Multiparametric Ahp-based Flood Hazard Zonation Approach in Northwestern Peru at Basin Scale

Extreme rainfall events and consequently Floodings are phenomena in Peru with severe economic, social and environmental consequences when it occurs in several regions during summer or during El Nino (ENSO) phenomenon. Therefore, in several basins located in northwestern Peru, floods are a constant risk to people in urban, industrial or agricultural areas along rivers and floodplains. Extreme flood events in Piura river basin in recent decades, had huge economic and human impacts, added to an increase in population concentrations in critical flood risk zones. urban and rural environment. Against this already serious context, enhanced climate variability changes are expected to increase the frequency and intensity of floods in Peruvian Basins. This research aims to assess flood susceptibility through the application of an Analytical Hierarchy Process (AHP), using several flood conditioning factors related with basin morphology; terrain morphology; permeability; hydrography and finally rainfall provided from PISCO-SENAMHI gridded datasets (5km-5km) available in daily and monthly scales. All variables from remote sensing, field and geospatial processing were classified with scientific and pragmatic criteria as raster datasets at basin level with a resolution of 12.5x12.5 m cell size using ALOS PALSAR terrain information. This research will be an important tool for flood risk management to be conceived as a process with an integrated approach for adequate decision making on soil and water resources, showing that remote sensing and GIS products are also capable to deliver quite an accurate result, maximizing the net benefits of floodplains and minimizing losses. The resultant map shows critical areas with different susceptibility of flood, and these regions are requiring some serious attention of governmental or non-governmental offices to reduce the flood risk. The AHP process method proposed in this research can be easily applied to other basins around peruvian slope and coast for different ways of flood hazard management and prevention plans. Outlooks for the future of this research includes the integration of this AHP zonification at the municipal level, achieving local flood susceptibility indexes in order to verify the capabilities of flood control by natural constrains in districts or towns.