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

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

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

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

Sources of Data HUC and RF1 coverage's for the region (scale 1:250,000) ftp://water.usgs.gov/pub/dsdl/ http://water.usgs.gov/GIS/metadata/usgswrd/erf1.html National Elevation dataset DEM grid obtained from http://seamless.usgs.gov/ or Bear river watershed http://water.usu.edu/wis/bearriver Soil Data-STATSGO (State Soil Database) http://www.ncgc.nrcs.usda.gov/branch/ssb/products/statsgo/index.html

Bear River Watershed HUC 16 RF1

Importing DEM data into ArcGIS format

Contours using Spatial Analyst

Delineated Stream Network

Watersheds Delineation

Top Model Parameter Lambda

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

Selected Monitoring Points