Mapping of soil degradation and vulnerability in the Noun Syed watershed by water erosion: what impacts of climate change approach by remote sensing and GIS

Résumé

The watershed of Oued Seyad is located in the South of Morocco, it is a structured basin in pleated Bani, crowned by the quartzitic bars of the Ordovician and the limestone plateau of the Akhsass. The study area has an arid climate and presents the characteristics of Mediterranean desert landscapes vulnerable to soil degradation processes. The Seyad watershed is characterized by the confluence of two wadis: Kelmt and Ifrane.

 Water erosion is the main threat of soil degradation in this basin, causing different phenomena in relation to climate change. It usually causes severe flooding and agro-soil damage, both upstream and downstream.

The objective of this study is to characterize the vulnerability of the soil, to quantify and map in support of spatial remote sensing; the intensity of the risk of water erosion and the regressive soil dynamics following climate change.

 The approach followed is based on the use of remote sensing and GIS data to map, assess and analyse the major factors involved in the erosive process (precipitation, vegetation cover, soil erosion, topography and anti-erosive practices) and their integration into the revised universal soil loss equation. The results obtained from field studies show the high susceptibility to the risk of water erosion in recent years.