Sunday, 10 August 2003
Potential application of mobile X-band radar for catchment hydrology
Major storm systems passing over the 21.4 km2 Goodwin Creek research watershed in northern Mississippi are analyzed to evaluate the potential use of high resolution observations made by local-scale Doppler radar to estimate rainfall accumulation relevant for catchment hydrology. Issues of space-time resolution and variability of rainfall are discussed by means of a direct comparison of the X-Band radar observations to those made by a regional-scale NEXRAD WSR-88D S-Band radar, and detailed surface rainfall measurements. Instrumentation of the Goodwin Creek catchment includes approximately 45 rain gauges of varying design (above ground and buried), a raindrop disdrometer, and three anemometers mounted at different heights to observe the wind profile. The presentation will highlight the difficulties involved in obtaining accurate rainfall measurements from point and remote-sensing sources. A particular challenge poses the problem of potentially very severe attenuation for X-band radar observations in extreme rainfall.