A PROPOSAL OF GIS BASED FEATURE ORIENTATED LAND USE DATA MODEL FOR URBAN RUNOFF ALALYSIS

Abstract

Recently, Geographic information data such as Digital Elevation Model is available in runoff analysis because of improvement of GIS (Geographic information system). In particular, various hydrological models have made a proposal based on DEM. However, there has been least study on land use model that is the origin of flow generation. Subcathments in slope element runoff model or grids in distributed hydrological model are subdivided into impervious area and pervious area from land-use data. Effective Precipitation is calculated based on them as the specific value in the region. Using the land-use data, there is a problem that the position of runoff control equipment doesn't reflect the runoff model in detail. It is unable to set Equipment characteristic value (discharge point, equipment scale), because land-use model and equipment dose not have one to one correspondence. In this study, hydrological model using polygon format data to express land-use is proposed, and applied to Kotta River basin. The simulated hydrograph show relatively good agreement with the observation.