HR: 1340h
AN: H13H-1401    [Abstracts]
TI: Paired Catchment Modeling Study for a Monsoon Flood Event in Neighboring Semi-Arid Basins, New Mexico
AU: * Wyckoff, R L
EM: rwyckoff@nmt.edu
AF: Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 United States
AU: Vivoni, E R
EM: vivoni@nmt.edu
AF: Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 United States
AB: Flooding in ephemeral stream networks can significantly impact channel geomorphology, sediment transport, biogeochemical cycles, and water availability for consumptive and recreational use. In order to better understand the spatial patterns of flooding, distributed models may provide an opportunity for further investigation of rainfall-runoff dynamics in headwater semi-arid catchments including flood generation in ungauged portions of a watershed. For example, the R¡o Puerco in west-central New Mexico is an ephemeral tributary of the R¡o Grande spanning approximately 18,896 km² with mountainous forests to the north and semi-arid desert to the south. In mid-September 2003, a series of late monsoonal storms traversed the northern extent of watershed resulting in a flood pulse which propagated through the main reach of the catchment and into the R¡o Grande thereby substantially influencing streamflow as far south as Elephant Butte Reservoir (289 km). Radar data suggests flooding most likely emanated from two neighboring sub-catchments within the upper reaches of the watershed. In order to better understand the source of significant hydrologic events within the catchment, we utilize a fully distributed model to simulate the flood within the gauged Upper R¡o Puerco Watershed (1119 km²) as well as the immediately adjacent but ungauged Torreon Wash (1344 km²). The TIN-Based Real-time Integrated Basin Simulator (tRIBS) prioritizes interactions between the vadose and saturated zone through the simulation of downward moving infiltration fronts and a variable groundwater surface. Topography is captured through a multiple resolution triangular irregular network (TIN) which accurately represents changes in elevation and simultaneously diminishes the model's computational demands. In addition to faithfully modeling topographic features, tRIBS requires accurate representation and calibration of soil, land use features, and geomorphic data. Calibration is performed through a manual procedure in which parameter values are adjusted in an effort to match an observed stream hydrograph with the model output for a series of storm and inter-storm periods. Following model calibration, we transfer the parameter set to the neighboring Torreon Wash. Model results for the paired catchment study demonstrate the appropriateness of parameter transfer between two neighboring semi-arid catchments.
DE: 1817 Extreme events
DE: 1846 Model calibration (3333)
DE: 1853 Precipitation-radar
DE: 1874 Ungaged basins
DE: 1879 Watershed
SC: Hydrology [H]
MN: Fall Meeting 2005