Assessment And Modeling Of Flood Risk In The Municipality Of Tamazoura (Algeria): Delineation Of The Public Hydraulic Domain And Prevention Strategies For Exceptional Flood Events
DOI:
https://doi.org/10.64252/psdn0q18Keywords:
Flood phenomenon ,Tamazoura, ,Algeria, Hydraulic modeling ,HEC-RAS, Overflow risk, Public hydraulic domain (DPH), Law No. 05-12Abstract
The flood phenomenon in Algeria is ranked second after earthquakes in terms of human and material damage. Given the multiple years of drought, especially in western Algeria, the wadis have lost their major beds (the flood zones). This is due to the harmful actions of citizens and public authorities (legal and illegal housing). The municipality of Tamazoura is one of the agglomerations threatened by the flood phenomenon. This risk was studied in order to avoid potential human and material damage and to delimit the flood zone used to determine the public hydraulic domain (the limits of the major bed of the Oued Tamazoura). A consistent hydrological study was established after recovering rainfall data from three neighboring stations (Tassala station, Es-Sania, and Tamazoura). At the end of this part, we were able to develop flood diagrams (20, 50, 100, and 1000 years). Given the importance of the Tamazoura watershed and the absence of storage areas upstream of the wadi, our study is based on the two exceptional floods of 100 and 1000 years. The hydraulic modeling is performed using the HEC-RAS calculation code (6.3.1). Our modeling is based on fairly reliable data, namely the topographic survey of the wadi and the DTM of the study area. A field survey was the foundation for developing the roughness map of the site. This survey allowed us to calibrate the simulation results by recovering the maximum levels of past exceptional floods. Several maps were produced to better exploit our results (floodplain map, water depth map, water velocity map). At the end of this study, we came to two relevant conclusions: firstly, the risk of overflow is strongly present in the city center. Secondly, we have managed to draw up a map of the flood zone, which will be a solid support for local authorities to delimit the public hydraulic domain of Oued Tamazoura (DPH), as required by Law No. 05-12 of August 4, 2005.