Morphometric analysis of the Soummam basin using remote sensing and GIS technologies

Abstract

<p>Morphometric analysis is a quantitative description and measurement of landforms. it has an important role in understanding the quantitative geomorphology of a drainage basin across the linear, areal, and relief aspects. Geographical Information System (GIS) and remote sensing technologies are effective in the determination of the morphological characteristics of the basin and make the process of analysis easier than traditional methods. Morphometric analysis is crucial for watershed planning, it reveals pieces of information about soil condition, soil erosion, sediment yields, and water storage capacity, and it also indicates important information concerning the incidence of infiltration, runoff, and flood. The main objective of this study is to assess the morphometric characteristics of the Soummam Basin which is considered one of the most important hydrological areal units in Algeria based on the Digital Elevation Model (ASTER DEM 30m) using Qgis. Morphometric parameters included for this study are: Stream order, stream number, stream length, bifurcation ratio, basin area, stream frequency, form factor, circularity ratio, elongation ratio, drainage density, drainage texture, ruggedness number, constant of channel maintenance, infiltration number, basin relief, and relief ratio. We discussed the affecting factors and the hydrological implications for each one of these parameters for the Soummam basin, its two Sub-basins Sahel and Boussellam, the Ain Zada dam catchment within the Boussellam sub-basin, and the 9 sub-catchments that discharge in the Ain Zada dam catchment with a comparative analysis of these drainage basins. The Soummam basin was designated a seventh-order basin when its two sub-basins had the 6th order and for the sub-catchments that discharge in Ain Zada dam the order of the drainage basin varies from 5th order to 3rd order. The drainage density results were low which indicates that the study area deal with a run-off possesses dominated by infiltration and sub-surface flow, a high permeability, and a dense vegetation cover with a low intensity of rainfall. Form factor, elongation ratio, and circularity ratio results accorded an elongated shape for most of the drainage basins, elongated basins have low pick flow with longer duration. Infiltration numbers results indicated a high infiltration rate and a low run-off. These results are useful for watershed prioritization, and mapping the groundwater recharge potential zone, and they indicate the importance of groundwater potential in the study area, also they can provide scientific material for flood management, water storage, and soil erosion for better watershed management & efficiency better sustainable watershed plan which aim to conserve natural resource</p>