Prioritization of sub watersheds based on hydro morphometric analysis in the Sankarani watershed, upstream tributary of the Niger River

Abstract

Any hydrological study of watersheds requires morphometric analysis. This analysis is a powerful tool in watershed management (Biswas et al., 1999, Yasmin et al., 2013). Climate change coupled with land-use changes raises development issues, including the availability of water resources for people's needs. Faced with these ever-increasing needs of the population, land development becomes a requirement. Thus, the objective is to analyze the morphometric characteristics of the Sankarani basin in order to prioritize its sub-basins. To this end, the satellite images of the digital terrain model (DTM) of the SRTM (30mx30m) type of 2012 were used. Under the Grass GIS open source program, five sub-basins (BV1-I, BV2-M, BV3-Y, BV4-G and BV5-S) have been delimited. The measured parameters are the number of rivers and their classifications, to define the geometry of the basin (area, perimeter, length), the various indices (drainage density, slope ratio, texture ratio, elongation ratio and ratio of form factor) and to determine hypsometric curves. The hierarchy was performed by assigning ranks to the individual indicators and a compound parameter (Cp) value was calculated. The method established that BV2-M (upstream) has the highest priority of the other sub-basins of Sankarani for land conservation actions and the sustainable management of water resources.