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Geomorphological dynamics of the Mlames Wadi (Central Tunisia) Volume 18, issue 3, septembre 2007

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Author
Département de géographie, Faculté des lettres et des sciences humaines de Sfax, BP 553, 3000 Sfax, Tunisie

This work is devoted to studying one the endoreic wadis of the lower steppes which discharges into the Sidi al Hani sebk during periods of rising. The whole of this wadi’s watershed is currently undergoing obvious transformation of its landscape due mainly to the interaction between the physical characteristics of superficial deposits, climatic risks and human actions. Study of the wadi’s geomorphological dynamics was based on photo-interpretation validated by field work. The aerial coverage viewed, going back to the years 1948, 1963 and 1993, enabled us to follow the evolution of this wadi before and after the cooperatives period, the 1969 flood and finally after the installation of Water and Grounds Conservation work (beginning of the nineties). The follow-up of the erosive processes in action (retreat of the valley head, collapse and undermining of the banks, suffosion) showed that the Mlames wadi’s effluents react differently. These differences are due to the fact that human activities do not intervene at the same rhythm throughout the wadi’s watershed. Such activities appear in the installation of Water and Grounds Conservation work and in cultivation methods with the introduction of heavy techniques. Their impacts are mainly reflected in the form of the wadi’s bed.