Flood Susceptibility in the Lower Course of the Coyuca River, Mexico: A Multi-Criteria Decision Analysis Model

Flooding due to climate change is recurrent and has intensified in the lower course of the Coyuca River. This paper implements a multivariate analysis, including conditioning and triggering factors to develop flood susceptibility mapping in an information-deprived region to help prevent/mitigate flooding. Flood-susceptible areas were identified using the multi-criteria decision analysis (MCDA) methodology, specifically, with the hierarchy analysis process (AHP). Four conditioning and one triggering influence factors were analyzed. The influence weights of each variable were determined using Saaty's methodology (AHP). Thematic maps for each variable were created and multiplied by their influence value using the raster calculator and added to their variable group to obtain the flood susceptibility map. The findings showed that the susceptibility to flooding was very high in 41.82%, high in 35.95%, medium in 21.25% and low in 0.98% of the study areas. It was revealed that 44.44% of the localities occupy areas of very high susceptibility to flooding. Susceptibility increases in the localities closest to the river.