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.  Progress Report: Figured out what to do with.avx file and Hydro1k data.  Final Report: Determined linkage between the GIS and rainfall-runoff simulation model; and successful at using 60% of model’s capabilities

The FEWS Stream Flow Model  Spatially-lumped continuous soil moisture accounting model  Inputs (all grids) include Hydro1K, NOAA estimates of daily rainfall totals, USGS land use/land cover dataset, and FAO soils layer  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

Exploring the Components of the FEWS SF Model in ArcView  Fewsflood.avx added to EXT32 ArcView folder Route.exe added to the BIN32 ArcView folder  Text files supplied are organized by level 5 Pfafstetter codes  These included basin.txt, evap.txt, parameter.txt, rain.txt and response.txt  Run route.exe

route.exe

Data Collection- Hydro1K Hydro1K

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  No information on model units, used text files instead (recycling data)

Hydro1K Preparation (DEM) Match Hydro1K Pfafstetter Level 5 Basins

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

GRIDS

Running the FEWS SF Model !!!!!

Complete Terrain Analysis  User supplies DEM  FEWS SF Model creates missing grids and shapefiles (Downstream Grid, Hill Slope Grid, Hill Length Grid, Basins Grid, basply.shp, Outlets Grid, StrLinks, Streams, FlowLen, FlowAcc, and FlowDir  Final threshold chosen to be 3,000 cells

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  OUTPUT: basin.txt

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

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

Perform Flow Routing  INPUT:

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

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

Compute Rain/Evap Statistics Con’t  OUTPUT:

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

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

CONCLUSIONS  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!

SPECIAL THANKS  Gulied A. Artan  Jordan Furnans