1. Modeling Source-water Contributions to Streamflow
along a Stream-Lake-Stream Couplet in a Mountain Watershed
Christopher D. Arp
Dept. of Biology and The Ecology Center
Utah State University
GIS in Water Resources term project - November 2002

2. understanding and predicting how linkages between lakes and
streams effect aquatic ecosystem structure and function
My Research: hydrologic controls on N cycling
hillslope-to-stream scale
stream-reach scale
watershed scale TOPMODEL GISWR termproject

3. Watershed Hydrology
(TOPMODEL)
source-water volumes [V]
Mixing Model
CTVT = CsurfVsurf + CsoilVsoil + CgwVgw
surface runoff (surf)
soil water (soil)
groundwater (gw)
soil water
groundwater
Nitrogen Flux
surface runoff
Watershed Chemistry
(endmember sampling)
source-water concentrations [C]
Time
Goals
Understanding: watershed processes and stream biogeochemistry
Application: land-use, aquatic ecosystems, & water quality

4. TERM PROJECT OBJECTIVES
Review of TOPMODEL applications for hydrochemical modeling
Acquire necessary data (input & validation)
Prepare DEM using TauDEM
Analysis of study catchments using tools in ArcGIS & TauDEM

7. INPUT DATA (spatial) Topography & Hydrography Soils (porosity)
Digital Elevation Model (DEM) – 30 m
USGS National Elevation Dataset
Drainage Network
National Hydrography Dataset
Soils (porosity)
County Soils Database (SSURGO) – NO DICE!
State Soils Database (STATGO) – 1:250,000 NG!

8. INPUT DATA (climate) Temperature (daily) Rainfall &
on-site weather station (~ 2130 m)
Rainfall &
Snow Water Equivalents (daily)
NRCS SNOTEL STATION
(Banner Summit – 312)
.pl?sitenum=312&state=id
Proximity: N44.30, W (~2150 m)

9. VALIDATION & CALIBRATION DATA
(streamflow)

10. DEM PROCESSING STEPS Project DEM & NHD datasets – UTM zone 11
Fill Pits, D8 & Dinf Directions, & Contributing Areas
River Network Delineation
Compare NHD network to DEM generated network,
edit channel network and “burn-in” new network
Stream delineation and constant drop test
Add catchment outlets
Delineate catchments and subbasins
Calculate wetness index and flow path lengths

11. Network Discrepancy
Edited Network

12. Raw Spatial Data
TOPsetup Ready

15. What Next? Get soils data Determine which version of TOPMODEL
is best for this application
Run TOPsetup
(if Tarboton version of TOPMODEL is selected)
Determine appropriate submodels
for ET and snowmelt
5. Run TOPMODEL and compare results
to empirical Q data
6. Etc, Etc, Etc