2013 Annual Report
1a.Objectives (from AD-416):
Determine the effect of current agricultural practices on modeled runoff, sediment loads, and chemical losses under current climate conditions. Compare modeled outputs to observed values for runoff, sediment loads, and chemical losses from plots and watersheds. Test the effects of different types and levels of conservation practice implementation on predicted runoff, sediment load, and chemical losses under existing and future climate scenarios.
1b.Approach (from AD-416):
This project involves computer simulation modeling studies in the St. Joseph River Watershed, located in northeastern Indiana, and part of the Conservation Effects Assessment Project (CEAP). Natural resource models, including the Soil and Water Assessment Tool (SWAT) and the Water Erosion Prediction Project (WEPP) models, will be applied to locations monitored by ARS-CEAP participating scientists. Geographic Information System (GIS) layers necessary for detailed model simulations will need to be developed, including the most up-to-date topographic, soils, land-use, and climate information. Models will be calibrated and validated to assure satisfactory performance with existing observed climate, runoff, nutrient and soil loss data. Then, additional model simulations will be conducted to determine the effects of implementing different conservation practices, as well as increased levels of conservation practices under existing climate. Down-scaled regional climate projections from Global Environmental Models (GEMs) will be used to produce new climate inputs to the erosion/water quality models to assess the effectiveness of the conservation practices under the projected future climate changes. Analysis of the results will determine if current conservation practice recommendations will be sufficient to maintain the soil and water natural resources. Results will be published in reports and peer-reviewed scientific journals.
Climatic, topographic, and soil input GIS layers for SWAT model simulations have been completed for the Upper Cedar Creek watershed in northeastern Indiana. Current work is on creating detailed land management information for each Hydrologic Response Unit (HRU), utilizing the farmer/cooperator data provided by the NSERL cooperators in the watershed and subwatersheds. This should be completed by the end of summer 2013, allowing for SWAT model calibration/validation with the observed streamflow and chemical concentrations.