Environmental change detection through remote sensing technique: A study of Rohingya refugee camp area (Ukhia and Teknaf sub-district), Cox's Bazar, Bangladesh

Geographically Ukhia and Teknaf are two sub-districts of Cox's Bazar, Bangladesh, have conveyed a significant standing for the wildlife and the forest cover. However, the prominent phenomena go through a drastic change over the decades by the various anthropogenic activities i.e., massive Rohingya refugee camp settlements, deforestation, environmental degradation, wildlife losses etc. The objectives of this study are to detect and analyse the environmental change along with future prediction. The study has used Landsat 5 TM and Landsat 8 OLI TIRS imagery of 1990, 2000, 2010 and 2020. To analyse the change of environment NDVI, MLC and CA-ANN model were performed. Foremost land use and land cover (LULC) categories were recognized in this study area, viz. agricultural land, sandy land, settlements, vegetation, water bodies and refugee camp. The result revealed that the change of environment was more rapid and notable from 2010 to 2020 change period than 1990–2000, 2000–2010, and 1990–2020 periods. In this period, agricultural land, settlements, and refugee camp increased by 3335.61 ha (34%), 1198.45 ha (13%) and 2129.79 ha (582%), respectively; however, significant losses were observed for the vegetation 5181.00 ha (17%), water bodies 1039.47 ha (15%) and sandy land 445.32 ha (78%). This study also demonstrated that nearly 21,409.12 ha (37.46%) land cover of the entire study area has been transformed over three decades (1990–2020) and approximately 2495.63 ha (4%) land transformed only for the Rohingya refugee camp settlements. The simulated model result revealed that the vegetation cover would decrease about 2524.95 ha from the year 2020 and settlements of the area would increase about 977.04 ha in 2030. Finally, the outcomes of the study suggested a comprehensive environmental management plan of the region