The Impact of Urbanization on Tropical Watershed Hydrology in Wushishi Using Remote Sensing Techniques.

Abstract

Future population growth and the corresponding increase in development the wushishi watershed are widely recognized as major threat to the integrity of watershed worldwide. The potential impact associated with the expansion of developed land, and specifically with increasing amount of impervious surfaces- rooftops, sidewalks, roads and parking lots- may include significant changes in water quantity degradation in water quality and habitat loss. Because asphalt, concrete, stone and other impermeable materials effectively seal the ground surface, water is repelled and is prevented from infiltrating the soils. Instead, storm water runoff flows directly into surface water, depositing metals, excess nutrients, organics and other pollutant into the receiving bodies. In addition to this environmental impact, increasing levels of imperviousness can dramatically alter our landscape, as forested and other natural settings are converted to urban/suburban uses. The primary goal of the project were to provide an accurate. Current description of the extent of impervious surface coverage in this region, as well as an estimate of change in the amount of imperviousness over a 14 years period (from 1987 to 2009). A detailed characterization of the watershed was also conduced. Geospatial technologies provides effective tool to map and quantify impervious surfaces, and monitor changes over time. Moderate resolution landsat thematic mapper satellite imagery, as well as image processing GIS software was utilized to estimate amount of imperviousness at relatively modest cost, thereby providing a mechanism for subsequently measuring “imperviousness” at frequent, repeated intervals. Resource managers and other professionals may effectively utilize the resulting data as they develop watershed management plan and tools