Spatial Modelling of Soil Conservation Service Curve Number Grid and Potential Maximum Soil Water Retention to Delineate Flood Prone Areas: A Case Study

摘要

The Soil Conservation Service Curve Number (SCSCN) is a hydrological parameter used to describe storm water runoff potential for drainage areas and it is a function of Landuse, Hydrological Soil Groups (HSGs) and Digital Elevation Model (DEM). This study described how to estimate the SCS CN and Potential Maximum Soil Water Retention (PMSWR) to delineate flood prone areas. The study was carried out in the Accra Metropolitan Area which lies in the dry savannah coastal zone of the southern part of Ghana and is approximately 5° 33' 00" N of the Equator and 0° 12' 00" W of the Greenwich Meridian. The HSGs, Land use and DEM were used to generate the SCS CN and the PMSWR of the study area. The results of the SCS CN, PMSWR and slope maps indicated areas with high runoff potential and areas prone to flooding during storms. This study proved that the PMSWR and SCS CN values are important hydrological parameters to determine areas of high runoff potential and thus delineating flood prone areas.