1. Application of TOPMODEL GIS for Bear River Watershed
GIS in Water Resources
Term paper Presentation
Khalil Ammar
November,23th,2004

2. Bear River Watershed
is located in northeastern Utah, southeastern Idaho, southwestern Wyoming
HUC 16
RF1

3. TOPMODEL
TOPMODEL is a set of conceptual tools used to reproduce the hydrological behavior of catchments in a distributed way.
Input data needed
Watershed area
DEM grid
Soil texture data- STATSGO data
Soil hydraulic properties
Output
mean water table depth

4. Local depth to the water table Z
TOPMODEL Assumptions
Saturated hydraulic conductivity decrease exponentially with depth
Saturated lateral flow driven by topographic gradients
Steady State
Local depth to the water table Z
Z’ : Spatial average of depth to water table
Wetness index : ln (a/tan beta)
Lambda : Spatial average of ln (a/tan beta)
f : assumed decrease of hydraulic conductivity with depth

5. Sources of Data
HUC and RF1 coverage's for the region (scale 1:250,000)
ftp://water.usgs.gov/pub/dsdl/
National Elevation dataset DEM grid obtained from or
Bear river watershed
Soil Data-STATSGO (State Soil Database)

6. Bear River Watershed
HUC 16
RF1

7. Importing DEM data into ArcGIS format

8. Contours using Spatial Analyst

9. Delineated Stream Network

10. Watersheds Delineation

12. Top Model Parameter Lambda

13. Future work (to be done)
TOPMODEL parameters
Soil texture
Hydraulic conductivity
Calculate depth to water table Z
Rainfall
Stream Flow
Calibrate/ compare results with monitored stream flow

14. Selected Monitoring Points