Estimation of Runoff Depth Using GIS Maps and Soil Conservation Service-Curve Number Method in AL-abrash Basin in Syria

Abstract

Accurate estimation of runoff depth is an important aspect for proper watershed management. Runoff depends on the intensity, duration, distribution of rainfall and on soil type. Vegetation and land use types have significant effects on the runoff. The aim of the present study is to determine the runoff depth and its distribution in AL-abrash basin in Tartus province of Syria using Soil Conservation Service-Curve Number (SCSCN) method and remote sensing data from October 2017 to May 2018. Land use/land cover and soil texture maps of the study area were prepared in geographic information system (GIS) environment and using remote sensing software (e.g. ERDAS IMAGINE). Annual amount of runoff was high in the western and southwestern part of the study area, which may be due to heavy soil type. Depth of runoff in the study area was between 250 and 400 mm. While the amount of runoff declined in the eastern part of the study area due to either the soil type (sandy loam, sandy clay loam) or the nature of the ground cover (forest, olive groves) which prevented the surface runoff significantly. Key words: Runoff, remote sensing, soil texture, curve number, rainfall.