Impacts of Urbanization on Peak Flow Using Remote Sensing
- Author(s): Dingman, John
- et al.
The eastern edge of San Ramon, California, close to the Dublin border, is undergoing considerable residential development. Work in this area began at a development called Windemere in 2001 with the first homes being available for sale in 2002. The population, along with the number of housing units, in San Ramon has increased. I suspect housing developments are impacting the volume of water in the streams which may increase the risk of flooding. I compared the impacts of urbanization on stream peak flow in two neighboring drainage basins, the Alamo Creek and Tassajara Creek. Using 28 meter six band Landsat Imagery (landsat.usgs.gov), I measured Alamo Creek drainage basin and found it consists of 32 percent developed land area while the Tassajara Creek drainage basin is 6 percent developed land area. I made this determination using a maximum likelihood classification algorithm to delineate developed areas from non-developed land. I used the Rantz Method, to calculate the peak flow for 2, 10, 25, and 50 year return intervals for the two drainage basins. At the catchments of the two drainage basins, I conducted cross-sectional profiles, and recorded high water marks. I calculated peak flow from the high-water marks using the Manning’s equation.