Application of the FEWS Stream Flow SF Model

Application of the FEWS Stream Flow (SF) Model to the Limpopo Basin, Mozambique Final Report Tanya Hoogerwerf

OVERVIEW Mid-Semester: Obtained the FEWS SF Model and text files, but no user information. Ø Progress Report: Figured out what to do with. avx file and Hydro 1 k data. Ø Final Report: Determined linkage between the GIS and rainfall-runoff simulation model; and successful at using 60% of model’s capabilities Ø

The FEWS Stream Flow Model Spatially-lumped continuous soil moisture accounting model Ø Inputs (all grids) include Hydro 1 K, NOAA estimates of daily rainfall totals, USGS land use/land cover dataset, and FAO soils layer Ø Gulied A. Artan of the USGS provided this model and text files that result when the model is applied to the Limpopo basin in Mozambique Ø

Exploring the Components of the FEWS SF Model in Arc. View Fewsflood. avx added to EXT 32 Arc. View folder Route. exe added to the BIN 32 Arc. View folder Ø Text files supplied are organized by level 5 Pfafstetter codes Ø These included basin. txt, evap. txt, parameter. txt, rain. txt and response. txt Ø Run route. exe Ø

route. exe

Data Collection- Hydro 1 K

Additional Datasets Need Derived Soils Properties files!!

Data Preparation The required grids for the FEWS SF Model are a DEM, CN grid, Soil Water Holding Capacity Grid, Hydraulic Conductivity Grid, Soil Depth Grid, Texture Grid, Precipitation Grid, Evaporation Grid and Velocity Coefficient Grid Ø No information on model units, used text files instead (recycling data) Ø

Hydro 1 K Preparation (DEM) Match Hydro 1 K Pfafstetter Level 5 Basins

Additional Grids Text files imported into Excel Ø Saved as a. dbf files Ø In Arc. View the fields were joined by Pfafstetter 5 digit codes Ø New field created Ø Shapefile converted to a grid Ø

GRIDS

Running the FEWS SF Model !!!!!

Complete Terrain Analysis User supplies DEM Ø FEWS SF Model creates missing grids and shapefiles (Downstream Grid, Hill Slope Grid, Hill Length Grid, Basins Grid, basply. shp, Outlets Grid, Str. Links, Streams, Flow. Len, Flow. Acc, and Flow. Dir Ø Final threshold chosen to be 3, 000 cells Ø

Generate Basin Characteristics File INPUT: Basins Grid, Elevations (DEM), Flow Accumulation Grid, Hill Length Grid, Hill Slope Grid, CN Grid, Water Holding Capacity Grid, Soil Depth Grid, Hydraulic Conductivity Grid, Downstream Flow Length Grid, Stream Link Grid, Downstream Grid, and Max Impervious Grid Ø OUTPUT: basin. txt Ø

Generate Basin Response File INPUT: Velocity Coefficient Grid, Basins Grid, Flow Direction Grid, Stream Outlet Grid Ø OUTPUT: response. txt Ø

Generate Rain/Evap Data Files INPUT: Basin Grid, Rain Grid and Evaporation (as rain_19991 and evap_19991) Ø Can extract rain, evaporation or both Ø OUTPUT: rain. txt and evap. txt Ø

Perform Flow Routing Ø INPUT:

Perform Flow Routing Continued Utilizes route. exe and previously created txt files Ø Errors!!! Ø

Compute Rain/Evap Statistics Ø INPUT: Ø Select statistic to be computed

Compute Rain/Evap Statistics Con’t Ø OUTPUT:

Compute Flow Statistics and Display Flow Percentile Map Ø INPUT: ? ? ? Ø Errors!!!

Display Flooded Area Map INPUT: Processed DEM, Stream Links Grid, Flow Accumulation Grid, flow depth (riverstage. txt), day Ø OUTPUT: Zone of Influence Grid and Flooded Area Grid Ø

CONCLUSIONS Ø Ø Still a few small flaws in the model With a simple set of instructions, could be easy to use Wide range of applicability for large basins Ready for a trip to MOZAMBIQUE! http: //mozambique. gecp. virginia. edu/Floods/mozapic 34. jpg

SPECIAL THANKS Gulied A. Artan Ø Jordan Furnans Ø