9732402 Ogden A small exploratory grant is proposed to employ advanced state of the art remote sensing and rainfall/runoff modeling approaches to examine the meteorology, runoff and channel hydraulics of the catastrophic flood which occurred on the Spring Creek drainage on July 28, 1997 in Fort Collins, Colorado. This flood resulted in an estimated 50 to 100 million dollars of damage to Colorado State University alone. Additional damages include the devastation of two mobile homes courts, flooding of numerous homes, multiple injuries and the unfortunate deaths of five people. The proposed study is a collaborative effort between researchers at the University of Connecticut, University of Missouri, and Princeton University. The researchers involved have extensive experience in radar-rainfall estimation, hydrologic scaling, and the development of state of the art rainfall/runoff models which incorporate remotely-senses data. The objectives of this proposed study are to (1) characterize the meteorological conditions which existed on the evening of July 28 leading to over 11 inches of rainfall in less than three hours on the watershed; (2) calibrate and verify radar-rainfall estimates from the NSF-funded CSU-CHILL S-band dual-polarization research radar, and the two WSR-88D NEXRAD radars located near Denver, Colorado and Cheyenne, Wyoming, using surface recorded rainfall accumulations; (3) collect and organize watershed characteristic and flood data using GIS; (4) apply the rainfall and watershed characteristic data to recreate the runoff event using a two-dimensional, physically-based hydrologic model; and (5) compare and contrast the performance of two-dimensional runoff simulation results with a recreation of the flood using the more traditional SWMM and HEC-2 approaches for flood warning and hydrologic design. The collaborative proposers are uniquely positioned to perform this research because they immediately sought and obtained data relevant to the flood. Additionally, the c ollaborative research team has conducted a significant amount of research and development to rainfall/runoff modeling using remotely-sensed inputs. Furthermore, the two of the proposers lived in Fort Collins for many years, have extensive hydrologic contacts in the area, and are intimately familiar with the region affected by the flood. It is anticipated that the initial analysis, modeling and re-creation of the flood can be performed in less than 3 months leading to a summary report and paper on the conditions leading up to, and during the event. Additional refinement and modifications of modeling efforts will continue until funding is expended. This initial effort will garner and focus national attention on the hydrometeorological conditions which lead to this storm, and establish the capabilities of physically-based, distributed-parameter runoff models using remotely-sensed rainfall input for predicting short-duration flash floods in urban areas. This new flash-flood modeling approach to be evaluated has significant potential to reduce the risk of life and property, as well as improve the accuracy of hydrologic design in urban areas.
