Investigations of Runoff and Sediment Yield from Pinyon-Juniper Watersheds, Northern New Mexico

PItlick, John; Wilcox, Bradford; Reneau, Steven; Allen, Craig

This proposal seeks 3 years of funding to further develop a study of erosion and sediment transport in the pinyon-juniper woodlands of the Pajarito Plateau, northern New Mexico. The study will be conducted in Los Alamos National Laboratory and Bandelier National Monument in selected areas that are experiencing various levels of erosion from from slight to severe. Results from a pilot project initiated 2 years ago suggest that in some areas the present-day rates of erosion are extreme and the sustainability of the pinyon-juniper ecosystem is at risk. The proposed study expands upon this work by addressing the following questions in greater detail: 1) when did the present cycle of erosion begin and why? 2) what are the present-day rates of erosion? 3) what do the present-day erosion rates signify about the sustainability of this ecosystem? 4) which among the factors of slope, precipitation, aspect and soils influence erosion the most? 5) how is sediment eroded from the mesa tops distributed and stored in the valley bottoms? In the expanded study, many more plots will be established to measure surface erosion. These plots will be selected systematically to represent a wide range in environmental conditions. In addition, the pattern and volume of sediment stored in stream valleys will be measured. The final goal is to use existing high resolution digital elevation data and vegetation data to develop a GIS-based model of soil erosion. Specifically the GIS will be used to map the coincidence of factors that make an area susceptible to erosion. The proposed study is a collaborative effort between scientists at the University of Colorado, Los Alamos National Laboratory and Bandelier National Monument. As such, several different areas of expertise are represented and many resources are available. The results of the project will have important implications for managing resources within Los Alamos National Laboratory and Bandelier National Monument. Specifically, there is concern that accelerated soil erosion has already had an impact on many archaeological sites and may represent a threat to some hazardous waste sites. Beyond the study area, there are several federal agencies (e.g. U.S. Forest Service, Bureau of land Management and the National Park Service) that can utilize results from this project in developing their own strategies for managing pin yon-juniper woodlands.