Integrating Analytical
Hierarchy Process and Geographical Information Systems for Comprehensive Flood Risk
Evaluation in Upputhara, Kerala
Nair Arun G. and Suresh S.
Disaster Advances; Vol. 18(8); 48-59;
doi: https://doi.org/10.25303/188da048059; (2025)
Abstract
Floods are among the most common and costly natural hazards worldwide, significantly
impacting the environment by affecting water quality, biodiversity and increasing
pollution levels. Upputhara, located in the Idukki district of Kerala, experiences
frequent flooding due to its location in a V-shaped valley of the Periyar river,
just below the Mullaiperiyar and Idukki reservoirs. The primary aim of this study
is to delineate a flood hazard map for the Upputhara Grama Panchayat using a geospatial-based
Analytical Hierarchy Process (AHP). The data sources for this study include Survey
of India (SOI) topographical maps, ASTER DEM (30-meter resolution) and rainfall
data from the Indian Meteorological Department (IMD). The flood hazard map was generated
using nine spatial layers: vegetation condition, rainfall, geology, elevation, flow
accumulation, topographic wetness index, drainage density, slope and soil texture.
The final map was produced through multi-criteria overlay analysis within a GIS
environment, classifying the area into five flood hazard categories: very low (52%),
low (28%), moderate (13%), high (5%) and very high (1.5%). Field data from flood-affected
locations showed that the model has a 95% accuracy. While the majority of the study
area faces a very low to moderate flood risk, about 17% of the region is at high
to very high risk. This study demonstrates that geospatial technology-based flood
hazard delineation is highly effective and supports sustainable development and
planning. The generated map aids authorities responsible for flood protection by
raising awareness about flood-prone areas and helping to reduce vulnerability.
