Using volunteered geographic information data for flood mapping – Wadi Deffa El Bayadh Algeria

Abstract

This study presents a coupled application of hydrological and hydraulic models to reconstruct a flash flood event of the ungauged watercourse of Wadi Deffa, Algeria. The objective is to compare the performances of three hydrological models (rational method, EBA4SUB, HEC-HMS) and two hydraulic bidimensional models (HEC-RAS 2D, FLO-2D) by using the Volunteered Geographic Information (VGI) data. The comparison between the observed and simulated flood areas showed satisfactorily performance of the EBA4SUB-FLO-2D approach compared to the other approaches. The analysis of the observed and simulated flood depths showed a good estimate using the approaches EBA4SUB-FLO-2D and EBA4SUB-HEC-RAS 2D. The best estimate of the two flood depth approaches is attributed to the hydrological model EBA4SUB in estimating the peak flow. The results demonstrate that the EBA4SUB-FLO-2D modeling approach can provide reliable data for the management of flood risks in the ungauged watersheds of the southwest region of Algeria.