2013 Annual Report
1a.Objectives (from AD-416):
In recent years there has been increased interest in a more thorough understanding and accounting of the benefits of conservation practices to fish and wildlife. By integrating the research and assessment efforts across cropland and rangeland CEAP, the ultimate goal of this research is to develop an operational framework for assessing, reporting, and forecasting benefits to the full suite of ecosystem services affected by USDA conservation programs. The objective of this study is to construct, calibrate, validate and run land use and climate scenarios for SWAT simulations across the Western Lake Erie Basin. The SWAT outputs will be used as in-stream habitat predictor variables and will serve as inputs to the models developed to model biological indicators across the Western Lake Erie Basin.
1b.Approach (from AD-416):
The general approach is to link SWAT model output on stream flow and water quality to models that predict fish populations and habitat suitability. Data on soils, land cover and management, climate, flow and water quality will be assembled to develop input data and calibration data for the SWAT model of the Western Lake Erie Basin. We will ensure that geospatial identifiers of all stream networks are cross-walked to the common 1:100,000 scale National Hydrography Dataset network. Biological indicators will be developed from SWAT model output and the impact of climate and conservation practices on fish health will be determined.
Western Lake Eerie has recently experienced degraded water quality and severe eutrophication. Fish habitat and health within streams in the Western Lake Eerie Basin (58,800 km2) have also declined. To parameterize the SWAT model for the basin, all input data were assembled, including soils, climate, topographic, and land use and management. Available stream gage data, including flow, sediment, mineral and organic forms of nitrogen and phosphorus, were assembled for use in calibration and validation. SWAT simulations were parameterized and calibrated at the 12-digit scale (approximately 100 km2) and with subbasins defined by the National Hydrography Dataset commonly referred to as NHD+ (approximately 3 km2). A new and efficient calibration technique was developed by calibrating at the 12-digit scale, where stream gage data are available, and then scaling parameters down to the NHD+ scale.
Validated model simulations are being delivered to The Nature Conservancy and researchers in the basin to link SWAT output with fish health indicators. The linked model will provide a tool for the assessment of fish health for each mile of stream within the basin and also provide the capability of determining the impact of climate and land use scenarios on fish health and habitat.