Predicting Cropland Decline in Coastal Bangladesh Using Recent Landsat Satellite Data.

The food sector of Bangladesh saw significant transformation from 1990 to 2025. Population growth intensified, urban areas expanded, climate pressures heightened, and competition for land escalated. Government data indicate increased agricultural production; nonetheless, food imports continued to escalate. This disparity prompts a fundamental inquiry regarding the extent of existing cropland and the sustainability of current production trends. This study utilizes satellite data to investigate the reduction of cropland in the coastal Khulna Division over the past thirty years and its implications for national food security amid increasing environmental stress. A multi-temporal farmland mapping methodology was developed utilizing Landsat 8/9 data. The model was enhanced using a region-specific NDVI threshold to rectify persistent inaccuracies identified in the GF-SAD30 dataset. Images from November to March were chosen to distinguish active cultivation from fallow areas and aquaculture ponds, enhancing the identification of seasonal cropping patterns. Cropland trends from 2014 to 2025 were reconstructed and extrapolated through trend-based forecasts to estimate future land loss assuming existing land-use patterns persist. The findings indicate a uniform and geographically focused reduction in agricultural land. Forecasts suggest a possible decline of 42 to 56 percent over the next decade if conversion trends remain constant. The most impacted locations correspond with settlement expansion routes, aquaculture development zones, and places vulnerable to salinity intrusion and waterlogging. The investigation clarifies the reasons for the perceived resilience in production figures. Intensified cropping and reduced fallow durations enhance yield per unit area and momentarily obscure the physical degradation of arable land, fostering a faceade of expansion amidst increasing reliance on imports. These data indicate a structural disjunction between the availability of cropland and the reported increases in food production. The findings underscores the necessity for enhanced cropland protection, land governance that aligns with climatic reality, and the regular implementation of satellite analysis in agricultural planning. In the absence of these measures, dependence on food imports would intensify, and national vulnerability to fluctuations in the global food market will escalate.

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