Clay Minerals Accelerating Gully Erosion in Wadi Isser Watershed, Northern Algeria, Mediterranean Region

The Wadi Isser watershed is a continental basin that is currently under severe water erosion. The Mediterranean climatic conditions and associated alterations have prevailed since the Early Quaternary and deposited clay-rich sediments. This study aims to determine clay minerals that accelerate gully erosion in Wadi Isser, northern Algeria. Mineralogical analysis by X-ray diffraction (XRD) was carried out for thirteen samples, which are representatives of different stratigraphic units of the Wadi Isser watershed that are subject to erosion. The results distinguish three behaviors of clay minerals, significant to gully erosion. Kaolinite, chlorite and illite are stable minerals and have no influence on erosive potential. Interstratified chlorite-vermiculite, vermiculite, interstratified illite-vermiculite and illite-smectite are water acceptors and smectite is swelling clay mineral. The water acceptors and swelling clay minerals accelerate the gully erosion