Assessment of the vulnerability of coastal agriculture to seawater intrusion using remote sensing, GIS, and Multi-Criteria Decision Analysis

The Philippines heavily relies on crop production, with a significant portion cultivated in coastal agricultural areas. However, these farmlands are impacted by salinity intrusion, which adversely affects agricultural productivity. This study assessed the coastal agricultural barangays in Kalibo (Aklan, Philippines) using the exposure, sensitivity, and adaptive capacity indicators, and following the Intergovernmental Panel on Climate Change (IPCC) framework. It aimed to enhance local and national stakeholders' understanding of vulnerability to seawater intrusion. Physical, agroecological, and socioeconomic parameters were used as indicators, with weights determined through the Analytic Hierarchy Process (AHP). Various aggregation methods were used, and datasets from participatory methods and remote sensing technologies, including LiDAR, were integrated to evaluate vulnerability on a 500 x 500-meter grid. The assessment focused on coastal barangays selected by local officials and agricultural experts. Caano was the most vulnerable, while Bachaw Norte was the least. The exposure map highlighted Nalook, Estancia, and Caano as areas with the highest levels of exposure. The results were compared with the knowledge of city agricultural experts. A sensitivity analysis was conducted to assess the model for exposure indicators. This research contributes to planning and management approaches in Kalibo and advances knowledge of critical indicators in addressing the current challenges.