PRELIMINARY HYDRO-METEOROLOGIC ASSESSMENT OF AN EXTREME PRECIPITATION EVENT ON SANTEE EXPERIMENTAL FOREST WATERSHEDS, SC

The abnormal precipitation event on October 3-4, 2015 reported to be likely contributed by a persistent deep easterly flow, the continuous supply of moisture, the terrain, and the circulation associated with Hurricane Joaquin in the eastern Atlantic Coast (http://cms.met.psu.edu/sref/severe/2015/04Oct2015.pdf) resulted in extreme and prolonged flooding in many parts of South Carolina (SC). We present the spatial and temporal analysis of precipitation amounts and their intensities observed at five gauges on the USDA Forest Service Santee Experimental Forest (SEF) watersheds during and 5-day prior to this extreme event and compare them against published design rainfall event data for the region. We also examine their potential impacts on flooding using recorded/estimated stream flow for the 1^st, 2^nd, and 3^rd order watersheds on this lower coastal plain forest. The high flow rates experienced during this event will also be compared against another large event that occurred on October 23-24, 2008 at this site. The recorded water levels in all ground water wells at the SEF are also being analyzed to determine the extent of surface ponding potentially causing the flooding at the site. The effects of this extreme precipitation event differ from that of the September 1989 Hurricane Hugo where extreme wind force impacted most of the vegetation at the site, potentially reducing its evapotranspiration. These analyses will provide insights into the magnitude, frequency, and duration of the floods and moisture regime caused by these extreme events for potential adaptive management of stormwater and forest vegetation as concerns of global warming continue.