Location: Southwest Watershed Research
2013 Annual Report
Objective 2. Develop decision tools including a rangeland specific hydrology and erosion model for improved planning and evaluation of rangeland management practices.
Rainfall simulator experiments were conducted on four sites of the Loamy Upland ecological site at the Walnut Gulch Experimental Watershed and at the Empire Ranch. Data from the overland flow part of the experiment were used with overland flow data from ARS Boise, Idaho, to determine the structure of the concentrated flow erodibility parameter estimation equation for the Dynamic Rangeland Hydrology and Erosion Model (DRHEM). Progress was made to scan and upload historic photos to the Rangescpae.com website. Photo points have been relocated in the San Simon Watershed. Tools for creating tiepoints and co-registering temporally sequential photos have been developed and implemented through the Rangescape.com website. In addition, tools for annotating, storing, and managing user contributed content have been implemented. Time-lapse hardware has been built and deployed at 3 field sites in Arizona.
A geodatabase of sediment control and retention structures (including stock ponds) has been developed in cooperation with the University of Arizona Department of Arid Lands and the Graham County Cooperative Extension Office. In addition, the Arizona Department of Water Resources stock tank permit database has been evaluated with respect to aerial imagery to verify stock tank locations in both the San Simon and Las Cienegas Watersheds. The unit's stock tank runoff data through 2012 has been integrated and made available through the unit's database website.
The steady-state solution of the RHEM equations were solved within the dynamic framework of KINEROS2, with additional capability to dynamically update soil erodibility parameters for both concentrated and sheet flow within storm events. The resulting model, DRHEM, was integrated into a web site application. Results of research in collaboration with ARS in Boise, Idaho, were used to develop parameter estimation equations for concentrated flow on disturbed rangeland sites. DRHEM was fully integrated into the KINEROS2 model for use in rangeland Conservation Effects Assessment Project (CEAP) evaluations done in collaboration with the Natural Resources Conservation Service (NRCS).
A spatial database of grazed and ungrazed management units across Arizona was refined by developing a method to resolve inconsistent boundaries and attribute tables. The database has gaps where public data are not available. Further improvement of this layer will require coordination between the different land management agencies, for example, agreement on common boundaries between adjoining allotments held by the Forest Service and Bureau of Land Management. A spatial database of areas with NRCS conservation practices applied between 2003 and 2006 was assessed.
Nichols, M.H., Nearing, M.A., Polyakov, V.O., Stone, J.J. 2012. A sediment budget for a small semiarid watershed in southeastern Arizona, USA. Geomorphology. 180-181: 137-145.
Cerdà, A., Brazier, R., Nearing, M.A., De Vente, J. 2013. Scales and erosion. Catena. 102:1-2.
Al-Hamdan, O.Z., Pierson Jr, F.B., Nearing, M.A., Williams, C.J., Stone, J.J., Kormos, P.R., Boll, J., Weltz, M.A. 2012. Concentrated flow erodibility for physically-based erosion models: temporal variability in disturbed and undisturbed rangelands. Water Resources Research. DOI: 10.1029/2011WR011464.
Nichols, M.H., Mcreynolds, K., Reed, C. 2012. Short-term soil moisture response to low-tech erosion control structures in a semi arid rangeland. Catena. 98:104-109.
Reike-Zapp, D., Nichols, M.H. 2011. Headcut retreat in a semiarid watershed in the southwestern United States since 1935. Catena. 87(1):1-10.
Al-Hamdan, O.Z., Pierson Jr, F.B., Nearing, M.A., Williams, C.J., Stone, J.J., Kormos, P.R., Boll, J., Weltz, M.A. 2013. Risk assessment of erosion from concentrated flow on rangelands using overland flow distribution and shear stress partitioning. Transactions of the ASABE. 56(2):539-548.
Delgado, J.A., Nearing, M.A., Rice, C. 2013. Conservation practices for climate change. Advances in Agronomy. 121:47-115.
Ascough II, J.C., Flanagan, D.C., Nearing, M.A., Engel, B.A. 2013. Sensitivity and first-order/Monte Carlo uncertainty analysis of the WEPP hillslope erosion model. Transactions of the ASABE. 56(2)/437-452.
Guzmán, G., Quinton, J., Nearing, M.A., Mabit, L., Gómez, J. 2013. Sediment tracers in water erosion studies: Current approaches and challenges. Journal of Soils and Sediments. 13:816–833.
Polyakov, V.O., Nearing, M.A., Hawdin, A., Wilkinson, S., Nichols, M.H. 2013. A comparison of two stream gauging systems for measuring runoff and sediment yield on semi-arid wtershed . Earth Surface Processes and Landforms. 38: 383–390.
Sanches Oliveira, P., Wendland, E., Nearing, M.A. 2013. Rainfall erosivity in Brazil: A Review. Catena. 100:139–147.