9528886 Smith The proposed research will focus on describing aspects of precipitation and its erosivity. The work will show how to make use of radar to provide rainfall rate and rainfall kinetic energy concurrently, while covering a large area with high spatial and temporal resolution. Rainfall intensity and kinetic energy characterize the aspects of precipitation relevant to soil erosion and have to be monitored accurately to obtain improved soil loss estimates. Relatively sparse networks of raingauges have been used to estimate long-term soil loss. One of the largest potential benefits of using radar is augmenting such sparse gauge networks to provide comprehensive coverage for areas that are subject to erosion. Improved estimation and greater flexibility are likely to be gained and research opportunities created by making use of the newly available radar information provided by the Next Generation Weather Radar (NEXRAD) network of WSR-88D (Weather Surveillance Radar - 1988 Doppler). We will explore in depth the usefulness and limitations of radar for soil erosion studies and investigate and spatial and temporal distributions of rain rate and rainfall kinetic energy. Detailed comparisons will be made to test the performance of the radar-based approach to estimate precipitation erosivity versus present practice which depends exclusively on raingauge records. The study will be made on the basis of data collected in the Goodwin Creek research watershed in northern Mississippi. This watershed is under radar coverage from two NEXRAD WSR-88Ds, Memphis (Tennessee) and Little Rock (Arkansas). We will use data from the Memphis radar because of its proximity to the catchment. In addition to the existing raingauges in the already highly instrumented Goodwin Creek watershed, we will deploy a disdrometer for the automated measurement of raindrop size Distributions.
