Physical Vulnerability Assessment Of The Coastal Environment Of Bunaken Island, Indonesia

Abstract

The use of Coastal Vulnerability Index (CVI) is a technique applied to estimate and classify vulnerability of coastal areas. This approach aids in informing the level of vulnerability or resilience of an island based on its prevalent biophysical, environmental and socio-economic conditions. This study assessed the physical vulnerability of Bunaken Island and of eight (8) of its popular sites classified under different management zones. Bunaken Island is a protected marine environment located in Manado City, South Sulawesi, Indonesia. The CVI vulnerability matrix used for the assessment considered seven (7) physical parameters - beach width, dune width, coastal slope, distance of vegetation behind the back beach, distance of built structures behind the back beach, sea defenses, and shallow water habitat. The average CVI per parameter and cumulative physical coastal vulnerability index (PCVI) were computed, ranked, and evaluated to develop the vulnerability profile of each site and determine relative vulnerabilities based on management zone and specified physical parameters. Average PCVI rating of Bunaken Island was 17 suggesting that the island is moderately vulnerable. However, four out of the eight sites were highly vulnerable with Alung Banoa C and Raymonds being the most at risk. The findings in this study when integrated with an expanded CVI assessment that covered other socio-economic and environmental aspects m ay prove valuable in planning management strategies to protect areas at risk and improve resiliency of this coastal environment.