Mangrove damage based on canopy density derived on SPOT 6 at Ngurah Rai forest park, Bali

Abstract

The Indonesian government has launched a mangrove rehabilitation program of 600,000 ha in 2021-2024. This program needs information about mangrove forest damage obtained quickly and accurately. Remote sensing technology is a solution to the availability of the required speed of information. Mangrove damage information can be obtained from the canopy density derived from the vegetation index. This study aims to detect mangrove damage based on the density level derived from the vegetation index. The data used are SPOT 6 satellite imagery recorded in 2020 with the research location in Ngurah Rai forest park. The vegetation index used is Normalized Different Vegetation Index (NDVI), Green Normalized Different Vegetation Index (GNDVI), and Optimized Soil Adjusted Vegetation Index (OSAVI). Field data for validation were collected by the vertical photos that provide information on the percentage of canopy density. Furthermore, the density model was built using linear regression and validation using the coefficient of determination (R2). The results show that the vegetation index positively correlates with canopy density. NDVI and OSAVI have an identical R2 of 0.75, while GNDVI has an R2 of 0.70. Generally, the mangroves in Ngurah Rai forest park are dominated by mangroves in good condition and only 2.81% in some locations in damaged condition.