Coastal vulnerability assessment using Geospatial technologies and a Multi-Criteria Decision Making approach - a case study of Kozhikode District coast, Kerala State, India

摘要

Climate change-induced marine hazards are increasingly threatening coastal zones, with a two-fold increase in the last decade. In this study, we assessed coastal vulnerability using the multi-criteria decision making (MCDM) method in conjunction with geospatial applications. Data on five physical variables: geomorphology, coastal slope, shoreline change history, spring tide range and significant wave height were extracted from the optical and microwave remote sensing images, existing maps and GIS processing for the 78-km-long coastal zone of Kozhikode district, which was taken as a case study. Weighted analysis of these variables and their subunits was performed using the analytical hierarchical method. These data were then processed to calculate the coastal vulnerability index (CVI), which ranged between 0.06 and 0.44 for the study area with higher CVI values indicating higher risk of hazards. The coastal risk analysis made using the geometric interval classification of the entire range of CVI values indicated that more than a third of the Kozhikode coast is under high risk to coastal hazards. Our study demonstrated the importance of integrating geospatial and MCDM analysis for a robust coastal vulnerability assessment in determining the hazard proneness of different coastal segments.