Evaluation of the Can Gio Vegetation Index changes using the Sentinel-2 Datasets from 2015 to 2023

Abstract

Can Gio Mangrove Biosphere Reserve provide many ecosystem services, such as provisioning, regulating, cultural, and supporting services for the urban areas as well as wildlife of suburban areas in Ho Chi Minh City and the nearby ecosystems. Therefore, it is important to monitor and evaluate the change of mangrove forest cover in the long term. In this study, the Normalized Difference Vegetation Index -NDVI at 10 m resolution from 2015 to 2023 of Can Gio was obtained from the Copernicus Sentinel-2 database using Google Earth Engine -GEE. Subsequently, NDVIs statistic were computed by R to assess the slope of NDVI change with p-value significance in Can Gio. The results indicated that NDVI values typically range from -0.4 to +0.8 and vary annually. It is evident that NDVIs values from 2015 to 2020 are marginally higher than those recorded between 2021 and 2023. The degradation in average NDVI from 2015 to 2023 was rationally deducible either from the downsizing of mangrove forest areas or the degradation of the mangrove forest. However, the annual NDVI statistic revealed there were areas with an acceleration of NDVI in comparison with the destruction of NDVI areas from 2015 to 2023. Linear regression effectively models continuous processes like deposition or erosion. However, to evaluate other factors such as discrete human-made or sporadic impacts, alternative statistical models should be considered.