Jerry C. Ritchie, USDA ARS Hydrology and Remote Sensing Laboratory, BARC-West Building-007, 10300 Baltimore Avenue, Beltsville, MD 20705
Streambank and gully erosion are significant factors contributing to soil loss from the landscape and for understanding sediment budgets. They need to be measured and evaluated quantitatively at large scales to understand their effects in natural and agricultural landscapes. It is difficult and time consuming to measure these landscape properties at scales that are large enough to be useful for understanding soil loss and sediments budgets using ground measurements. Many studies have shown that airborne lidar altimeter data can be used measure topography, gully and stream cross sections. The agreement between lidar and field measurements is good for these topographic features. Airborne lidar measurements of channels and gullies have been used to estimate soil loss and explain water quality and flow patterns. Lidar offers the potential to measure land surface features and properties over large areas quickly and easily. Such measurements will improve our understanding of the effect of channel and gully erosion on hydrologic systems in natural and agricultural landscapes. Lidar altimetry is an additional tool in the arsenal of remote sensing tools that used to understand channel and catchment properties and to develop plans to manage water resources.