HR: 1340h
AN: H43D-1614    [Abstracts]
TI: Predictive Modeling of Urbanization Impacts on Flow Regimes in a Semi-arid Watershed in Southern California
AU: * He, M
EM: kevinhe@ucla.edu
AF: UCLA, 5732C Boelter Hall Department of Civil and Environmental Engineering, Los Angeles, CA 90095-1593, United States
AU: Hogue, T S
EM: thogue@seas.ucla.edu
AF: UCLA, 5732C Boelter Hall Department of Civil and Environmental Engineering, Los Angeles, CA 90095-1593, United States
AB: In semi-arid southern California, large areas of vegetative land cover are disappearing due to rapid and extensive urbanization. The anthropogenic process paves natural land surfaces, altering the partitioning of precipitation, and subsequently affecting regional hydrologic processes and water supply. This research aims to improve the understanding of the impacts of urbanization in semi-arid watersheds. We focus our efforts on the Upper Santa Clara River basin in northern Los Angeles County which is undergoing rapid transition from a natural state to an urbanized state. The Hydrologic Simulation Program-Fortran (HSPF) model has been parameterized with the land use, soil, and channel characteristics of the study watershed. Model parameters related to hydrologic processes are calibrated at the daily time-step using both lumped and distributed precipitation inputs, respectively, over a six-year period. Calibration results from lumped inputs indicate that model performance is reasonable during wet years and wet seasons, but is less satisfactory in dry years and dry seasons. Model calibration with distributed inputs is ongoing. Potential urbanization scenarios are generated by assigning various percentages of developed area in the watershed. Hydrologic processes under each scenario are simulated via the calibrated model. Simulation results and discussion on the hydrologic impacts of urbanization in this rapidly expanding watershed will be presented.
DE: 1821 Floods
DE: 1847 Modeling
DE: 1860 Streamflow
DE: 1879 Watershed
SC: Hydrology [H]
MN: 2007 Fall Meeting