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United States Department of Agriculture

Agricultural Research Service

Research Project: Conservation Effects Assessment Project Croplands Watersheds Studies - Gulf Coast & Western Watersheds (2012)

Location: Watershed Physical Processes Research

2013 Annual Report

1a. Objectives (from AD-416):
Problems to be addressed through this agreement include the following four areas: 1. Improving our understanding of the aggregate effects of conservation practices at the watershed scale; 2. Improving our ability to select and place conservation practices on the landscape for maximum effectiveness; 3. Improving conservation practices to better protect water resources; and 4. Maintaining the effectiveness of conservation practices under changing climate and land use. Statement of Work/Deliverables for Watershed Physical Processes, Oxford, MS: 1. Continue to collect rainfall data at a network of 28 tipping bucket rain gauges in and around the watershed. 2. Continue to collect stream discharge at 10 gauging stations nested within Goodwin Creek watershed channel system. 3. Continue to collect water quality samples at 5 gauging stations: distributed storm samples for sediment, flow-weighted composite samples for water quality, and first-flush samples for water quality. 4. Continue to collect monthly grab samples for base flow water quality analyses. 5. Continue to maintain two NRCS SCAN sites (one pasture, one forest) and a NOAA Surface Radiation Budget (SURFRAD) station. 6. Separate sediment samples into sands and fines and determine sediment concentration of each. 7. Analyze water quality samples for total P, TKN, DOC, filterable P, NO2, NO3, NH3, turbidity, total solids, dissolved solids. 8. Continue to conduct annual land use surveys. 9. Develop a Specific Cooperative Agreement with the Panola County Soil and Water Conservation District and through them pay farmers for land management operations and yield data. 10. Select six new edge-of-field gauging sites: two cropland, two pasture, and two forest. 11. Install gauging and sampling equipment and begin sampling six edge-of-field sampling sites. 12. Explore techniques to identify and characterize ephemeral gullies, buffers, stream cross sections, channel bed properties from remote sensing imagery and data. 13. Initiate cooperative research for analysis of remote sensing data to characterize cropping systems, tillage intensity, and crop yield. 14. Input Goodwin Creek climate, runoff, sediment yield, water quality, and land use data into STEWARDS.

1b. Approach (from AD-416):
Improving our understanding of the aggregate effects of conservation practices at the watershed scale: 1. Field studies to develop remote sensing tools to better evaluate cover crop performance (CB/ACP). 2. Develop models/decision support tools to assess the effectiveness of cover crops (CB/ACP) and other BMP’s (All) at the watershed scale. 3. Enhance the landscape version of SWAT to better represent field-to-basin scale processes (All). Improving our ability to select and place conservation practices on the landscape for maximum effectiveness: 1. Develop mapping techniques for placing specific practices within watersheds based on terrain and soils data. 2. Develop methods of terrain analysis for improved mapping of soil wetness in glacial terrain. 3. Validate the CEAP National Assessment conducted with SWAT at multiple scales. 4. Assess and compare the trade-offs of no-till adoption, and support the development of nutrient management recommendations for water quality protection, at the watershed scale. Improving conservation practices to better protect water resources: 1. Quantify nutrient management effects on water quality at field and watershed scales. 2. Watershed scale studies to systematically validate phosphorus site assessment tools in support of NRCS 590 (nutrient management) standard. 3. Watershed scale assessment of combined conservation practices. Maintaining the effectiveness of conservation practices under changing climate and land use: 1. Use reservoir sedimentation, land use change, and climate information to anticipate future reservoir sedimentation and needs for additional conservation under changing climate. 2. Enhance SWAT model routines for urban landscape BMPs. 3. Apply erosion (WEPP, etc.) and water quality (WEPP-WQ, etc.) models to catchments ranging from field- to farm-size and watershed scale, to assess the impacts of current and alternative land management systems and conservation practices under current and future climates.

3. Progress Report:
The principal focus of the Conservation Effects Assessment Project (CEAP) Watershed Studies is to evaluate the effects and benefits of conservation practices at the watershed scale, in support of policy decisions and program implementation. Work under this cooperative agreement includes routine site maintenance and data collection activities. Data at nine supercritical flumes within Goodwin Creek was collected. Parameters measured include stage, discharge, precipitation, and sediment concentration. To improve resolution of low flow conditions, additional pressure transducers have been fitted into the flumes to supplement acoustic stage measurements. A turbidity gauge has been successfully deployed at station #2 and its readings will be calibrated against sequential fine sediment samples collected there. Monitoring a network of 27 rain gauges was continued. Using funds from this project a part time, temporary hydrologic technician was hired to provide quality assurance and quality control procedures to contemporary and historical rainfall data. All gauge data within 30 days are being examined and report of anomalies will be submitted to the field team. The historical data is being gone through backwards systematically in order to improve the completeness and accuracy of the record. The Natural Resources Conservation Service (NRCS) Soil Climate Analysis (SCAN) and National Oceanic and Atmospheric Administration (NOAA) Surface Radiation (SURFRAD) weather stations located at site 50 continue to be maintained and supported. An agreement with a postdoctoral researcher at the University of Arizona to install and maintain a new soil moisture sensor at site 50. The Cosmic-ray Soil Moisture Observing System (COSMOS) sensor is designed to measure fast neutrons in the atmosphere. The abundance of fast neutrons is proportional to soil moisture. This method provides average soil moisture over an approximately 34 hectare area. A Specific Cooperative Agreement (SCA) has been developed with the North Central Mississippi Resource Conservation and Development Council (NCMRCDC) to improve understanding of management practices at the field scale. A questionnaire was jointly developed and administred to landowners to quantify the inputs of fertilizer and pesticides and the output of crop and animal yields. The NCMRCDC collected the records, removed personally identifiable information, and compensated landowners for their information. Questions were designed to provide land use information suitable for inputs to computer based runoff and erosion models including crop rotation, tillage, amendments, grazing, and forestry practices details. During 2013, three new edge-of-field sampling sites went on-line. One site drains a planted pine plantation, one site drains cropland, and one site drains pasture. Observations of macro-pore and pipe flow in the pasture site prompted researchers to add three additional monitoring sites within the 7 acre pasture site and to conduct tracer studies to determine the connectedness and transmission speeds of active pipes.

4. Accomplishments

Last Modified: 10/19/2017
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