application of gis techniques in regional hydrology

Application of GIS Techniques in Regional Hydrology and Watershed Planning

Chris Propp, P.Eng

CWRA March, 2011

March 9th, 2011

PRESENTATION THESIS

• Geographic Information Systems (GIS) tools facilitate the collection, management, display and analysis of geographic information useful in regional hydrologic analysis and watershed planning

• Benefits include:– Increased Efficiency of Hydrologic Analysis

– More Comprehensive Watershed Planning Capacity

March 2, 2011GIS in Hydrology and Watershed Planning

OUTLINE

• Hydrologic Analysis– Watershed Delineation

– Watershed Characteristics

– Hydrologic Analysis Example

– Benefits of GIS-Based Hydrologic Analysis

• Watershed Planning Project Examples• Watershed Planning Project Examples– Impact of Watershed Development

– Flood Zone Analysis


GIS IN HYDROLOGY AND WATERSHED PLANNING

• Hydrologic Analysis is most commonly required to estimate design flow

• GIS analysis can aid in identifying hydrologic parameters affecting runoff and design flows


BENEFITS OF GIS-BASED HYDROLOGIC ANALYSIS

• Multiple Site Studies

• Increased Efficiency for:– Catchment data collection

– Spatial analysis

– Digital image distribution & communication with regional representativesrepresentatives

• Better Understanding of Hydrologic System– Cost savings + more product for $$


DETAILED LAND USE DATA AVAILABLE ONLINE (MLI)


DETAILED SOIL CLASSIFICATION DATA AVAILABLE ONLINE (MLI)


ANALYSIS EXAMPLE

Example Site #948


EXAMPLE AREA

Culvert site


Catchment #

CATCHMENT TOPOGRAPHY AND GEOMETRY

L:W ratio


CatchmentSlope = 0.22%

CATCHMENT ANALYSIS – LAND USE

Wet lands

Agriculture

Forage


Woody Vegetation

CATCHMENT ANALYSIS – STORAGE %


27% Wetland Storage at Mid Catchment

ANALYSIS EXAMPLE


0.8

ANALYSIS EXAMPLE


1.2

0.8

1.11.00.9

Lake Winnipeg

WATERSHED DELINEATION BY HEC-GEOHMS & LIDAR


Demonstration region


• Level 1 text 24pt Arial

– Level 2 bullet 20pt Arial

• Level 1 text 24pt Arial

• Level 2 bullet 20pt Arial

• Initial Grid

– Pixelizedelevation data

– Streams added for clarity

March 2, 2011Presentation Title

clarity


• Fill Grid

– Stream is burned into elevation model



• Flow Grid

– Shows direction of raindrop flow



• Sub-catchments

– Dark shades are higher elevation than light




• West FisherSub-catchments

– Manual delineation of watersheds shown for comparison

FISHER RIVER STUDY AREA GIS DATA & FIELD SURVEY

Dallas

Koostatak

Fisher River

HodgsonPeguis

348 crossings 312 culverts 34 bridges 22 fords

Lake Wpg


Fisher Branch

PR325

FISHER RIVER BASIN

Total Area 2300 km2

Gross vs. Effective Area

North 37% Ineffective


East 11% Ineffective

West 49% Ineffective

WATERSHED PLANNING PROJECT EXAMPLE – LAND USE


IMPACT OF WATERSHED DEVELOPMENT


Land Use Data -1966 – 5 classes



Land Use Data -1966 – 5 classesLand Use Data – 2002 – 16 classes



Land Use Data – 2002 – 16 classes merged to 5


AECOM AnalysisAECOM


Land Use as Five Classes

7

43

6

8

DRAINAGE NETWORK CHANGE

2006 Network -

1966 Network -Red

12

5

43


2006 Network -Blue

1966 - No main stem network defined

IMPACTS OF LAND USE AND DRAINAGE CHANGE –FLOW & LEVEL INCREASE

Q: 27%WL: 0.08m (3 in)

Q: 5%WL: 0.03m (1 in)

Q: 6%WL: 0.05m (2 in)

Q: 3%WL: 0.03m (1 in)

Q: 1%WL: 0.0m


Q: 12%WL: 0.5m (19 in)

Q: 595%WL: 0.6m (22 in)

Q: 8%WL: 0.09m (4 in)

Q: 7%WL: 0.08m (3 in)

WL: 0.03m (1 in)

100yr Flood Map with 2006

Flood

Modelled water levels overlain with detailed LiDAR

topography

100 Yr Flood

2006 Flood

GIS IN WATERSHED PLANNING – FLOOD ZONE ANALYSIS


topography

Fisher River 1979 (123cms) Flood Damage Claims Map

MIKE11 Fisher River 100Year Flooded Area Map



Fisher River Dike Option GIS used to identify affected homes



Alternative Diversion Routes

Eagle Nest Drain




Alternate Diversion RouteLiDAR Section cut through the Eagle


through the Eagle Nest Drain surface


100yr Flood Map with Diversion Option


HYDRAULIC LEVEL OF SERVICE ANALYSIS

Culverts Green dotsBridge Blue Triangles

Culvert & Bridge Level of Service Analysis - 2 Yr flow



Culvert & Bridge Level of Service Analysis - 5 Yr flow


Culverts HL > 0.21m Yellow dots




Culverts HL > 0.21m Yellow dots

Culvert & Bridge Level of Service Analysis - 10Yr flow


FLOOD ZONE ANALYSIS – EXAMPLE 2


Local Flood History


Existing Condition – 10 Year Flooded Area

Blue shows 10 Year Flooding under existing conditions



10 Year Flooded Area – with Fourth Creek Diversion

Green shows flooded area after diversion


Blue shows reduction in 10 Yr Flooding, or the benefit of mitigation

WATERSHED PLANNING – DFO STREAM CLASSIFICATION


CONCLUSION

GIS-Based Hydrology and Watershed Planning

• Multiple site studies

• Aids catchment data collection and spatial analysis

• Provides empirical justification of hydrologic analysis assumptions

• Infrastructure inventory management

• Bird’s eye view of watershed system


• Bird’s eye view of watershed system– Impact of development

– Analysis of flood zone mitigation

• Graphical representation provides for effective communication with clients and stakeholders

Thank You

Questions?

application of gis techniques in regional hydrology

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