The role of physical environment in the genesis and amplification of floods in Nador (Northeast Morocco)

Abstract

Northeast Morocco has experienced significant socio-economic changes that induce dramatic developments of urban areas and massive rural exodus. The urban growth processes are sometimes poorly controlled and occur on vulnerable areas. Nador is located on the bottom of Gourougou foothills where many streams converge. Flooding is recurrent phenomenon in this site. Several exceptional rainfall events and critical flow rates were recorded in the recent decades. Thus, Nador city located on a base level plain is potentially threatened by storms falling on too close steep slopes. The purpose of this study is identifying and mapping areas threatened by floods in Nador. The combination of different information layers dealing with land use, drainage network, slopes, lithology/geology and road network, using remote sensing and GIS tools provides vulnerability indicators and allows drawing a flood risk map. The objective is hazard causes understanding, to help early warning and to define the potential extent of flood in threatened urban areas.