Cinq Continents (Nov 2014)
Méthode d'analyse statistique de données morphométriques : corrélation de parametres morphométriques et influence sur l'écoulement des sous-bassins du fleuve Sénégal
Abstract
Statistical analysis of morphometric data Method : correlation of morphometric parameters and influence on the runoff of sub - basins of the Senegal River Basin . This article has analyzed the correlation between morphometric parameters and their influence on the hydrology of the Senegal River Basin. The abundance or the shortage of superficial water resources, at times, in an overturning pond, are closely linked to characteristics it surface, its morphology, the weather conditions of which it benefits (ETP, rain, etc.), the importance of aquifers and sup erficial formations, etc. Its orientation as well as its exhibition in the wet air masses and in the disrupted flows (depressions, etc.) are also determining factors. The pond overturning of the Senegal River is a hydrosystem of the wet tropical domain in its southern part and dry in its northen part the heights of which vary from 15 m (Bakel: median course) to 1330 m (Fouta Djallon); height averages approximately 672 m [1] . In the pond upstream to Senegal and to Mali, the heights of rain are raised (> 1800 mm / year to Mamou), the strong slopes and the rocks altogether little permeable. The part downstream and northern (zone of Bakel), is directed northward, then the West. It presents slopes ( slope index = 0.022 %) and less important heights (minimum height = 15 m ) . The rain is there low (~ 500 mm to Bakel). Among all the noted differences between ponds of Senegal, those so colled morphological, allowed us to classify in 2 (on axes I - III), 3 (on axes I - II) and 4 (on axes II - III) group from an analysis in main component. ACP results indicate the surface, the perimeter, the coefficient of compactness of Gravelius, and the width as main parameters of this subdivision. These factors are also the most correlated in the flow of combining ponds. On these bases, it is possible to draw the limits between various physical sets by grouping ponds hillsides belonging to the same geomorphologic unity.
