Flash flood and sediment modeling with TREX

TREX is a physically-based, distributed model that simulates flash floods, sediment transport, and chemical transport and fate processes at the watershed scale. Basic processes in TREX include precipitation, interception, infiltration, surface runoff, and channel flow, erosion and deposition of upland soil and channel bed sediment, and chemical transport. TREX is readily coupled with standard GIS tools to facilitate data exploration, model set-up, and provides a visual analysis of numerical results. Model performance is demonstrated through several field applications. The detailed analysis of three field sites includes: (1) flash floods on the Arkansas River basin, CO; (2) sediment transport at Goodwin Creek, MS; and (3) chemical transport at California Gulch, CO. These field studies demonstrate the importance of the links between time-variable precipitation, surface runoff, and floodplain interactions and stream flow. In addition to the magnitude and timing of floods, these interactions also control the subsequent redistribution of sediments and associated contaminants and chemicals on the land surface when flood waters inundate flood plain areas.