Submitted to: International Symposium on River Sedimentation
Publication Type: Proceedings
Publication Acceptance Date: 6/18/2010
Publication Date: 9/6/2010
Citation: Romkens, M.J. 2010. Current Erosion and Sediment Research Concerns in Agricultural Watersheds in the USA. International Symposium on River Sedimentation. 43-51. Interpretive Summary: Erosion and sedimentation are natural processes that occur most everywhere on the globe. Where man has settled and used the land for food production, the processes of erosion and sedimentation have accelerated, sometimes to catastrophic levels. History is replete with examples of land areas that were devastated due to the mismanagement of land. The catastrophic conditions of land erosion that developed in the USA by the European settlers between 1830 and 1930 were the inspiration for legislation to address this problem through research of programs that initially consisted of soil loss measurements on natural runoff plots and small agricultural watersheds. This work adventurously culminated in analytical and modeling approaches to provide more generality to soil erosion and conservation research finds. Also, what was originally intended to address soil erosion on upland area (on-site) problems in due time shifted in emphasis to the stream system (off-site) water quality issues. In recent years, the scale of concern has been further enlarged to include dam safety and stability issues. This paper presents a birds-eye view of how the agricultural research program in soil erosion and conservation has changed of the course of history.
Technical Abstract: Soil erosion research programs in the USA began in earnest following events of the 1933 Dust Bowl. During the early years from the 1930s-1960s, the focus was on determining the scale and severity of this problem by making measurements on plots, field-size areas, and small agricultural watersheds. The purpose was to assess the effect on soil productivity and to arrive at agricultural soil conservation measures and practices. In the 1970s - 1990s the research focus shifted gradually to water quality concerns of open water bodies such as lakes and streams. That interest was soon followed by concerns for the ecology. While these concerns are still in the fore front of research attention and interest, in recent years other issues are taking center stage in the hierarchy of research priorities. Those issues relate to environmental, economic, and security matters. This presentation addresses these issues as they have developed within the USDA of the USA. They are: (1) TMDLs or Total Maximum Daily Loads which are the permissible loading levels of pollutants of streams and open water bodies that impair specific water usage such as public consumption, industrial use, or recreation; (2) CEAP or the Conservation Effect Assessment Project which is concerned with the efficiency and effectiveness of conservation practices that have cost the U.S. Government billions of dollars over the years and which have not had a proper cost/benefit analysis. (3) Dam Safety and Stability. This concern has risen as a result of the increased frequency of dam failure of which thousands were built in the 1940s-1970s for storing water for domestic or industrial use or as sedimentation basins. These structures were built with a lifetime of fifty years which has now been reached. This presentation will briefly discuss these issues and the problems involved.