Assessing the Vulnerability of Agricultural Crops to Riverine Floods in Kalibo, Philippines using Composite Index Method

Abstract

Evaluating the vulnerability of a system can serve as an effective planning tool in increasing resilience to a certain hazard. In this study, a vulnerability assessment of agricultural crops to river flooding in Kalibo, a municipality in Aklan, Philippines, was performed. The analysis included physical, agro-ecological, and socio-economic indicators clustered under the components of exposure, sensitivity, and adaptive capacity. Indicators relevant for a composite index measuring degree of vulnerability to flooding were identified and corresponding weights were determined using Analytic Hierarchy Process (AHP). Various datasets were acquired using Light Detection and Ranging (LiDAR) remote sensing and participatory methods such as focus group discussions (FGDs) and key informant interviews (KIIs). The barangay-level (village-level) and gridded (500m x 500m) vulnerability maps produced using Index Method and GIS were validated through field surveys and by comparison with historical accounts of disasters and their corresponding impacts on agricultural productivity. It was concluded that the most exposed barangays were those near bodies of water and having vast agricultural land cover. Though the physical and environmental attributes of an area are substantial in determining risk, the vulnerability of the subject area was shown to be influenced by its internal (exposure) and external (sensitivity and adaptive capacity) factors. Thus, knowing and acting on indicators that are within human influence is essential in minimizing the effects of inevitable and uncontrollable phenomena.