HR: 0800h
AN: H41D-0454    [Abstracts]
TI: Quantifying the Spatial Configuration of Impervious Cover and its Effect on Runoff Generation in the Whiteoak Bayou Watershed In Texas
AU: * Olivera, F
EM: folivera@civil.tamu.edu
AF: Texas A&M University, Department of Civil Engineering 3136 TAMU, College Station, TX 77843-3136 United States
AU: DeFee, B B
EM: defee@uamont.edu
AF: University of Arkansas at Monticello, School of Forest Resources 110 University Court, Monticello, AR 71656 United States
AB: This study examines the relationship between the developing landscape and the water flowing through it in the Whiteoak Bayou watershed located in the coastal plains in Harris County, Texas, on the northwest outskirts of Houston. The area was 223-km2 and the analysis period spanned from January 1, 1949, to December 31, 2000. Daily streamflow data for the 52 years was obtained from USGS and coincident precipitation data was obtained from NOAA. Georeferenced parcel-level land use data was obtained from the Harris County Appraisal District with sufficient detail to determine the parcel area, the year of development, and the building area. Watershed boundaries were obtained from the Harris County Flood Control District. The analysis of the flow series showed striking changes in the flow regime around years 1972 and 1985, which were not associated to changes in the somewhat steady increasing trend of the watershed total developed area or impervious cover. This study aimed at determining measures of development that could explain the flow regime changes in the Whiteoak Bayou watershed. As part of the analysis, geographic information systems (GIS) and spatial metrics were utilized to describe the changes in the broad-scale patterns of the human-developed portion of the landscape, and to relate them to changes in streamflow over time. FRAGSTATS was used to quantify spatial patterns in the developed landscape on an annual basis. It was found that models based on the spatial configuration of the developed landscape capture better the flow regime changes. In particular, it was found that the decline in the number of developed patches, caused by the filling of the gaps in the built areas, coincided with an identifiable increase in flow rates.
DE: 1819 Geographic Information Systems (GIS)
DE: 1834 Human impacts
DE: 1854 Precipitation (3354)
DE: 1860 Streamflow
DE: 1879 Watershed
SC: Hydrology [H]
MN: Fall Meeting 2005