Contribution of Remote Sensing and GIS to the Morphometric Assessment of the Abéché Watershed, Chad

Abstract

The various morphological parameters of watersheds play a crucial role in determining their hydrological behavior. The analysis of morphometric parameters is the fastest and most economical way to represent the hydrological and physiographic characteristics of watersheds. This study uses GIS and remote sensing to determine morphometric parameters in order to assess the understanding of physiographic, morphological, and hydrographic properties. The parameters were analyzed using a digital elevation model (DEM) combined with Excel software. A total of thirteen parameters (Gravelius Compact, Shape factor, hypsometric curve, soils, average elevation, Equivalent rectangle, Average slope index, Total elevation difference, Overall slope index, Specific elevation difference, Drainage density, River frequency, Concentration time) were determined to assess the various characteristics of the Abéché watershed. The values of the relief parameters show that the watershed has a steep relief (382 m). The density of the hydrographic network indicates a very coarse nature (1.16 km) and represents an elongated shape. The hypsometric curve shows that the Abéché watershed is at a mature stage of formation. These results would be useful for evaluating watersheds for drainage management and environmental planning for sustainable management and development.