2010 Annual Report
1a.Objectives (from AD-416)
1) Integrate the WEPP and WEPS model erosion technologies through the use of the Object Modeling System (OMS) into a single wind/water erosion prediction system using common databases and interfaces at the plot and field scale..
2)Incorporate, test and verify new erosion science or related components, such as winter processes, tillage erosion, ephemeral gully erosion, irrigation erosion and rangeland erosion, into the integrated erosion prediction system..
3) Cooperate with all ARS scientists and NRCS staff involved with the CEAP effort to extract relevant modules from existing models such as SWAT (Soil and Water Assessment Tool), RUSLE2 (Revised Universal Soil Loss Equation – version 2), AnnAGNPS (Annualized AGricultural Non-Point Source pollution), CONCEPTS (CONservational Channel Evolution and Pollutant Transport System), WEPP (Water Erosion Prediction Project), WEPS (Wind Erosion Prediction System), and REMM (Riparian Ecosystem Management Model) and integrate them into the OMS for development of regional water and air quality models at the plot, field, and watershed scales.
1b.Approach (from AD-416)
Objective 1: a) Incorporate the core WEPP model erosion component into the Object Modeling System, test and verify against the original WEPP model. b) Develop a single storm hydrology and water erosion model in OMS, then adapt model in OMS to handle temporal (multiple storms) and spatial (multiple flow planes) looping. c) Develop a continuous simulation water erosion model in OMS containing infiltration, ET, percolation, water balance, surface runoff routing, and water erosion calculations (multiple storms and multiple spatial planes). d) Create a single event wind detachment component in OMS based upon the core WEPS erosion code. Test and verify against the original WEPS code. e) Create a single event combined wind and water erosion model in OMS, using the individual water and wind modules. f) Merge wind detachment component into continuous simulation OMS water erosion model. g) Add other required components needed for a complete prediction system, including climate generation, plant growth, tillage disturbance, residue management, baseline hydrologic, and erodibility parameterization, etc. h) Test, verify, and validate modules and models. i) Work with NRCS and other users on interface and database development.
Objective 2: a) Develop detailed guidelines and instructions for cooperators on formats needed for new components to be incorporated within OMS for inclusion in combined wind and water model, or as special model applications using existing modules from the combined model. b) Work with ARS and university cooperators on testing, verifying, and validating new component modules within OMS. c) Incorporate, test, and verify new erosion science or related components, such as winter processes, tillage erosion, ephemeral gully erosion, irrigation erosion and rangeland erosion, into the integrated erosion prediction system.
Objective 3: This effort is a part of the Conservation Effects Assessment Project (CEAP) Objective 5 which deals with development of regionalized watershed models for assessment of the impacts of field soil conservation practices on off-site resources (water, air, etc.). Hillslope and field components developed in Objectives 1 and 2 may be utilized within larger regionalized models. Alternately, due to much larger scale representations and more coarse process conceptualization, use of simpler types of erosion functions may also be warranted and necessary. CEAP-Objective 5 work is being led by staff in ASRU in Fort Collins, CO.
The initial linked WEPS-WEPP model prototype has been completed, and testing revealed inconsistencies in the predictions of runoff and water erosion by the linked code and the original WEPP model. ARS collaborators at the Engineering and Wind Erosion Research Unit in Manhattan, Kansas are investigating to determine the causes of the differences, and identify potential corrections needed. An updated version (v2010.1) of the WEPP model was released in January, 2010. This version includes enhancements and corrections, particularly related to simulation of freezing, thawing and melting processes. Testing with observed data from Pullman, WA and Morris, MN showed large improvements in prediction of cold season processes, making WEPP more applicable to colder regions and the Palouse area. The NRCS user requirements for erosion prediction, initially developed as part of the 2008 WWEM Meeting in Ft. Collins, CO, have been under review and revision by ARS erosion scientists. A modified set, as well as a revised draft letter from NRCS to ARS has been created. ARS-ASRU-Ft. Collins has written Java-based simulation modules (80+ representing water balance, infiltration, runoff, stream flow, erosion, nutrient cycling, plant growth, winter processes, and lateral flow and ground water movement) to form the AgroEcoSystem-Watershed (AgES-W) regionalized watershed model. Components from the European J2000, SWAT, WEPP, and APEX models were integrated under OMS. AgES-W allows for conjunctive stream flow and groundwater interaction, carried out by hydrological response units (HRUs) which are connected by a lateral routing scheme to simulate lateral water transport processes. Formal evaluation of AgES-W for stream flow was performed using data from the NSERL CEAP Cedar Creek Watershed in Indiana with work underway to evaluate the model for Cedar Creek nitrogen dynamics as well. An updated version (v3.0) of the Object Modeling System (OMS) at ARS-ASRU-Ft. Collins was released. The combined wind and water erosion model prototype that was developed under OMS version 2.2 is not currently functional under the newly updated OMS Version 3.0. Plans are for staff at ARS-ASRU-Ft. Collins to incorporate the WWEM prototype into OMS v3.0 later this year. The project is collaborating with the USDA-Forest Service on a grant project to develop a web-based geo-spatial WEPP interface for forest watershed erosion predictions in the Great Lakes Basin (funded by U.S. Army Corps of Engineers). In FY10, the existing WEPP web-based GIS interface was ported to a web server managed by project collaborators at Washington State University (WSU). They are enhancing and tailoring the new system for Great Lakes forested watersheds, and expect to have an operational prototype later in 2010. The project is also collaborating with faculty at both WSU and the University of Iowa on simulation of larger channel flows and erosion processes linked with the existing WEPP model. Additionally, there is potential interest by USEPA and TetraTech on utilizing portions of the WEPP model science/code to better simulate sediment losses from pervious areas in urban landscapes.
Release of updated WEPP model version 2010.1 in January 2010. WEPP model version 2010.1 contains significant improvements in the prediction of soil freezing and thawing, as well as snow accumulation and runoff resulting from snow melting. Cooperative work between ARS-NSERL, ARS-Pullman, and Washington State University resulted in this updated version. The new model version performs much better in validation studies using data from Pullman, WA and Morris, MN. Additionally, some other important corrections were made to the code that fixed problems related to soil layer representation and multiple flow element erosion simulation. This model release impacts the thousands of WEPP model users throughout the U.S. and world, and will provide better predictions of runoff, soil loss and sediment yield from hillslope profiles and small field-scale watersheds. Users in areas experiencing substantial erosion from snowmelt on thawing soils should notice particularly better performance.
Duran Zuazo, V.H., Rodriguez Pleguezuel, C.R., Flanagan, D.C., Raya, A.M., Francia Martinez, J.R. 2009. Agricultural Runoff: New Research Trends. In: Hudspeth, C.A., Reeve, T.E., editors. Agricultural Runoff, Coastal Engineering and Flooding. Hauppauge, New York. Nova Science Publishers. p. 27-48.
Kim, M., Flanagan, D.C., Frankenberger, J.R., Meyer, C. 2009. Impact of Precipitation Changes on Runoff and Soil Erosion in Korea using CLIGEN and WEPP. Journal of Soil and Water Conservation. 64(2):154-162.
Truman, C.C., Shaw, J.N., Flanagan, D.C., Reeves, D.W., Ascough II, J.C. 2009. Conservation Tillage to Effectively Reduce Interrill Erodibility of Highly-Weathered Ultisols. Journal of Soil and Water Conservation. 64(4):265-275. doi:10.2489/jswc.64.4.265.
Williams, J.D., Dun, S., Robertson, D.S., Wu, J.Q., Brooks, E., Flanagan, D.C., Mccool, D.K. 2010. WEPP Simulations of Dryland Cropping Systems in Small Drainages of Northeastern Oregon. Journal of Soil and Water Conservation Society. 65(1):22-33.
Jiang, T., Teng, L., Wei, S., Deng, L., Chen, Y., Luo, Z., Flanagan, D.C. 2010. Application of Polyacrylamide to Reduce Phosphorus Losses from 9 Chinese Purple Soil: A Laboratory and Field Investigation. Journal of Environmental Management. 91(7):1437-1445.