2008 Joint Annual Meeting (5-9 Oct. 2008): Assessment of Watershed and Site-specific Characteristics in Relation to Streambank Erosion.

758-1 Assessment of Watershed and Site-specific Characteristics in Relation to Streambank Erosion.



Wednesday, 8 October 2008
George R. Brown Convention Center, Exhibit Hall E
Mustafa Tufekcioglu, 215 Science II, Iowa State University, Iowa State University, Natural Resource Ecology and Management, Ames, IA 50011, Thomas M. Isenhart, Dept. of Natl Res. Ecology & Mngmnt, Iowa State University, 339 Science II, Ames, IA 50011, James R. Russell, Animal Science, Iowa State University, 337 Kildee Hall, Ames, IA 50011, John L. Kovar, USDA-ARS National Soil Tilth Laboratory, USDA-ARS National Soil Tilth Laboratory, 2110 University Blvd., Ames, IA 50011-3120 and Richard C. Schultz, Iowa State University, Dept. of Natl Res. Ecology & Mngmnt, 339 Science Ii Iowa State Univ. ity, Ames, IA 50011-3221
An emerging challenge in watershed-scale research is to not only quantify the amount of sediment contributed to receiving waters  from various erosion processes but also to identify the extent of major  source areas, and to develop management strategies to reduce sediment and nutrient inputs. In this on-going study, watershed and site-specific characteristics including basin area, drainage density, stream bed slope, length and sinuosity, land cover by stream order, eroded stream length and area, bank erosion rates and stocking rates (cow-days ha-1 yr-1) were calculated for the assessment of current watershed conditions and stream health. Total surveyed watershed area and stream length in the study were 163 km2 and 317 km, respectively. Our long-term objective for this project is to assess the current riparian land-uses and stream characteristics of the study sites and throughout the watersheds, and identify any interactions between stream bank erosion parameters and watershed and/or site-specific characteristics. Current watershed assessment showed that within the 50 m corridor on both sides of the stream, 46 to 61 % of riparian area was devoted to agricultural use and only 6 to 11 % was in CRP and with the rest mainly in unmanaged use. Intensive agricultural use in riparian areas can be directly related to excessive amounts of sediment and nutrient load to streams and lakes and their impairment of providing insufficient ecological services.