page 1© crown copyright 2004 meteorological inputs groundwater workshop, birmingham murray dale,...

© Crown copyright 2004

Meteorological Inputs

Groundwater Workshop, BirminghamMurray Dale, 4/11/04


Presentation Content

Rainfall Data

MORECS & MOSES


Rain Gauge Network

Real time Daily - 200 Real time Hourly - 175 (1000 planned) Slow time Daily - 3500 Slow time hourly - 200


Quality Control

QA team based in Edinburgh, lead by Ross Melville and Derek Ogle

Brochure availableConforms to British Standard BS7834 (1996) – Guide to the acquisition and management of meteorological precipitation data (establishing a network, user requirement, siting, data management, QA…)


UK Radar Coverage

1 km coverage(50 km range)




Rain gauge location(and 1km storm accumulation)

0 10 20 30 40 50 60 70 80 90 100 mm


1km radar accuracy (1 of 3)

Woodford 5-minute rainfall data on 31/12/03, aggregated to 15-minute totals

0.00

0.50

1.00

1.50

2.00

2.50

21:00:00 21:15:00 21:30:00 21:45:00 22:00:00 22:15:00 22:30:00 22:45:00 23:00:00 23:15:00 23:30:00 23:45:00 00:00:00

Ra

infa

ll (

mm

)

raingauge

Hameldon Hill radar

Rainfall totals:Radar: 14.5mmRaingauge: 12.2mm



Shawbury 5-minute rainfall data on 28/8/03, aggregated to 15-minute totals

0.00

0.20

0.40

0.60

0.80

1.00

1.20

07:3

008

:00

08:3

009

:00

09:3

010

:00

10:3

011

:00

11:3

012

:00

12:3

013

:00

13:3

014

:00

14:3

015

:00

15:3

016

:00

16:3

017

:00

17:3

018

:00

Rai

nfa

ll (m

m)

Raingauge

Clee Hill radar

Rainfall total:Radar: 12.1mmRaingauge: 12.6mm



Dunkeswell 5-minute rainfall data on 1/12/03, aggregated to 15-minute totals

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

09:0

0:00

09:1

5:00

09:3

0:00

09:4

5:00

10:0

0:00

10:1

5:00

10:3

0:00

10:4

5:00

11:0

0:00

11:1

5:00

11:3

0:00

11:4

5:00

12:0

0:00

12:1

5:00

12:3

0:00

12:4

5:00

13:0

0:00

13:1

5:00

13:3

0:00

13:4

5:00

14:0

0:00

14:1

5:00

14:3

0:00

14:4

5:00

15:0

0:00

15:1

5:00

15:3

0:00

15:4

5:00

16:0

0:00

16:1

5:00

16:3

0:00

16:4

5:00

17:0

0:00

Rai

nfa

ll (m

m)

raingauge

Cobbacombe radar

Rainfall totals:Radar: 23.6mmRaingauge: 15.8mm


Radar / Gauge data in Urban Drainage Modelling

RainObs.

...ay 2 f inal>Wet Day 2...ROD_NEC_Ev ent02

Rainf all

Depth (mm)

6.000

Peak (mm/hr)

6.000

Av erage(mm/hr)

0.744

Depth (m)

Min

0.2800.2190.232

Max

1.4360.5910.652

Flow (m3/s)

Min

0.0180.0210.028

Max

0.3550.2690.305

Volume (m3)

3831.9003361.2773943.132

Velocity (m/s)

Min

0.1500.3670.417

Max

1.5001.2461.403


MORECS


MOSES

Soil Moisture data derived from radar Advanced scientific representation of

processes 5km spatial resolution Hourly updated Provides information on soil moisture status


MOSES

Soil moisture deficit from MOSES

Darcian flow of soil moisture

Deep drainage

Surface runoff

Evaporation frombare soil, trees,grass, crops,wet canopies etc.

Rain,Snow Radiation

Rootsextractwater


Moses detail reference on-line

http://www.metoffice.gov.uk/research/nwp/publications/papers/technical_reports/fr.html

Report # 428


MOSES-PDM – MORECS Inter-comparison

Project jointly funded by the EA and Met OfficeCompared two extreme hydrological events

Drought of 1975-76 and floods of 2000-01For 4 contrasting MORECS squares24 month periods investigated

Inter-comparison contrasted with findings from available literature

Study concluded that MOSES-PDM better represents processes of evaporation, drainage and soil moisture than MORECS


A comparison of SMD for grass from MORECS, MOSES-PDM and observations at one site from 1995-1997. (Redrawn from Blyth

(2002))

0

20

40

60

80

100

120

140

160

Jan-9

5

Mar-9

5

May-

95

Jul-9

5

Sep-95

Nov-95

Jan-9

6

Mar-9

6

May-

96

Jul-9

6

Sep-96

Nov-96

Jan-9

7

Mar-9

7

May-

97

Jul-9

7

Sep-97

Nov-97

Date

SM

D (

mm

)

MORECS MOSES-PDM OBSERVATIONS


Variable Difference from comparison

Period Support from literature review?

Possible causes

PE/AE MX>MS Winter MOSES canopy resistance, soil heat flux

Annual √

PE MX>MS Very dry summer MOSES canopy resistance

AE MX=0, MS>0 Very dry summer √ Fixed available water in MORECS, MOSES calculates water transfer in dry soil

EP MX>MS Autumn √ In MOSES the gradual wetting of the lowest soil layer gives a slower onset of drainage

EP MX<MS Summer, annual √ MOSES has less AE and also has

drainage when SMD>0

SMD MX>MS Spring √ MORECS has more AE

MOSES / MORECS Comparison Summary


Inter-comparison

MORECS uses the science and concepts of the late 1970s; the update in 1995 introduced more realistic soils data, but did nothing to change the basic science. MOSES includes more recent developments in evaporation and soils modelling including: Canopy resistance to moisture transfer which interacts with

weather Soil heat flux modelling Soil moisture movement modelling, snowmelt, surface runoff 5 km soils and land use, but only 1 farm crop type PDM represents a range of soil properties to represent soil

moisture variability and runoffThis report has shown the benefits of these

improvements


Summary

Raingauge network details, planned real-time gauge increase, QC obligations

Radar – more appropriate for spatial rainfall than point source data (gauges)

MORECS – 1970s model, modifications in 1990s

MOSES – higher resolution (time and space), better representation of reality

page 1© crown copyright 2004 meteorological inputs groundwater workshop, birmingham murray dale,...

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