

20000

40000

60000

80000

100000

120000

140000

160000

0 10 20 30 40 50 60 70 80 90 100

yr

Riv

er L

eaka

ge

Net

M

L/y

r

dry_current_develop_ML/yr Riv Net_dry_max_allocation dry_nopuming_RivNet ML/yr



Figure 5-8 Mid Scenario yearly net river leakage over the 100 year simulation

Med River Net

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

0 10 20 30 40 50 60 70 80 90 100

yr

Riv

er L

eaka

ge

Net

tM

L/y

r

Riv Net_mid_current_develop Riv Net_mid_max_allocation RivNet_mid_nopumping

Figure 5-9 Wet Scenario yearly net river leakage over the 100 year simulation

Wet River Net

0

20000

40000

60000

80000

100000

120000

140000

160000

180000

0 10 20 30 40 50 60 70 80 90 100

yr

Riv

er L

eaka

ge

Net

t M

L/y

r

RivNet_w et_current_develop RivNet_w et_max_allocation RivNet_w et_nopumping



6. Conclusions and recommendations

A groundwater flow model for the Upper Lachlan Valley has been developed to improve the

understanding of the regional flow system, assess the quantity of water within the system and the amount of recharge to the aquifer and to evaluate the impact of climate change on the water balance for the regional aquifers within the valley.

The model was developed using MODFLOW (McDonald and Harbaugh, 1988) with a non uniform grid for this study. Grid cell dimensions vary from 500 m in the vicinity of the Lachlan River and increase progressively to 2000 m at distance from the river to the north and south. The model grid is rotated 20

degrees anti clockwise. The model calibration period is July 1986 to June 2008. The model consists of four layers that correspond to each of the major aquifers:

Layer 1: the unconfined Upper Cowra

Layer 2: the confined/unconfined Lower Cowra

Layer 3 the confined/unconfined Lachlan Formation

Layer 4 the confined/unconfined fractured rock (inactive layer)

The groundwater flow model identified the main recharge components as rainfall recharge, river leakage, flood recharge and irrigation recharge, whilst evapotranspiration is the major discharge component followed by groundwater usage. The aquifer outflow is to the west.

Non linear parameter estimation (PEST) was used to aid calibration of the model based on water levels from observation bores. Assessment of the model’s performance, based on comparison between observed and simulated groundwater levels for the entire calibration period, indicates that, for

all model layers, a good match was generally achieved except in zone 7. Low SRMS (scaled root mean square) values (less than 5%) were achieved for all three layers which confirm that the model is well calibrated.

This groundwater model simulates monthly stress periods and requires usage data at a monthly frequency. However from 1998 onwards groundwater usage data in the model have only annual frequency. There is little usage data available prior to 1998. This shortcoming in the groundwater

usage data set constrained the model calibration in some cases.

The water balance summary for the 22 year period of the model (July 1986 to June 2008) shows an annual average total recharge of 186.48GL. This figure represents an average over the model spatial

domain and calibration period. It is not representative of recent conditions and takes no account of spatial variability. In practice, pumping is concentrated in small areas and has increased significantly in recent years. This pattern of usage is likely to affect local water levels and may diminish local

extraction potential unless sufficient recovery occurs. The model will be of value in investigate local usage scenarios. The total annual average outflow is 156.30 GL. The evapotranspiration is about 76% of this total. Therefore evapotranspiration is the dominant output over the calibration period.

Three climate scenarios (dry, wet and med) were undertaken to evaluate the aquifer’s response to different levels of groundwater pumping. The ‘no pumping scenario’ water budget revealed the likelihood of rising water levels, reduced river leakage and increased evapotranspiration in the

absence of pumping for all climatic scenarios. The increased pumping scenario showed, water level depleted causing evapotranspiration to decrease and river leakage to increase in all scenarios.



It is recommended in future attempts to revise this model the following aspects are given consideration:

Poor calibration of bores in Zone 7 is attributed to the complexity of the groundwater system

in this area. More geological investigations are needed to obtain a proper understanding of the hydrogeological framework of the area.

Review the hydrogeological framework of the alluvial’s in zone 1 and 2.

Independent studies of the groundwater recharge process (for example, hydrochemical characterisation) could enhance calibration of the groundwater model particularly Zone 1, 2

and 7.

Annual monitoring of groundwater production bores constrains the integrity of groundwater usage data. The requirement for monthly usage data for groundwater modelling purposes

necessitates assumptions regarding temporal distribution of production. Therefore, it is recommended that, particularly in critical areas of groundwater usage, selected landholders be requested to provide monthly meter readings of production with additional data such as

pumping on/off times and a log of associated management decisions.

Some discrepancies between observed bore data and corresponding model-simulated data are attributed to the likelihood that a few existing groundwater extraction sites are not

represented in the model. Future model enhancement should seek to assess the veracity of this suspected cause.

Improved estimate of irrigation recharge based on landuse, crop patterns and combined

usage of surface and groundwater.

Verification of this model has not been undertaken. Since almost all suitable observation data

sets were used to calibrate this model, spatial verification is not possible. However, temporal verification remains an available option at a future time since over two years of observation data have accumulated since the end of the calibration period of this model.




7. References

Anderson, J., Gates. G., and Mount, T.J., 1993. Hydrogeology of the Jemalong and Wyldes Plains

Irrigation Districts, NSW Department of Water Resources.

Barnett, B.G and Muller, J., 2008. Upper Lachlan Groundwater Model calibration Report Draft, SKM Bilge, H., 2001, Lower Gwydir Valley Groundwater Model, CNR, Department of Land and Water Conservation

Bilge, H., 2007, Lower Macquarie Groundwater Flow Model, Water Management Division,

Department of Water and Energy

Bish, S. and Gates, G., 1991. Groundwater reconnaissance survey: Forbes – Condobolin-Lake Cargelligi, NSW Dept. Water Resources, T.S.91.033. Chiang, W. H. and W. Kinzelbach. 1996. Processing Modflow (PM), Pre- and postprocessors for the simulation of flow and contaminant transport in groundwater system with MODFLOW.

Coffey 2006. Cowal Gold Mine Groundwater Supply Modelling Study Model Calibraion, Coffey Geosciences Pty. Ltd. S21910/02

Dawes WR, Stauffacher M. and Walker GR. 2000. Calibration of Modelling of groundwater process in

the Liverpool Plains. CSIRO Land and Water Technical report 5/00. February

Demetriou, C., 1995b, Computer program VMRIVER - pre-processor for time varying river in MODFLOW Format, CNR, Department of Land and Water Conservation.

Doherty, J., 2005, PEST Model-Independent Parameter Estimation User Manual (5th edition). DWR. 1994. Review of Groundwater Use and Water Level Behaviour in the Upper Lachlan Valley 1986-1994, Status Report No. 2. Department of Water Resources Technical Services Division TS 94.078 authored by S Bish and R.M Williams Hydrogeology Unit.

Gates, G.W.B and Williams, R.M., 1988. Dryland salinity study: Changes in groundwater levels southeast NSW, NSW Dept. Water Resources, T.S. 88.010.

McDonald, M.G and Harbaugh A.W., 1988, A modular three- dimensional finite difference groundwater

flow model. U.S. Geological Survey, Reston, Virginia.

Megalla, M.N and Kalf F.R.P., 1973. buried Channel of the Lachlan from Cowra to Forbes, NSW, Water Conservation and Irrigation Commission NSW

Merrick, N.P. 1989, Lower Namoi Valley Groundwater Model. Department of Water Resources, Heritage Computing.

Murray Basin Hydrogeological Map Series CARGELLIGO scale 1:250 000

Middlemis, H., Merrick, N. P. & Ross, J. 2001, Groundwater flow modelling guideline, Aquaterra Consulting Pty Ltd Report for Murray Darling Basin Commission, Project no. 125, January 2001.

Muller, R. and Lennox, G., 1999. Review of Groundwater trends in the Lachlan Valley Upstream of

Lake Cargelligo, Central West Region CW GWS 99/1

O’Rourke, M., 2007. Upper Lachlan Groundwater Source Status Report 2007.

Salotti, D., 1997, Borambil Creek Groundwater Model. Department of Land of Water Conservation.


APPENDIX 1: Model geometry

Ground Surface Elevation (m AHD)

150

200

250

300

350

400

450

500

550

600

650

700

750

800



Layer1 thickness (m)

450000 500000 550000 600000 650000

6200000

6250000

6300000

6350000

20

Forbes

Parkes

CowraGrenfell

Condobolin

West Wyalong

Temora

Lake Cargelligo

UPPER COWRA THICKNESS

5

12

15

20



Layer 2 thickness (m)

450000 500000 550000 600000 650000

6200000

6250000

6300000

6350000

Forbes

Parkes

CowraGrenfell

Condobolin

West Wyalong

Temora

Lake Cargelligo

LOWER COWRA THICKNESS

0

10

20

40

60

80

100

120

140



Layer 3 thickness (m)

450000 500000 550000 600000 650000

6200000

6250000

6300000

6350000

Forbes

Parkes

CowraGrenfell

Condobolin

West Wyalong

Temora

Lake Cargelligo

0

5

10

20

30

40

50

60

70

80

90

100

LACHLAN THICKNESS



APPENDIX 2: Initial head

Upper Cowra Initial Heads July 1986 (m) 1986




Lower Cowra Initial Heads July 1986 (m) (AHD)

450000 500000 550000 600000 650000

6200000

6250000

6300000

6350000

Forbes

Parkes

CowraGrenfell

Condobolin

West Wyalong

Temora

Lake Cargelligo

LOWER COWRA INITIAL HEAD JULY 1986 (m) (AHD)

130

150

170

190

210

230

250

270

290

310

330

350

370

390

410


Lachlan Formation Initial Heads July 1986 (m) (AHD)

450000 500000 550000 600000 650000

6200000

6250000

6300000

6350000

Forbes

Parkes

CowraGrenfell

Condobolin

West Wyalong

Temora

Lake Cargelligo

LACHLAN FORMATION INITIAL HEAD JULY 1986 (m) (AHD)

130140150160170180190200210220230240250260270280290300310320330340350360



APPENDIX 3: Production bore locations Table List of Usage Bores

No Licence No Easting Northing No Licence N Easting Northing No Licence No Easting Northing No Licence Easting Northing No Licence Easting Northing No Licence Easting Northing1 70BL003286 653152 6258438 74 70BL128649 602418 6302001 147 70BL226902 579022 6303271 220 70BL11748 638343 6280887 293 70BL22730 529238 6323085 366 70BL23021 539783 62787512 70BL003287 650539 6257524 75 70BL128752 655062 6255696 148 70BL226940 612179 6299359 221 70BL12015 653455 6285454 294 70BL22732 531313 6322685 367 70BL23022 539784 62787523 70BL003292 652985 6259273 76 70BL130274 644903 6267409 149 70BL226958 640438 6281018 222 70BL12027 646803 6281480 295 70BL22734 590709 6303917 368 70BL23022 539794 62787544 70BL004285 652060 6256279 77 70BL130276 645105 6267191 150 70BL226959 639857 6280327 223 70BL12327 652929 6284816 296 70BL22736 536864 6316173 369 70BL23022 539786 62787645 70BL004286 652209 6257078 78 70BL130933 640309 6275108 151 70BL227008 657260 6254453 224 70BL12403 561863 6306314 297 70BL22738 553145 6306233 370 70BL23022 537234 62783516 70BL004294 650310 6257651 79 70BL131104 597999 6307094 152 70BL227009 650098 6253424 225 70BL12508 648698 6281370 298 70BL22738 517382 6335720 371 70BL23022 537235 62783527 70BL005203 637980 6226843 80 70BL131459 603077 6300187 153 70BL227019 573603 6304106 226 70BL12605 651528 6284252 299 70BL22739 522298 6330239 372 70BL23022 537236 62783538 70BL005889 653154 6257101 81 70BL133693 645155 6259586 154 70BL227046 593703 6293614 227 70BL12605 651601 6284005 300 70BL22740 592534 6288574 373 70BL23033 599986 62984249 70BL010324 651153 6255538 82 70BL133695 648703 6263647 155 70BL227087 579703 6302854 228 70BL12641 547180 6268021 301 70BL22740 595581 6294266 374 70BL23037 632206 6279828

10 70BL010764 653202 6258345 83 70BL133701 644563 6267076 156 70BL227122 647127 6255795 229 70BL12673 646435 6281805 302 70BL22740 599702 6296727 375 70BL23066 575328 622471911 70BL013352 647971 6262710 84 70BL133702 646004 6267054 157 70BL227193 596313 6304259 230 70BL12746 647754 6282031 303 70BL22741 585759 6299832 376 70BL23066 517258 632383012 70BL013672 645703 6275575 85 70BL133703 645486 6266815 158 70BL227194 627337 6288053 231 70BL12808 659567 6285355 304 70BL22741 583399 6295939 377 70BL23078 545827 631962013 70BL013842 647096 6270803 86 70BL134615 633894 6277274 159 70BL227202 652903 6255264 232 70BL12859 651168 6284320 305 70BL22742 598208 6292782 378 70BL23085 645975 627363114 70BL014704 590451 6289734 87 70BL135032 647510 6260555 160 70BL227203 650903 6255285 233 70BL13029 654789 6284103 306 70BL22742 594283 6303115 379 70BL23086 587828 630241115 70BL015166 589192 6288606 88 70BL136431 611699 6301000 161 70BL227204 644915 6266485 234 70BL13050 654963 6285720 307 70BL22747 535028 6320366 380 70BL23086 582752 630329416 70BL015982 595264 6297511 89 70BL136510 650162 6255978 162 70BL227235 625813 6290659 235 70BL13160 649897 6281706 308 70BL22750 566055 6309551 381 70BL23104 590441 628973417 70BL016227 651084 6255169 90 70BL137567 572863 6304891 163 70BL227250 643145 6281900 236 70BL13293 510969 6335271 309 70BL22751 560749 6301580 382 70BL23116 628294 630053018 70BL016471 650913 6255285 91 70BL139872 647975 6259519 164 70BL227337 660754 6251657 237 70BL13328 649112 6281486 310 70BL22751 566971 6306590 383 70BL23130 605759 629893619 70BL016764 612239 6300387 92 70BL140178 647252 6272803 165 70BL227449 649013 6251184 238 70BL13369 651571 6260928 311 70BL22754 658485 6283894 384 70BL23136 656481 628275620 70BL017218 645041 6274691 93 70BL141326 645276 6276384 166 70BL227476 591363 6296585 239 70BL13498 631383 6280253 312 70BL22760 513348 6333215 385 70BL23187 557128 624047521 70BL017575 644483 6280571 94 70BL141778 639871 6284306 167 70BL227590 635187 6279474 240 70BL13626 649173 6282102 313 70BL22763 545469 6314259 386 70BL23208 629155 628175822 70BL018017 589435 6300862 95 70BL142074 645073 6273229 168 70BL227745 620109 6296835 241 70BL13630 648627 6281833 314 70BL22764 647352 6273627 387 70BL23209 545752 630818323 70BL018426 650757 6256242 96 70BL142332 647248 6272607 169 70BL227764 642613 6281084 242 70BL13669 557074 6313207 315 70BL22766 546787 6313090 388 70BL23224 607287 630173024 70BL018492 634477 6279391 97 70BL142423 642963 6281709 170 70BL228186 647071 6276939 243 70BL13986 648201 6280946 316 70BL22772 570229 630329125 70BL018543 647483 6257110 98 70BL144990 631373 6279284 171 70BL228233 645591 6275847 244 70BL14094 568658 6309995 317 70BL22772 569931 630273126 70BL019024 581989 6296924 99 70BL154311 645954 6276142 172 70BL228237 646531 6258755 245 70BL14236 627113 6299859 318 70BL22789 643495 627868527 70BL019065 645069 6280131 100 70BL154603 653935 6255991 173 70BL228239 611726 6302104 246 70BL14316 545565 6318600 319 70BL22819 519688 633309028 70BL019113 644313 6267542 101 70BL226068 623014 6299076 174 70BL228247 650238 6255683 247 70BL14350 566700 6303532 320 70BL22826 628601 628272929 70BL019484 644731 6279890 102 70BL226079 646581 6260918 175 70BL228248 645820 6261573 248 70BL15114 572356 6306672 321 70BL22834 628668 630191030 70BL019485 644894 6279795 103 70BL226152 597923 6293934 176 70BL228281 646580 6259413 249 70BL15114 571896 6307322 322 70BL22845 570660 630398331 70BL019676 578921 6316384 104 70BL226153 597913 6293934 177 70BL228467 647071 6276979 250 70BL15191 607539 6304052 323 70BL22851 517372 633572032 70BL020089 597284 6301723 105 70BL226208 608913 6301634 178 70BL228512 646823 6261415 251 70BL15192 608021 6303863 324 70BL22852 609724 622598233 70BL020169 597761 6306681 106 70BL226238 640000 6284273 179 70BL228847 648265 6269866 252 70BL15365 609323 6225894 325 70BL22852 609313 622589434 70BL020229 585381 6297016 107 70BL226271 630875 6280484 180 70BL229254 611329 6302511 253 70BL15385 631406 6280244 326 70BL22863 570284 630249135 70BL020463 642473 6280632 108 70BL226294 627245 6283095 181 70BL229327 639959 6228940 254 70BL15454 609734 6225982 327 70BL22868 606608 630380236 70BL020892 645864 6261734 109 70BL226330 643368 6280095 182 70BL229341 647989 6256878 255 70BL15485 651576 6254632 328 70BL22870 536408 632144037 70BL022423 640029 6230202 110 70BL226362 613529 6298914 183 70BL229342 647473 6257110 256 70BL22600 607103 6304264 329 70BL22886 557158 624047238 70BL022749 627308 6285897 111 70BL226385 646592 6262173 184 70BL229451 645129 6280127 257 70BL22618 571963 6309485 330 70BL22894 568000 630598439 70BL023104 647454 6274225 112 70BL226386 650229 6255773 185 70BL229490 645161 6259584 258 70BL22619 553751 6314540 331 70BL22918 514965 633754140 70BL023683 596956 6306642 113 70BL226407 651466 6256101 186 70BL229528 599258 6297733 259 70BL22622 559264 6316435 332 70BL22919 571501 630471241 70BL023791 602006 6295409 114 70BL226470 647999 6256878 187 70BL229532 640455 6283962 260 70BL22622 564214 6309385 333 70BL22924 552408 628273642 70BL030172 599346 6297747 115 70BL226492 644903 6277868 188 70BL229627 660740 6251663 261 70BL22623 545012 6265729 334 70BL22924 555360 628367843 70BL030536 647623 6270706 116 70BL226498 646482 6275654 189 70BL229700 611707 6300985 262 70BL22624 571863 6308935 335 70BL22925 553071 628563544 70BL030726 602121 6300117 117 70BL226501 648310 6269854 190 70BL229813 647368 6261203 263 70BL22624 571813 6308485 336 70BL22925 553276 628738645 70BL030780 622035 6296644 118 70BL226517 639676 6277962 191 70BL229898 654253 6255624 264 70BL22624 571763 6308135 337 70BL22933 572027 630743946 70BL030836 647781 6260081 119 70BL226518 646532 6258760 192 70BL229983 637212 6280244 265 70BL22624 571713 6307685 338 70BL22933 568763 630578447 70BL030968 640120 6231187 120 70BL226520 647499 6273454 193 70BL230075 644884 6279795 266 70BL22624 571563 6307035 339 70BL22936 530744 632531748 70BL031238 626406 6283969 121 70BL226534 646963 6277534 194 70BL230293 645708 6275581 267 70BL22624 571513 6306485 340 70BL22940 633005 627908349 70BL100181 650986 6258134 122 70BL226535 646713 6277334 195 70BL230492 647283 6272794 268 70BL22638 539113 6317385 341 70BL22942 566671 630324850 70BL106460 589477 6294270 123 70BL226536 650091 6253626 196 70BL230614 597995 6307094 269 70BL22638 658363 6283784 342 70BL22943 574398 630295951 70BL108788 642934 6280410 124 70BL226542 627413 6286684 197 70BL230816 638037 6226896 270 70BL22638 582003 6304686 343 70BL22945 601865 629516052 70BL109839 597424 6306884 125 70BL226549 646208 6272154 198 70BL230919 641673 6280965 271 70BL22638 536874 6316173 344 70BL22951 648760 627043453 70BL109909 648633 6263757 126 70BL226550 609816 6303190 199 70BL231046 631363 6279284 272 70BL22639 572213 6306335 345 70BL22951 648455 627089754 70BL110815 591049 6296781 127 70BL226553 632233 6280034 200 70BL231260 642474 6280674 273 70BL22642 645641 6273473 346 70BL22952 542922 625967555 70BL110913 630911 6281536 128 70BL226573 605058 6324869 201 70BL016663 566772 6310008 274 70BL22659 657713 6284534 347 70BL22954 580585 630284256 70BL114815 647001 6261227 129 70BL226574 628678 6281505 202 70BL016836 567886 6310493 275 70BL22667 551914 6330435 348 70BL22970 650056 625844657 70BL117897 651630 6259818 130 70BL226576 575550 6302120 203 70BL017485 570239 6303331 276 70BL22668 567297 6304330 349 70BL22981 640266 628025058 70BL119764 604267 6299143 131 70BL226600 603359 6305853 204 70BL017550 565502 6301885 277 70BL22673 622641 6294821 350 70BL22989 600614 629804259 70BL119765 604445 6298925 132 70BL226639 646735 6258397 205 70BL018355 545962 6304123 278 70BL22673 661723 6287752 351 70BL22996 649404 625168760 70BL120184 621536 6292441 133 70BL226659 602262 6299749 206 70BL018408 616295 6243494 279 70BL22674 595913 6295335 352 70BL23018 544575 630181861 70BL120393 636567 6279510 134 70BL226681 601394 6298557 207 70BL018741 570284 6302499 280 70BL22675 641173 6280184 353 70BL23020 537622 627843662 70BL120435 644894 6266855 135 70BL226682 611381 6302544 208 70BL020435 653558 6285422 281 70BL22675 566164 6309770 354 70BL23020 539785 627875363 70BL122854 641678 6280921 136 70BL226718 650153 6255144 209 70BL021447 655112 6284195 282 70BL22681 553918 6316081 355 70BL23020 539787 627875564 70BL124101 647037 6258908 137 70BL226742 620493 6297078 210 70BL021616 547041 6267503 283 70BL22681 556459 6315898 356 70BL23020 539789 627875765 70BL124304 645714 6268102 138 70BL226758 628700 6282420 211 70BL021711 647113 6280593 284 70BL22683 552731 6266198 357 70BL23020 539791 627875966 70BL126144 604425 6299511 139 70BL226771 647794 6256334 212 70BL022434 653705 6284957 285 70BL22685 627313 6300309 358 70BL23021 539793 627875167 70BL126171 607214 6301760 140 70BL226789 605962 6303098 213 70BL023260 645716 6273497 286 70BL22698 627890 6300646 359 70BL23021 539567 627767368 70BL126314 597501 6296595 141 70BL226798 628668 6281505 214 70BL030845 566826 6310408 287 70BL22699 529702 6327246 360 70BL23021 539569 627767569 70BL127432 640933 6281086 142 70BL226799 628113 6281234 215 70BL102023 568664 6310764 288 70BL22705 626701 6291204 361 70BL23021 539571 627767670 70BL127699 622190 6293111 143 70BL226862 649913 6255034 216 70BL105679 600624 6298042 289 70BL22707 599109 6295678 362 70BL23021 539573 627767771 70BL128015 643362 6281482 144 70BL226870 650170 6259292 217 70BL107196 629070 6299983 290 70BL22714 656491 6282756 363 70BL23021 539575 627767872 70BL128502 648149 6269259 145 70BL226873 649853 6257514 218 70BL108949 606629 6303811 291 70BL22723 554228 6302728 364 70BL23021 539577 627767973 70BL128554 637209 6280247 146 70BL226876 647655 6256235 219 70BL108950 606587 6304527 292 70BL22725 527063 6324235 365 70BL23021 539579 6277681



APPENDIX 4: River details

River Gauging station and weirs in the model area

380000 400000 420000 440000 460000 480000 500000 520000 540000 560000 580000 600000 620000 640000 660000 680000

6120000

6140000

6160000

6180000

6200000

6220000

6240000

6260000

6280000

6300000

6320000

6340000

6360000

6380000

6400000

412006

412011

412030

412033

412165

412030 412139

412002

412057

412036

412024

412004

412009

412016

412023

412067

412072

412043

412072

weir

weirweir



River stage data for each gauging station

River Levels

-1

0

1

2

3

4

5

6

7

8

9

10

Feb

-80

Feb

-81

Feb

-82

Feb

-83

Feb

-84

Feb

-85

Feb

-86

Feb

-87

Feb

-88

Feb

-89

Feb

-90

Feb

-91

Feb

-92

Feb

-93

Feb

-94

Feb

-95

Feb

-96

Feb

-97

Feb

-98

Feb

-99

Feb

-00

Feb

-01

Feb

-02

Feb

-03

Feb

-04

Feb

-05

Feb

-06

Feb

-07

Date

Sta

ge

Hei

gh

t

r_412067

r_412002

r_412057

r_412004

r_412036

r_412006

r_412011



APPENDIX 5: Monitoring bore locations and model layer boundaries

Upper Cowra model boundaries and bore locations


400000 420000 440000 460000 480000 500000 520000 540000 560000 580000 600000 620000 640000 660000 6800006160000

6180000

6200000

6220000

6240000

6260000

6280000

6300000

6320000

6340000

6360000

6380000

GW036174_1GW036176_1

GW036502_1

GW036524_1

GW036528_1GW036554_1

GW036563_1

GW036594_1

GW021304_1GW021305_1GW021306_1GW021307_1

GW025030_1GW025103_1

GW025151_1GW025155_2GW025163_1

GW025166_1GW025167_2GW025168_1

GW030312_1GW030313_2GW030315_1

GW030365_1

GW030368_1

GW030371_1

GW030388_1

GW030467_1

GW030484_1

GW030486_1GW030487_1GW030488_1

GW030495_1GW036028_1

GW036030_1

GW036080_1

GW036082_1GW036083_1


Lower Cowra model boundaries and bore locations

400000 420000 440000 460000 480000 500000 520000 540000 560000 580000 600000 620000 640000 660000 6800006160000

6180000

6200000

6220000

6240000

6260000

6280000

6300000

6320000

6340000

6360000

6380000

GW030252_1GW030270_1

GW036089_1

GW036091_1

GW036174_2GW036175_1

GW036176_2

GW036177_1

GW036487_1

GW036500_1

GW036501_2

GW036502_2GW036522_2

GW036523_2

GW036527_1GW036528_3

GW036550_2

GW036551_2GW036552_2GW036554_3

GW036594_2

GW036595_1GW036596_2GW036597_1

GW036603_1GW036605_1

GW036610_1GW036613_1

GW036629_1

GW036700_1

GW036738_1GW036739_1

GW036741_1GW036776_1GW036777_2

GW036779_1

GW039379_1

GW014737_1

GW021165_1GW021301_1GW021302_1

GW021303_2GW021304_2

GW021305_2GW021306_2GW021307_2

GW025030_2GW025067_1GW025081_1GW025082_2

GW025102_1

GW025151_2GW025164_2GW025165_2

GW030247_1GW030249_1

GW030296_3

GW030314_1

GW030359_1

GW030361_1

GW030366_1GW030367_1

GW030369_1

GW030372_1GW030373_1

GW030374_1GW030376_1

GW030377_2

GW030482_1GW030483_2

GW030484_3

GW030485_3

GW030495_2

GW036029_2GW036030_2

GW036031_3

GW036079_1GW036080_2GW036081_1

GW036082_3

GW036083_3

GW036085_1

GW036086_1

GW036087_1



400000 420000 440000 460000 480000 500000 520000 540000 560000 580000 600000 620000 640000 660000 6800006160000

6180000

6200000

6220000

6240000

6260000

6280000

6300000

6320000

6340000

6360000

6380000

GW036088_2GW036089_2GW036090_2

GW036171_2GW036174_3GW036175_3

GW036487_3

GW036500_2

GW036502_3

GW036523_3

GW036526_2

GW036527_4

GW036550_3

GW036552_3

GW036553_1

GW036597_2

GW036604_1GW036606_1

GW036609_1

GW036611_1

GW036627_1

GW036632_1

GW036741_3GW036777_3

GW036779_2

GW039378_1

GW021165_2

GW025030_3GW025067_2

GW025151_3GW025155_3GW025164_4GW025165_3

GW030246_2GW030247_2GW030248_1GW030249_3GW030314_2GW030315_2

GW030359_3

GW030365_2GW030367_2

GW030368_2GW030369_2

GW030370_2

GW030372_3GW030373_4

GW030374_3

GW030377_4

GW030388_2

GW030483_4

GW030484_5

GW030485_4

GW036079_5GW036080_3GW036081_3

GW036087_3

Lachlan Formation model boundaries and bore locations




APPENDIX 6: Observed and simulated water level hydrographs

Figure 6-1 Comparison between simulated and observed water levels in layer 1 in Zone 6 (m) (AHD

30365

30368

30315

L1_Z6

0 2000 4000 6000 8000Time (days)

300

301

302

303

304

305

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000Time (days)

270

272

274

276

278

280

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

266

268

270

272

274

276

278

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

256

258

260

262

264

266

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

264

266

268

270

272

274

276

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

30371

30388

++++ Observed------- calibration



Figure 6-2 Comparison between simulated and observed water levels in layer 1 in Zone 2 & 3 (m) (AHD

30312_1

36502_130484_1

30495_1

L1_Zone(2&3)

0 2000 4000 6000 8000Time (days)

254

256

258

260

262

264

266

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

256

258

260

262

264

266

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

232

236

240

244

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

224

228

232

236

240

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

230

232

234

236

238

240

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

230

232

234

236

238

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

30467_1

30313_2

++++ Observed------- Model




30487_1

30486_136028_1

30495_1

L1_Zone(3)

0 2000 4000 6000 8000Time (days)

228

230

232

234

236

238

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

228

230

232

234

236

238

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

226

228

230

232

234

236

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

224

226

228

230

232

234

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

220

222

224

226

228

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

230

232

234

236

238

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36030 _1

30488_1

++++ Observed------- Model------- P mdl




36082_1

36083_1 36554_1

25168_1

L1_Zone(5)

0 2000 4000 6000 8000Time (days)

208

212

216

220

224

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

208

210

212

214

216

218

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

204

208

212

216

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

202

204

206

208

210

212

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

203

204

205

206

207

208

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

196

198

200

202

204

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36528_1

36080_1





25166_1

36563_1 25151_1

L1_Zone(5)_Part(2)

0 2000 4000 6000 8000Time (days)

196

198

200

202

204

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

196

198

200

202

204

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

198

200

202

204

206

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

192

194

196

198

200

202Ja

n-88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

192

194

196

198

200

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

25155_2

25167_2





25030_1

21307_130484_1

L1_Zone(5)_Part(3)

0 2000 4000 6000 8000Time (days)

184

186

188

190

192

194

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

184

186

188

190

192

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

181

182

183

184

185

186

187

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

224

228

232

236

240Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

25103_1





36524_1

L1_Zone(7)

0 2000 4000 6000 8000

198

200

202

204

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

198

199

200

201

202

203

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36594 _1





21305_1

21306_1

36176_1

L1_Zone(8)

0 2000 4000 6000 8000Time (days)

181

182

183

184

185

186

187

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

181

182

183

184

185

186

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

182

183

184

185

186

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

159

160

161

162

163

164Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

158

159

160

161

162

163

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36174 _1

21304_1





36500_1

30367_1

36501_2

30359_1

L2_Zone(2)_Part(1)

0 2000 4000 6000 8000Time (days)

270

272

274

276

278

280

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

260

264

268

272

276

280

284

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

266

268

270

272

274

276

278

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

260

264

268

272

276

280Ja

n-88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

266

268

270

272

274

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

256

260

264

268

272

276

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

30369_1

30366_1





14737_1

30296_3

30247_1

30361_1

L2_Zone(2)_Part(2)

0 2000 4000 6000 8000Time (days)

252

256

260

264

268

272

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

264

266

268

270

272

274

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

263

264

265

266

267

268

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

252

256

260

264

268Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

256

258

260

262

264

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

256

258

260

262

264

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

30314_1

30249_1




Figure 6-11 Comparison between simulated and observed water levels in layer 2 in Zone 2&3 (m) (AHD

36487_1

30373_1 30374_1

30377_2

L2_Z(2&3)

0 2000 4000 6000 8000Time (days)

252

254

256

258

260

He

ad

(m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

250

252

254

256

258

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

250

252

254

256

258

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

240

244

248

252

256Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

240

242

244

246

248

250

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

228

232

236

240

244

248

252

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

30376 _1

30372_1





36502_2

30484_330482_1

30495_2

L2_Zone(3)_Part(1)

0 2000 4000 6000 8000Time (days)

220

225

230

235

240

245

Hea

d (m

AH

D)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

220

224

228

232

236

240

244

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

216

220

224

228

232

236

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

228

232

236

240Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

200

210

220

230

240

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

228

230

232

234

236

238

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

30485_3

30483_2





36030_2

36031_336522_2

36079_1

L2_Zone(3)_Part(2)

0 2000 4000 6000 8000Time (days)

218

220

222

224

226

228

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

220

222

224

226

228

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

216

218

220

222

224

226

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

216

218

220

222

224

226

228Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

216

220

224

228

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

214

216

218

220

222

224

226

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36527_1

36029_2





36082_3

36081_1 36083_3

36085_1

L2_Zone(5)_Part(1)

0 2000 4000 6000 8000Time (days)

208

212

216

220

224

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

208

210

212

214

216

218

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

204

208

212

216

220

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

204

208

212

216Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

200

202

204

206

208

210

212

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

202

204

206

208

210

212

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36554_3

36080_2

++++ Observed------- Model------- P Mdl




36523_2

36552_236089_1

36551_2

L2_Zone(5)_Part(2)

0 2000 4000 6000 8000Time (days)

202

204

206

208

210

212

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

196

200

204

208

212

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

192

196

200

204

208

212

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

196

198

200

202

204

206

208Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

196

198

200

202

204

206

208

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

188

192

196

200

204

208

212

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36087_1

36086_1





36550_2

25165_2 25164_2

36091_1

L2_Zone(5)_Part(3)

0 2000 4000 6000 8000Time (days)

188

192

196

200

204

208

212

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

196

198

200

202

204

206

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

184

188

192

196

200

204

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

180

184

188

192

196

200

204Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

194

196

198

200

202

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

192

193

194

195

196

197

198

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

25151_2

36528_3





25030_2

25067_125081_1

L2_Zone(5)_Part(4)

0 2000 4000 6000 8000Time (days)

182

184

186

188

190

192

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

184

186

188

190

192

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

184

185

186

187

188

189

190

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

184

186

188

190

192Ja

n-8

8

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

176

180

184

188

192

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

25082_2

25102_1





36738_1

36739_1

L2_Zone(7)_Part(1)

0 2000 4000 6000 8000 10000Time (days)

228

232

236

240

244

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

244

248

252

256

260

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

268

272

276

280

284

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

36779_1


0 2000 4000 6000 8000Time (days)

256

260

264

268

272

276

280

Hea

d (m

AH

D)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

196

200

204

208

212

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

36777_2

30252_1

0 2000 4000 6000 8000

224

228

232

236

240

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

36741_1




39379_1

36603_136605_1

36596_2

L2_Zone(7)_Part(3)

0 2000 4000 6000 8000Time (days)

204

206

208

210

212

214

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

188

192

196

200

204

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

196

197

198

199

200

201

202

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

184

188

192

196

200

204Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

196

197

198

199

200

201

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

160

170

180

190

200

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

36700_1

36629_1





36595_1

36597_136613_1

L2_Zone(7)_Part(4)

0 2000 4000 6000 8000Time (days)

184

188

192

196

200

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

196

197

198

199

200

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

150

160

170

180

190

200

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

196

197

198

199

200Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

196

198

200

202

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36594_2

36610_1


0 2000 4000 6000 8000

200

204

208

212

216

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

30270_1




21302_1

21303_221304_2

21306_2

L2_Zone(8)_Part(1)

0 2000 4000 6000 8000Time (days)

178

180

182

184

186

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

172

176

180

184

188

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

172

176

180

184

188

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

180

182

184

186Ja

n-8

8

Jan-9

0

Jan-9

2

Jan-9

4

Jan-9

6

Jan-9

8

Jan-0

0

Jan-0

2

Jan-0

4

Jan-0

6

Jan-0

8

0 2000 4000 6000 8000

180

181

182

183

184

185

186

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

181

182

183

184

185

186

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

21305_2

21301_1





21165_1

36175_1 36176_2

36177_1

L2_Zone(8)_Part(2)

0 2000 4000 6000 8000Time (days)

178

180

182

184

186

Hea

d (m

AH

D)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

176

178

180

182

184

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

160

162

164

166

168

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

159

160

161

162

163

164Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

158

159

160

161

162

163

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

148

150

152

154

156

158

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

36174_2

21307_2





30365_2

36500_230367_2

30369_2

L3_Zone(2)_Part(1)

0 2000 4000 6000 8000Time (days)

300

301

302

303

304

305

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

268

272

276

280

284

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

255

260

265

270

275

280

285

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

264

268

272

276

280

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

266

268

270

272

274

276

278

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

266

268

270

272

274

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

30368_2

30388_2





30359_3

30315_2

30249_3

30247_2

L3_Zone(2)_Part(2)

0 2000 4000 6000 8000Time (days)

260

264

268

272

276

Hea

d (m

AH

D)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

252

256

260

264

268

272

276

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

256

260

264

268

272

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

245

250

255

260

265

270Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

248

252

256

260

264

268

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

240

245

250

255

260

265

270

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

30248_1

30370_2





30314_2

30372_3

36487_3

30374_3

L3_Zone(2)_Part(3)

0 2000 4000 6000 8000Time (days)

240

245

250

255

260

265

270

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

248

252

256

260

264

268

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

252

254

256

258

260

262

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

244

248

252

256

260Ja

n-88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

244

248

252

256

260

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

230

235

240

245

250

255

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

30373_4

30246_2





30483_4

36502_330484_5

36527_4

L3_Zone(2)_Part(4)

0 2000 4000 6000 8000Time (days)

220

230

240

250

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

200

210

220

230

240

250

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

200

210

220

230

240

250

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

200

210

220

230

240

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

200

210

220

230

240

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

190

200

210

220

230

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

30485_4

30377_4





36080_3

36081_3

36523_3

36526_2

L3_Zone(5)_Part(1)

0 2000 4000 6000 8000Time (days)

190

200

210

220

230

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

204

208

212

216

220

224

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

200

204

208

212

216

220

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

180

185

190

195

200

205

210Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

185

190

195

200

205

210

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

196

200

204

208

212

216

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36552_3

36079_5





36087_3

36088_236550_3

25165_3

L3_Zone(5)_Part(2)

0 2000 4000 6000 8000Time (days)

188

192

196

200

204

208

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

188

192

196

200

204

208

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

188

192

196

200

204

208

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

196

198

200

202

204

206Ja

n-88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

170

180

190

200

210

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

160

170

180

190

200

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

36090_2

36089_2





25151_3

25155_325067_2

L3_Zone(5)_Part(3)

0 2000 4000 6000 8000Time (days)

190

192

194

196

198

200

202

He

ad (

m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000 10000Time (days)

175

180

185

190

195

200

205

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

188

192

196

200

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

150

160

170

180

190Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

168

172

176

180

184

188

192

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

25030_3

25164_4





36777_3

39378_1

36741_3

L3_Zone(7)_Part(1)

0 2000 4000 6000 8000Time (days)

268

272

276

280

284

He

ad

(m A

HD

)

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

260

264

268

272

276

280

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

196

200

204

208

212

216Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

170

180

190

200

210

220

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

212

216

220

224

228

232

236

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36632_1

36779_2++++ Observed------- Model------- P Mdl




36627_1

36604_136611_1

36609_1

L3_Zone(7)_Part(2)

0 2000 4000 6000 8000Time (days)

192

196

200

204

208

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

185

190

195

200

205

210

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

188

192

196

200

204

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

150

160

170

180

190

200Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

150

160

170

180

190

200

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

140

160

180

200

220

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

36597_2

36606_1




36175_3

36174_3

36553_1(Zone7)

L3_Zone(8)

0 2000 4000 6000 8000Time (days)

176

178

180

182

184

He

ad (

m A

HD

)

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000 10000Time (days)

158

160

162

164

166

Jan-

88

Jan-

90

Jan-

92

Jan-

94

Jan-

96

Jan-

98

Jan-

00

Jan-

02

Jan-

04

Jan-

06

Jan-

08

0 2000 4000 6000 8000

158

159

160

161

162

163

Jan

-88

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

0 2000 4000 6000 8000

140

160

180

200

220Ja

n-8

8

Jan

-90

Jan

-92

Jan

-94

Jan

-96

Jan

-98

Jan

-00

Jan

-02

Jan

-04

Jan

-06

Jan

-08

21165_2

++++ Observed------- Model------- PMdl


upper lachlan groundwater flow model · 2018. 4. 23. · figure 2-5 residual mass curve of rainfall...

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