Adaptation pathways to cope with salinization in south-west coastal region of Bangladesh

Salinization in coastal regions of Bangladesh challenges sustainable development of different sectors like agriculture, forestry, fisheries, livestock, and health. Particularly its southwest region largely faces increased salinity risks because of its geographical location and environmental settings. This study analyzes the causes of salinity increase, their cascading impacts on different coastal systems, and their livelihood implications, and assesses potential coping measures through innovative adaptation pathways for the most affected coastal systems. These pathways integrate bottom-up and top-down perceptions in adaptation planning through a driver-pressure-state-impact-response framework, multicriteria analysis, and adaptation turning point approaches. We surveyed 200 households and interviewed 20 key informants. We observed that household-level respondents' perceptions are more closely related to socioeconomic aspects than to the biophysical environmental aspects and focus on issue-based action. However, the key informants focus more on the biophysical changes and the large-scale measures. The developed framework shows that salinity increase is an interconnected process of climatic-social-ecological-economic systems in the coastal environment. It also shows that responses already taken, i.e., polders and shrimp farming, to cope with salinization have later become pressures, i.e., riverbed siltation, waterlogging, and intensive salinization, on the systems. In total, we identified six interconnected causes of salinity increase and 24 potential measures to address them. Also we distinguished three coastal systems, i.e., crop-agriculture, drinking water sources, and the Sundarbans mangrove, most affected by salinity increase. Finally we proposed 16 adaptation pathways for these coastal systems based on the multicriteria analysis and adaptation turning points of the potential measures.