Morphometric analysis of river subwatersheds using geographic information system and principal component analysis, northeast of Algeria

Abstract

In the present paper an attempt is made to study the morphometric characteristics of five watersheds which are part of Seybouse and Coastal basin of Constantine located in northeast of Algeria. The study focuses on evaluating the effect of morphometric parameters on land degradation. The Geographical Information Systems which represent efficient tools in determination of drainage basin morphometric properties and principal component analysis are applied to ten geomorphic parameters on twenty subwatersheds, to group the parameters under different components based on significant correlations. Some morphometric parameters are computed and analyzed such as basin area, drainage density, stream frequency, form factor, orographic coefficient, hypsometric integral, and lithology index, basin slope, average overland flow distance, basin relief ratio. Outcomes of the matrix of correlation and principal component analysis of ten geomorphic parameters clearly depict that fifty percent of the variables are strongly correlated with the components like basin area, drainage density, stream frequency, orographic coefficient and relief ratio. It has been found that Guis sub-basin, three sub-basins of the Saf Saf watershed and all the sub-basins of the Mellah watershed are subjected to high land degradation, thus, creating an urgent need for applying soil and water conservation measures.