HR: 1330h
AN: H12B-0990    [PDF]
TI: Modeling hydrologic processes at the residential scale
AU: * Xiao, Q
EM: qxiao@ucdavis.edu
AF: Hydrologic Sciences, Dept. LAWR University of California Davis, Davis, CA 95616
AU: McPherson, G
EM: egmcpherson@ucdavis.edu
AF: Center for Urban Forest Research, Dept. Env. Horticulture University of California Davis, Davis, ca 95616
AU: Simpson, J
EM: jrsimpson@ucdavis.edu
AF: Center for Urban Forest Research, Dept. Env. Horticulture University of California Davis, Davis, ca 95616
AU: Ustin, S
EM: susan@cstars.ucdavis.edu
AF: Hydrologic Sciences, Dept. LAWR University of California Davis, Davis, CA 95616
AB: In California, urbanization has led to polluted runoff, flooding during winter, and water shortages during summer. There is growing interest in application of microscale hydrologic solutions that eliminate storm runoff and conserve water at the source. In this study, a physically-based numerical model was developed to better understand hydrologic processes at the residential scale and the interaction of these processes among different Best Management Practices (BMPs). This model calculates all in-flow and out-flow using an hourly interval over a full year or for specific storm events. Water enters the system via precipitation and irrigation and leaves the system via evapotranspiration, surface and subsurface runoff, and from percolation to groundwater. The model was applied to two single-family residential parcels in Los Angeles. Two years of data collected from the control and treatment sites were used to calibrate and validate the model. More than 97% of storm runoff to the street was eliminated with installation of low-cost BMPs (i.e., rain gutters that direct roof runoff to a lawn retention basin and a driveway interceptor that directs runoff to a drywell in the lawn retention basin). Evaluated individually, the driveway interceptor was the most effective BMP for storm runoff reduction (65%), followed by the rain gutter installation (28%), and lawn converted to retention basin (12%). Installation of an 11 m3 cistern did not substantially reduce runoff, but did provide storage for 9% of annual irrigation demand. Simulated landscape irrigation demand was reduced 53% by increasing efficiency through use of a drip irrigation system for shrubs, and adjusting monthly application rates based on evapotranspirational water demand. The model showed that infiltration and surface runoff processes were particularly sensitive to the soil's physical properties and its effective depth. If the existing loam soil were replaced by clay soil annual runoff discharge to the street would be increased by 63% when climate and landscape features remained unchanged.
UR: http://cufr.ucdavis.edu
DE: 1842 Irrigation
DE: 1857 Reservoirs (surface)
DE: 1860 Runoff and streamflow
DE: 1884 Water supply
SC: Hydrology [H]
MN: 2003 Fall Meeting