2008 Annual Report
This project is part of the USDA-ARS NP # 211: Water Availability and Watershed Management. The research carried out under this project plan addresses Problem Area 4 - Integrated Soil Erosion and Sedimentation Technologies, Product 2 – Sediment Yield Data Bases., Product 5 – Best Management Practices.
2. Development of a rangeland hydrology and erosion model. Currently, there are no accepted or scientifically defensible tools to estimate the effects of climate, fire, and management on hydrology and erosion on rangelands. ARS scientists in the Southwest Watershed Research Unit in Tucson, AZ developed a new set of rangeland based sediment source terms for the Rangeland Hydrology and Erosion Model (RHEM) and performed parameter estimation analysis with rainfall simulator studies. These results have positive implications for the rangeland Conservation Effects Assessment Project, which is intended to make broad scale assessments of the benefits of federally-funded conservation practices on western US rangelands. RHEM will be used as the basic assessment tool for that project. NP 211 Problem Area 4 - Integrated Soil Erosion and Sedimentation Technologies, Product 5 – Best Management Practices. 3. Sediment Identification Techniques for Determining Sediment Source. Sediment is a major pollutant in many watershed streams and identification of sediment sources is critical to provide cost effective management to these watersheds and reduce sediment pollution. Using sediment identification techniques, ARS scientists in the Southwest Watershed Research Unit in Tucson, AZ determined that three subwatersheds on Walnut Gulch Experimental Watershed were contributing 86% of the sediment load from the watershed and that 65% of the stable carbon isotope leaving the watershed was from shrub plants that dominate the vegetation on the three subwatersheds. Land managers and landowners using the sediment identification techniques can now determine areas where they should focus their limited resources to produce the greatest reduction in sediment loads. NP 211 - Problem Area 4 - Integrated Soil Erosion and Sedimentation Technologies, Product 2 – Sediment Yield Data Bases.
4. Alternative future land cover scenarios used with hydrologic model to identify areas with potential erosion and water quality problems. There is critical need to assess, report, and forecast the life support functions of ecosystems to ensure we can maintain the sustainable nature of our environmental services and secure these resources into the future. Landscape metrics, in con¬junction with hydrological process models, were used, by ARS scientists in the Southwest Watershed Research Unit in Tucson, AZ, to examine the contribution of land use/land cover change to water and sediment yield and identify subwatersheds within the Willamette River Basin (Oregon, USA) that would be most affected in the year 2050 relative to three possible future growth and development scenarios which include inherent differences related to conservation, planning, and open development as compared to circa 1990 land cover. This study presents an integrated approach to identify areas with potential water quality problems as a result of land cover change projected by stakeholders within the basin;specifically, the impact of both urban and agricultural development in a large river basin. NP 211 Problem Area 4 – Integrated Soil Erosion and Sedimentation Technology, Product 2 – Sediment Yield Data Bases.
5. Sediment transport characteristics in semiarid channels.
The full particle size distribution of sediment transported in low-order ephemeral channel is unknown. Sediment was collected by ARS scientists in the Southwest Watershed Research Unit in Tucson, AZ during runoff events for three seasons of flow on Walnut Gulch. The distribution of particles across the complete set of classes transported was quantified and related to channel and hydrologic characteristics. This data set will be critical for improving channel sediment transport models, such as those being proposed for the rangeland Conservation Effects Assessment Project program. This accomplishment is in association with: Hypothesis 1, NP211 Action Plan Component - Problem Area 4 - Integrated Soil Erosion and Sedimentation Technologies, NP Action Plan Problem Statement - Product 2 – Sediment Yield Data Bases6. The impact of rock check dams on sediment, soil moisture, and vegetation
Rock check dams are a common erosion control practice on rangelands. Their impact is anecdotally described, but there is little quantitative data describing their impact. Sediment retention, soil moisture, and vegetation were measure during a field experiment by ARS scientists in the Southwest Watershed Research Unit in Tucson, AZ to compare loose rock check dams with rock and wire structures on a rangeland pasture. This work provides quantitative information that will be useful for designing and implementing additional rangeland treatment using low tech erosion control structures.
This accomplishment is in association with: Hypothesis 1 NP 211 Action Plan Component - Problem Area 4 - Integrated Soil Erosion and Sedimentation Technologies. NP Action Plan Problem Statement - Product 2 – Sediment Yield Data Bases.
5.Significant Activities that Support Special Target Populations
SWRC scientists are actively participating in a mentoring program through collaboration with the University of Arizona/NASA Space Grant Program. The program matches outstanding undergraduate students from underrepresented groups with mentors from the SWRC to work together on projects developed by mentors. The ultimate goal of the program is to "grow our own" scientists from underrepresented groups. Over the last four years, twelve students (Hispanic, African-American, women) have come through the program. This year two women completed the program under this project.
Skirvin, S., Kidwell, M., Biedenbender, S.H., Henley, F.P., King, D.M., Holifield Collins, C.D., Moran, M.S., Weltz, M.A. 2008. Vegetation Data, Walnut Gulch Experimental Watershed, Arizona, United States. Water Resources Research, Vol. 44, W05S08, doi:10.1029/2006WR005724.
Al-Qurashi, A., Mcintyre, N., Wheater, H., Unkrich, C.L. 2008. Application of the Kineros2 rainfall-runoff model to an arid catchment in Oman. Journal of Hydrology. 355:91-105.
Rhoton, F.E., Emmerich, W.E., Dicarlo, D.A., Mcchesney, D.S., Nearing, M.A., Ritchie, J.C. 2008. Identification of Suspended Sediment Sources Using Soil Characteristics in a Semiarid Watershed. Soil Science Society of America Journal. 72(4): 1102-1112.
King, D.M., Skirvin, S., Holifield Collins, C.D., Moran, M.S., Biedenbender, S., Kidwell, M., Weltz, M.A., Diaz-Gutierrez, A. 2008. Assessing Vegetation Change Temporally and Spatially in Southeastern Arizona. Water Resources Research, Vol. 44, W05S15, doi:10.1029/2006WR005850.
Heilman, P., Nichols, M.H., Goodrich, D.C., Miller, S.N., Guertin, D.P. 2008. Geographic information systems database, Walnut Gulch Experimental Watershed, Arizona, United States. Water Resources Research, Vol. 44, W05S11, doi:10.1029/2006WR005777.
Renard, K.G., Nichols, M.H., Woolhiser, D.A., Osborn, H.B. 2008. A brief background on the U.S. Department of Agriculture Agricultural Research Service Walnut Gulch Experimental Watershed. Water Resources Research. Vol. 44, W05S02, doi:10.1029/2006WR005691.
Peters-Lidard, C.D., Mocko, D.M., Garcia, M., Santanello Jr., J., Tischler, M., Moran, M.S., Wu, Y. 2008. Role of precipitation uncertainty in the estimation of hydrologic soil properties using remotely sensed soil moisture in a semi-arid environment. Water Resources Research, Vol. 44, W05S18, doi:10.1029/2007WR005884.
Moran, M.S., Holifield Collins, C.D., Goodrich, D.C., Qi, J., Shannon, D.T., Olsson, A. 2008. Long-term remote sensing database, Walnut Gulch Experimental Watershed, Arizona, United States. Water Resources Research. Vol. 44, W05S10, doi:10.1029/2006WR005689.
Nichols, M.H., Stone, J.J., Nearing, M.A. 2008. Sediment database, Walnut Gulch Experimental Watershed, Arizona, United States. Water Resources Research. Vol. 44, W05S06, doi:10.1029/2006WR005682.
Nichols, M.H., Anson, E. 2008. Southwest Watershed Research Center Data Access Project. Water Resources Research. Vol. 44, W05S03, doi:10.1029/2006WR005665.
Rahman, M.M., Moran, M.S., Thoma, D.P., Bryant, R., Holifield Collins, C.D., Jackson, T.J., Orr, B.J., Tischler, M. 2008. Mapping surface roughness and soil moisture using multi-angle radar imagery without ancillary data. Remote Sensing of Environment. 112:391-402.
Kepner, W.G., Hernandez, M., Semmens, D., Goodrich, D.C. 2008. The Use of Scenario Analysis to Assess Future Landscape Change on Watershed Condition in the Pacific Northwest (USA). In: Use of Landscape Sciences for Environmental Security, Springer Publishers, The Netherlands. pp. 237-261.
Moran, M.S., Emmerich, W.E., Goodrich, D.C., Heilman, P., Holifield Collins, C.D., Keefer, T.O., Nearing, M.A., Nichols, M.H., Renard, K.G., Scott, R.L., Smith, J.R., Stone, J.J., Unkrich, C.L., Wong, J.K. 2008. Preface to special section on Fifty Years of Research and Data Collection: U.S. Department of Agriculture Walnut Gulch Experimental Watershed. Water Resources Research, Vol. 44, W05S01, doi:10.1029/2007WR006083.
Browning-Aiken, A., Morehouse, B., Davis, A., Wilder, M., Varady, R., Goodrich, D.C., Carter, R., Moreno, D. 2007. A climate, water management, and policy in the San Pedro Basin: Results of a survey of mexican stakeholders near the U.S.–Mexico border. Climate Change. 85(3-4): 323-341.
Nearing, M.A., Nichols, M.H., Stone, J.J., Renard, K.G., Simanton, J.R. 2008. Sediment yields from unit-source semi-arid watersheds at Walnut Gulch. Water Resources Research. Vol. 43, W06426, doi:10.1029/2006WR005692.
Watts, C.J., Scott, R.L., Garatuza-Payan, J., Rodriguez, J.C., Prueger, J.H., Kustas, W.P., Douglas, M. 2007. Changes in vegetation condition and surface fluxes during name 2004. Journal of Climate. 20: 1810-1820.
Magirl, C.S., Webb, R.H., Schaffner, M., Lyon, S.W., Griffiths, P.G., Shoemaker, C., Unkrich, C.L., Yatheendrades, S., Troch, P.A., Pytlak, E., Goodrich, D.C., Desilets, S.L., Youberg, A., Pearthree, P.A. 2007. Impact of Recent Extreme Arizona Storms. EOS 88(17): 191-193.
Wei, H., Nearing, M.A., Stone, J.J., Breshears, D.P. 2008. A dual-monte-carlo approach to estimate model uncertainty and its application to the rangeland hydrology and erosion model. Trans. Am. Soc. Agric. Bio. Eng. 51(2): 515-520.