High-resolution Radar Rainfall Records for Assessment of Hydroclimatology of the Christina River Basin

A high-resolution 15-minute, 1 km² radar rainfall data set for the warm season during the period of 2001-2010 was developed for the 1440 km² Christina River Basin. Daily rainfall observations from rain gauges were used to bias correct radar fields derived from volume scan reflectivity observations from the NEXRAD WSR-88D radar at Fort Dix, NJ. The bias-corrected radar rainfall data were used to assess the spatial and temporal structure of rainfall over the Christina River Basin and its four sub-watersheds: White Clay Creek (277 km²), Red Clay Creek (140 km²), Brandywine Creek (842 km²), and the tidal Christina River (202 km²). High-quality rain gauge data from within the intensively studied 7.5 km² 3rd order east fork of the east branch of White Clay Creek were supplemented with the additional spatial rainfall distribution information provided by the radar rainfall product to create a more complete picture of prescription patterns over this long-term highly-instrumented research watershed. The high-resolution long-term bias-corrected radar rainfall data set will also be used in hydrologic modeling for the Christina River Basin Critical Zone Observatory.