Latest Science Results (not yet published)
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Assessing hillslope heterogeneity for rainfall-runoff modeling: KINEROS 2 case study
Event to Multi-decadal Persistence in Spatial Rainfall and Rainfall and Runoff as a Function of Spatial and Temporal Scales
Investigating uncertainty in distributed flash-flood forecasting for semi-arid regions
DotAGWA: A case study in web-based architecture for connecting surface water models to spatially enabled web applications
A Dual-Monte-Carlo Approach to Estimate Model Uncertainty: Application to the Rangeland Hydrology and Erosion Model
Quantifying Riparian Evapotranspiration
Separation and Measurement of Soil Carbon Dioxide Organic and Inorganic Fluxes
Tree growth response to zero-flow events: Can tree rings be used to reconstruct streamflow intermittency?
Fifty Years of research and data collection, USDA-ARS Walnut Gulch Experimental Watershed
Partitioning evapotranspiration in semiarid grassland and shrubland ecosystems using time series of soil surface temperature
Evaluating Hydrological Response To Forecasted Land-Use Change
Carbon exchange variability associated with meteorology, physiology, phenology, and water availability in semiarid riparian ecosystems
Post wildfire runoff and erosion from oak woodlands in southeastern Arizona, USA
Simposio Internacional Sobre Sistemas de Apoyo para la Toma de Decisiones en el Manejo de los Recursos Naturales
Remote Sensing of Rangeland Health in Southeastern Arizona
Localizing the Rangeland Health Method for Loamy Upland in Southeastern Arizona
Creating Decision Support Systems for Arid Environments
Highlight from Recently Published Research
Water is a critical element in the productivity of semi and arid ecosystems. Determining how efficient different ecosystems are at utilizing water to produce biomass is important to our understanding of how the ecosystems function and interact. The above graph is a plot of daily 2002 carbon dioxide vs evapotranspiration (ET) flux for our Kendall grass study site on WGEW. Negative carbon dioxide flux values are uptake of carbon into biomass for the ecosystem. The circle data points along the dashed line indicate the maximum carbon uptake for the minimum water use. The slope of the dashed line is a measure of the maximum water use efficiency for this ecosystem and we can use it to compare maximum efficiency with other ecosystems. The square data point are days of less water use efficiency. This figure shows us that for the days the ecosystem is taking up carbon, it is not functioning at maximum water use efficiency and there are a small number of days during the year for carbon uptake. Figure 2, W.E. Emmerich, Rangeland Ecology and Management, 60:464-470, 2007.
Papers Published Since July:
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Wagener, T., Gupta, H., Yatheendradas, S., Goodrich, D.C., Unkrich, C.L., Schaffner, M. 2007. Understanding sources of uncertainity in flash-flood forecasting for semi-arid regions. International Association of Hydrologic Sciences. 313:204-212. (1654 KB PDF)
Malone, R.W., Huth, N., Carberry, P.S., Ma, L., Kaspar, T.C., Karlen, D.L., Meade, T., Kanwar, R.S., Heilman, P. 2007. Evaluating and predicting agricultural management effects under tile drainage using modified APSIM. Geoderma. 140:310-322. (1025 KB PDF)
Malone, R.W., Ma, L., Karlen, D.L., Meade, T., Meek, D., Heilman, P., Kanwar, R.S., Hatfield, J.L. 2007. Empirical analysis and prediction of nitrate loading and crop yield for corn-soybean rotations. Geoderma. 140(3): 223-234. (779 KB PDF)
Malone, R.W., Ma, L., Heilman, P., Karlen, D.L., Kanwar, R.S., Harfield, J. 2007. Simulated N Management Effects on Corn Yield and Tile-Drainage Nitrate Loss. Geoderma. 140:272-283 (738 KB PDF)
Santanello, Jr, J.A., Peters-Lidard, C.D., Garcia, M.E., Mocko, D.M., Tischler, M.A., Moran, M.S., Thoma, D.P. 2007. Using remotely-sensed estimates of soil moisture to infer soil texture and hydraulic properties across a semi-arid watershed. Remote Sensing of Environment. 110:79-97. doi:10.1016/j.rse.2007.02.007 (1693 KB PDF)
Wei, H., Nearing, M. A., Stone, J.J. 2007. A new sensitivity analysis framework for model evaluation and improvement using a case study of the Rangeland Hydrology and Erosion Model. Trans. Am. Soc. Agric. Bio. Eng. 50(3): 945-953. (1235 KB PDF)
Bulygina, N.S., Nearing, M.A., Stone, J.J., Nichols, M.H. 2007. DWEPP: A dynamic soil erosion model based on WEPP source terms. Earth Surface Proceses and Landforms. 32:998-1012. (520 KB PDF)
Miller, S.N., Guertin, D.P., Goodrich, D.C. 2007. Hydrologic Modeling Uncertainty Resulting from Land Cover Misclassification. Journal of the American Water Resources Association. 43(4):1065-1075. (1015 KB PDF)
Emmerich, W.E. 2007. Ecosystem water use efficiency in a semiarid shrubland and grassland community. Rangeland Ecology and Management. 60:464-470. (205 KB PDF)
Yepez, E.A., Scott, R.L., Cable, W.L., Williams, D.G. 2007. Intraseasonal variation in water and carbon dioxide flux components in a semiarid riparian woodland. Ecosystems. 10:1100-1115. (472 KB PDF)
Scott, R.L., Williams, D.G., Huxman, T.E., Hultine, K.R., Goodrich, D.C. 2008. Quantifying Riparian Evapotranspiration. Southwest Hydrology. 7(1): 26-27 (716 KB PDF)
Jackson, R.J., Moran, M.S., O'Neill, P.E. 2008. Introduction to Soil Moisture Experiments 2004 (SMEX04) Special Issue. Remote Sensing of Environment 112:301-303. (102 KB PDF)
Rahman, M.M., Moran, M.S., Thoma, D.P., Bryant, R., Holifield Collins, C.D., Jackson, T., Orr, B.J., Tischler, M. 2008. Mapping surface roughness and soil moisture using multi-angle radar imagery without ancillary data. Rem. Sens. Env. 112:391-402. (1958 KB PDF)
Thoma, D., Moran, M.S., Bryant, R., Rahman, M., Holifield Collins, C., Keefer, T.O., Noriega, R., Osman, I., Skirvin, S., Tischler, M., Bosch, D., Starks, P.J., Peters-Lidard, C. 2008. Appropriate scale of soil moisture retrieval from high-resolution radar imagery for bare and minimally vegetated soils. Remote Sensing of Environment. 112:403-414. (1248 KB PDF)
Cosh, M.H, Jackson, T.J., Moran, M.S., Bindlish, R. 2008. Temporal persistence and stability of surface soil moisture in a semi-arid watershed. Rem. Sens. Env. 112:304-313 (722 KB PDF)
Our full publication list is available at
Future Science Events:
Click here for information about upcoming conferences, workshops and meetings, including the 3rd ICRW, 5th RISE and annual state-wide Space Grant Symposium.
WGEW and SRER data can be downloaded from the web site at http://www.tucson.ars.ag.gov/dap
Geographic locations of the three precipitation records can be found at http://www.ars.usda.gov/sp2UserFiles/Place/53424500/images/sw_az3.jpg
SWRC Scientists contributed to science teams that won three prestigious awards in 2007, including the Nobel Peace Prize. Click here for more information.
Click here for an introduction to our new staff members Mike Honea and Erik Hamerlynck and other news about staff activities.
Contact the SWRC Research Leader, Dr. Mark Nearing at 670-6380 x152 or firstname.lastname@example.org. Mailing address is USDA ARS SWRC, 2000 E. Allen Rd., Tucson, AZ 85719 and web address is http://www.tucson.ars.ag.gov/ . The SWRC Bulletin is on—line at http://ars.usda.gov/News/News.htm?modecode=53-42-45-00.
To develop knowledge and technology to conserve water and soil in semi-arid lands.