Download This PaperFlood Risk Assessment in Saharan Regions. A Case Study (Bechar Region, Algeria)|JBES
Journal of Biodiversity and Environmental Sciences (JBES), Vol. 16, No. 1, p. 42-60, 2020
19 Pages Posted: 1 May 2020
Date Written: Jan 30, 2020
Abstract
Intensive storm rainfall induced flooding is one of the most severe and devastating natural disasters in arid regions. In recent years, urban expansion and consolidation, changing demographic features within floodplains makes the urban environment transformed dramatically and results in additional flood risks. In this research, Gumbel’s distribution was used to analyze maximum daily precipitation data from 1963 to 2012 (49 year) and calculate maximum instantaneous flows with different return periods, namely, 2-, 5-, 10-, 20-, 50-, 100-, and 1000-year. The peak flows from precipitation frequency analysis were input into the hydraulic models (HEC-RAS) to find the corresponding flood extents in a study area located in the upstream of Bechar basin. The results from HEC-RAS model were then used in integration with ArcGIS to compile a floodplain maps. Flood extents through floodplain maps, areas that are vulnerable to flooding hazards have been identified. Floodplain map analysis indicated that 2.679km2 with the percentage of 23% is likely to be flooded under 100 year return period flood. In addition, show that the traffic roads and buildings surroundings Ephemeral river are more susceptible to flooding. Based on the results of this analysis, assist planners and policy makers can develop an effective strategy of flood management related to Ephemeral River overflowing through Bechar city.
Keywords: Precipitation, Frequency analysis, Flood extents, Ephemeral river
Suggested Citation: Suggested Citation