Spatial-temporal dynamics of mangrove extent in Quang Ninh Province over 33 years (1987–2020): Implications toward mangrove management in Vietnam

Abstract

Remote sensing technology offers a huge potential to continuously monitor the changes in mangrove forests. Mangrove deforestation has resulted in a loss of coastal ecosystem services and associated economic benefits. Quang Ninh is the third largest mangrove area in Vietnam, but has experienced mangrove deforestation and degradation since 1987. The study used historical Landsat-5/8 and Sentinel-2 data to quantify spatial–temporal dynamics of mangrove extent from 1987 to 2020. The CMRI was used to construct LULC and post-classification comparison was used for change detection analysis over the study period. The overall accuracies of 94.8%, 94.1% 92.4%, and 89.9% were recorded in 2020 (Kappa = 0.917), 2017 (Kappa = 0.906), 2010 (Kappa = 0.872), and 2000 (Kappa = 0.832), respectively. The dynamics of mangrove forests in Quang Ninh were influenced by mangrove deforestation and afforestation. The extent of mangrove forests decreased by 2168.3 ha from 1987 to 2020. Mangrove deforestation was mainly caused by unplanned aquaculture, urban development, and other land uses. However, the root of mangrove deforestation is found due to inappropriate regulations and institutional schemes related to mangrove management. The study suggests that community-based mangrove management model and blue carbon approach are suggested in Quang Ninh and Vietnam.