Flood Hazard Zonation -A GIS aided Multi Criteria Evaluation (MCE) Approach with Remotely Sensed Data

要旨

To meet a specific objective, it is frequently the case that several criteria will need to be evaluated. Such a procedure is called multi-criteria evaluation (MCE). A study using GIS aided multi-criteria evaluation approach in flood hazard zonation was described in this paper. Bogra district of Bangladesh was selected for this study. The main objective of this study was to develop a flood hazard zone map of the study area with selected eight criterions viz. water level rise flood zone, flood return period, probability of flood occurrence, flood depth, observed flood frequency, population density, runoff potential and rainfall along with MCE technique. To generate necessary layers (Factors and Constraints) for the MCE approach, remote sensing and GIS integrated techniques and models were applied. To standardize the factors and establishing the factors weight for the MCE, analytical hierarchy process (AHP) method was used in this study. Finally to perform the multi-criteria evaluation (MCE) for flood hazard zonation, MCE module of IDRISI software was used. The results depicted that about 17.14% and 20.08% of the total area is classified under very high and high flood hazard zone respectively and 35.36% of the total area is found to be the least vulnerable (low to very low hazard zone) to flood hazard. On the other hand, Dhunat, Adamdighi and Gabtali thanas are the most vulnerable in respect to flood hazard in the study area. So, this study reveals that MCE technique can be utilized advantageously and effectively for flood hazard zonation in a flood prone area.