Quantification of landuse changes driven by the dynamics of the Jamuna River, a giant tropical river of Bangladesh

Abstract

Changes in river bank location have wide consequences on floodplain communities and the sustainability of floodplain ecosystems. Although river dynamics are monitored globally and locally, understanding the impact of riverine dynamics on land use change remains a challenge. Bangladesh, part of the Bengal Delta, is mostly made up of alluvial deposits and is crisscrossed by so many rivers. Jamuna is one of the prominent rivers in this region. This study presents a consistent evaluation of the dynamics of the Jamuna river and ensuing changes in land use over 48 years (1972–2020) depending on satellite observations and geospatial analysis. Changes in the presence of water were used to estimate the advance/retreat of the banks and loss/gain of land along 257 perpendicular transects along the common pattern of the centerlines of the river. We found that the overall loss of agricultural land was about 535.01 km2, sevenfold of the gained agricultural land. Other land use losses were bare lands 136.73 km2, waterbodies 80.37 km2, settlement 67.28 km2 and vegetation 132.79 km2 against 48.47 km2, 3.52 km2, 23.76 km2 and 6.14 km2 land use gains respectively. Agricultural land loss impacts the livelihood of the floodplain dwellers and settlement loss causes internal migration. This pattern of land use change driven by the river dynamics has created newer environmental challenges and additionally, climate change may intricate the situation in the future. The findings of this study throw insight into the fact and may aid in sustainable river training measures and floodplain management.