Monitoring assessment of mangrove forest cover changes in Puerto Princesa Bay, Palawan between 1999 and 2020

Abstract

Mangrove forests provide vital benefits to coastal communities. Despite its value, the decline in mangrove forests in the Philippines has been documented, primarily due to human activities. Long-term monitoring of the spatial distribution of local mangrove forests is critical for understanding the dynamics of mangrove forests. This study investigated the extent of Puerto Princesa's mangrove forests, which are among the most diversified in the country. Landsat composite were classified based on spectral signatures using a Random Forest machine learning classification script in Google Earth Engine. From 965 hectares in 1999 to 1094 hectares in 2020, mangrove forest area in Puerto Princesa Bay has grown by approximately 13%. Loss and gain maps show that most mangrove losses are located where there is a substantial increase in built-up areas, indicating human activity's influence on mangrove decline. Mangrove expansion is observed landward and seaward. Mangrove forests' health and canopy density improved based on their NDVI values. This can be an indication of the successful policies and restoration initiatives that have been put into place to conserve the mangroves in Puerto Princesa Bay.