Environmental sensitivity of flash flood hazard using geospatial techniques

Flash flood has been increasing in the Khartoum area, Sudan due to geographical conditions and climatic change as heavy rainfall and high temperature, therefore the present work tried to estimate the sensitivity of flash flood. The present work proposes an advanced technique of flood sensitivity mapping using the method of analytical hierarchy process. Ten factors as elevation, slope, distance from the network, land use, density of the drainage, flow accumulation, surface roughness, stream power index, topographic wetness index and curvature of the topography were digitized and then contributed in the mapping of Flash flood. Remote sensing data were integrated with analytical hierarchy process to determine the flood sensitive area in Sudan. The model was applied and completed as the consistency ratio was mostly reasonable (< 0.1). Based on the proposed model, about 75.56 Km2 (12.26 %), 156.14 Km2 (25.33%), 169.89 Km2 (27.56 %), 141.40 Km2 (22.94 %) and 73.50 Km2 (11.92 %); were classified as no susceptible, low susceptible, high susceptible, moderate susceptible and very highly susceptible to flooding. The present study showed a high variation in flood sensitivity due to climatic change and geographic condition. This index can be modified and applied in areas of the same characteristics of climatic conditions as one of the main recommendation in the study area. The study showed that poor infrastructure and lack of preparedness were the main causes of the disaster of flood in Sudan. This study merely demonstrated the critical analysis of geospatial mapping in proper mitigating, sustainable development and great monitoring the negative effects of flooding along the Khartoum region to reduce hazards of flood. 

Keywords:

Analytical Hierarchy Process (AHP) , Disaster , Flash flood , Remote sensing (RS) , Shuttle radar topography mission- Digital elevation model (SRTM-DEM)