WEPP Update PWRA

The Water Erosion Prediction Project (WEPP) Modeling

Description

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The Water Erosion Prediction Project (WEPP) model is a resource used by the scientific and emergency management community to predict hillslope erosion of small watersheds post-wildfire. This process-based system aids in identifying vulnerable to improve land use and treatment plans by the responsible parties.

Duration: 1-3 days

The typical duration of the WEPP is three days depending on the size of the fire. It can take as little as 24 hours with streamlined data.

Responsible Resources

Rocky Mountain Research Station, USDA Forest Service, and Agricultural Research Service (ARS) in Moscow, Idaho are involved in the process. Other supporting resources include USDA Forest Service, Agricultural Research Service (ARS) (West Lafayette, Indiana), Bureau of Land Management (BLM), Michigan Tech (provides the information databases to run the WEPP model), Army Corps of Engineers, National Erosion Lab, and Natural Resources Conservation Service (NRCS). The WEPP is a collaboration with a lot of interagency.

Triggers

The Forest Service Burned Area Emergency Response (BAER) Team may request assistance in running the WEPP model from researchers. For smaller fires, the BAER teams have the capability within the team to do most of the modeling and have been trained on the applications of the models.

?Predecessors

The Soil Burn Severity Map is necessary to run the WEPP.?

Input Requirements

1)?????Soil Burn Severity Map provided by GTAC

a.???????This data set includes climate, hillslope, and irrigation.

2)?????Climate data, topography data, soil condition data and rainfall data

3)?????land cover data modified by burn severity map

Product

The WEPP model produces various flow predictions maps that show spatial distribution of erosion. The products produced can be manipulated by BAER teams as needed. This data is critical for the initial assessment of the ground teams for data validation on the areas at risk of sedimentation hazards. Model data additionally produces It also creates erosion risk maps and runoff maps.

Issues/Other Considerations

1. The WEPP watershed process can occasionally crash, so the modeler needs to ensure that all areas within a burn are modeled and may need to fill in some areas manually.
2. It is important to keep SME in the loop with each other to help the flow of the process. By communicating with the modeler’s tasks can be achieved in a timely manner.
3. A need is seen for adapting existing products to meet the needs of specific components relating to community risk, like road stream crossing bridges and culverts, and water supply intake structures and treatment plants.?
4. All data partners are reliant on the BAER releasing data.?This has slowed processes and products.?Pre-agreement with the emergency management partners can eliminate this problem.

Water Erosion Prediction Project (WEPP) Spatial Mapping Products

Results of WEPP/GIS data have not historically been used for making decisions about temporary housing or long-term recovery projects but may be able to help influence future decisions made by FEMA in both Individual and Public assistance work projects. WEPP results can be useful for ensuring that culverts on roads accessing these temporary sites will not be washed out by flood flows, and that water supply systems will not be detrimentally impacted by excessive upland sediment delivery. WEPP uses soil burn severity map GIS data as input to compare pre-fire land cover and base-soil data to estimate the quantity of erosion during a storm.?WEPP erosion estimates can readily be made available to the public as maps, summary tables, or GIS files.

The following is an example of a GIS text box required for Water Erosion Prediction Project (WEPP) spatial mapping products:

WEPP (Water Erosion Prediction Project): Potential post-fire erosion rates predicted for hillslopes affected by fire using the NASA BAER rapid response online database to develop model inputs for GeoWEPP, the Geographical interface for WEPP (https://geodjango.mtri.org/geowepp/). The primary inputs for GeoWEPP include a digital elevation model (DEM), climate data, soil maps, and land cover/land management information. Fire affected land cover accounted for by Soil Burn Severity (BARC) maps initially provided by BLM and Calfire.

Table 3: Water Erosion Prediction Project (WEPP) Spatial Mapping Products (Watershed Clearinghouse FEMA-4240-DR-CA)

Table 3 represents the products produced for Water Erosion Prediction Project (WEPP) Spatial Mapping Products including name of the map, descriptions, naming conventions, and inputs. (Watershed Clearinghouse Data and Products_20151120.xlsx, Ethridge)

Predicted Erosion Rate

Description

This map depicts potential post-fire erosion rates predicted for hillslopes affected by fire using the NASA BAER rapid response online database to develop model inputs for GeoWEPP, the Geographical interface for Water Erosion Prediction Project (WEPP). The primary inputs for GeoWEPP include a digital elevation model (DEM), climate data, soil maps, and land cover/land management information. Fire affected Land cover accounted for by Soil Burn Severity (BARC) maps initially provided by BLM and Calfire.

Naming Convention

FireName_WEPP_erosion_Date

Input (Key Data Layers) WEPP, Gages, Dams, Culverts

Predicted Erosion Rate at Roadways

Description

Roadway Erosion Rate Areas 100 Feet from Roadways. Produced with WEPP (Water Erosion Prediction Project): Potential post-fire erosion rates predicted for hillslopes affected by fire using the NASA BAER rapid response online database to develop model inputs for GeoWEPP, the Geographical interface for WEPP. The primary inputs for GeoWEPP include a digital elevation model (DEM), climate data, soil maps, and land cover/land management information. Fire affected Land cover accounted for by Soil Burn Severity (BARC) maps initially provided by BLM and Calfire.

Naming Convention

FireName_Roadway_Erosion_20151117

Input (Key Data Layers) WEPP, Gages, Dams, Culverts