Monitoring of land use and land cover changes by using remote sensing and GIS techniques at human-induced mangrove forests areas in Bangladesh

Human-induced wetlands are more exposed to threats around the world. For conserving and protecting wetland resources, such as mangrove forests, it is significant to monitor the wetlands and their associated land features and land cover use. The land use and land cover (LULC) changes with remote sensing have been used with different aspects to evaluate the wetland's change dynamics in many areas. This study used four satellite images of Landsat 5 and 8 for LULC mapping of mangrove wetlands and their adjacent areas to evaluate the change dynamics for 1990, 2000, 2010, and 2020. During the period 1990 to 2020, significant changes in land features have been observed. The LULC analysis revealed a remarkable increase in aquaculture and a significant decrease in agriculture. The NDVI (−0.08 to 0.35) and NDWI (−0.10 to 0.32) indices analysis also visibly confirmed changes in land features. The aquaculture area was increased by 5686 ha (∼230%), whereas the agricultural area decreased by 6682 ha (∼66%) in 2020 compared to 1990. The analysis also found a decrease of 1881 ha (∼14%) of the forest area for the same period. A decrease in agricultural lands and an increase in aquaculture areas indicate that inhabitants in the area change their profession over the period. This transformation has negatively impacted human-induced activities in the ecosystem and biodiversity of mangrove forests. The biodiversity welfare of natural wetlands, such as mangrove forests, is gradually reduced because of human interventions in the study area. Therefore, appropriate measures need to be imposed to improve the condition of mangrove forests and protect forest biodiversity.