Mangrove cover change analysis of Sibuyan Island, Romblon, Philippines

Vicmar Jugado; Vida Carandang; Josephine Garcia; Dixon Gevaña

Vicmar F. Jugado Institute of Renewable Natural Resources, College of Forestry and Natural Resources, University of the Philippines Los Baños, College, Laguna, Philippines
Vida Q. Carandang Institute of Renewable Natural Resources, College of Forestry and Natural Resources, University of the Philippines Los Baños, College, Laguna, Philippines
Josephine E. Garcia Institute of Animal Science, College of Agriculture and Food Science, University of the Philippines Los Baños, College, Laguna, Philippines
Dixon T. Gevaña Department of Social Forestry and Forest Governance, College of Forestry and Natural Resources, University of the Philippines Los Baños, College, Laguna, Philippines

Keywords: climate change, geospatial analysis, mangrove vegetation density changes, Normalized Difference Vegetation Index

Abstract

Mangrove forests are one of Earth's most productive and adaptable ecosystems, offering nature-based climate change mitigation and adaptation solutions. However, these forest habitats are experiencing rapid loss, and studies supporting their conservation are still emerging. This study used a geospatial analysis approach to assess the cover change of a critical mangrove reserve: Sibuyan Island, Romblon, Philippines, between 2010 and 2020. Normalized Difference Vegetation Index (NDVI) analysis was performed using radiometrically corrected Landsat 7 and 8 scenes through ArcGIS to determine the island’s spatiotemporal changes in mangrove area by vegetation density (bare, sparse, and dense). The accuracy of NDVI images was computed using an error matrix, which showed high accuracy in the classification process. Results showed that over the 10 years, the mangrove area increased by 182.8 ha. The dense vegetation increased by 6.0% yr–1, while bare and sparse vegetation decreased annually by 26.7% and 10.1%, respectively. Rehabilitation programs and the strict implementation of mangrove protection and management policies are the likely drivers of change. Consequently, sustaining these efforts is vital to conserving Sibuyan mangrove forests and preserving its benefits to the global climate and the local community.