ESTIMATION OF RESIDENTIAL IMPERVIOUS SURFACE USING GIS TECHNIQUE

Urban impervious surface in the form of rooftops, street pavement, parking lots, etc. is an important contributor to water pollution, urban heat island, flash floods and other environmental degradations. While studies on the extent of impervious surface are common in advanced countries, few have been carried out in developing countries. This paper discusses a study on the nature of impervious surface coverage in a southern city in Malaysia. The study focuses on impervious surface in several residential areas, looking at the relationship between impervious surface and housing density as well as the source of the surface. Remote sensing images combined with some GIS techniques were employed for this purpose. The percentage o[ impervious surface measured ranged from 40-95%, well above the values indicated from similar studies overseas. While density was a factor in the amount of impervious surface, it was not the only factor. Other factors such as policies on impervious surface control were also important as illustrated by comparison of the results of this study to similar studies reported in the USA. Based on these findings, the paper offersseveral steps towards reduction of impervious sw'face in residential areas.