Applications of Geoinformatics for Flood Hazard Zonation - A case study of Pozhuthana grama panchayath, Wayanad district, Kerala

Floods are among the most frequent and destructive natural disasters globally, posing significant threats to both human lives and infrastructure. The increasing population density in flood-prone areas, unplanned urban development, and encroachment into natural floodplains have intensified the vulnerability of many communities. This study aims to delineate flood-prone areas within Pozhuthana Grama Panchayath, located in Wayanad district, Kerala, using remote sensing and Geographic Information System (GIS) techniques. The analysis is conducted through a weighted sum overlay method, incorporating multiple thematic layers including slope, elevation, drainage density, rainfall, geology, geomorphology, soil type, and land use land cover. These layers, processed in the ArcGIS environment, were derived from satellite data and secondary sources. The outcome of this analysis is the Flood Hazard Zonation (FHZ) Map, which classifies the region into four distinct flood risk zones: low, moderate, high, and very high. To validate the accuracy of the FHZ map, a comparison was made with past flood events, particularly the 2018 Kerala flood. The comparison indicates that most of the areas falling under the mapped high and very high-risk zones in the map correspond with regions affected during past flood events. A spatial comparison with previous flood events, particularly the major Kerala floods, confirms that most high and very high-risk zones were indeed affected, validating the accuracy of the model. This study can guide land use planning, infrastructure development, and emergency preparedness, contributing to more resilient communities in flood-sensitive regions like Pozhuthana Grama panchayath.