HR: 1400h
AN: H53B-10    [Abstracts]
TI: Developing Methodologies for Applying TRMM-Estimated Precipitation Data to Hydrological Modeling of a South TX Watershed - Initial Results
AU: * Tobin, K J
EM: ktobin@tamiu.edu
AF: Texas A&M International University, 5201 University Blvd, Laredo, TX 78041, United States
AU: Bennett, M E
EM: mbennett@tamiu.edu
AF: Texas A&M International University, 5201 University Blvd, Laredo, TX 78041, United States
AB: Previous experience with hydrological modeling in South Texas, which is located along the Texas-Mexico border, suggests that NWS ground measurements are too widely scattered to provide reliable precipitation input for modeling. In addition, a significant fraction of the study region is located at the edge of the coverage envelopes of the NWS NEXRAD weather radars present in the region limiting the accuracy of these systems to provide reliable precipitation estimates. Therefore, we are exploring whether TRMM estimated-precipitation data (3B42), in some form, can be used to support hydrological modeling in the Middle Rio Grande and Nueces River Basin watersheds. We have begun our modeling efforts by focusing on the middle Nueces watershed (7770 sq km). To model this largely rural watershed we selected the Soil and Water Assessment Tool (SWAT). Three precipitation datasets were selected for our initial model runs that include: (1) nearest NWS cooperative hourly rain gauge data, (2) three hourly TRMM 3B42 estimated precipitation, and (3) combination TRMM 3B42/NWS rain gauge datasets in which ground measurements are used for three hourly periods lacking high quality satellite microwave precipitation estimates as determined from TRMM 3G68 data. Three dataset were aggregated into an average daily estimate of precipitation for each TRMM grid cell. Manual calibration of was completed achieving model results that yield realistic monthly and annual water balances with both gauge and satellite estimate precipitation datasets. In the future, we plan to use the newly developed automatic calibration routine for SWAT, which is based on the Shuffled Complex Evolution algorithm, to optimize modeled discharge results from this study.
DE: 1804 Catchment
DE: 1824 Geomorphology: general (1625)
DE: 1853 Precipitation-radar
SC: Hydrology [H]
MN: 2007 Joint Assembly