Assessment of land use transition and crop intensification using geospatial technology in Bangladesh

Despite dealing with numerous challenges, the agricultural sector in Bangladesh is consistently growing every year because of the crop intensification efforts in many areas to ensure food security. However, the effect of intensive cropping on land use changes remains unclear due to the lack of systematic monitoring. This study assesses Land Use Land Cover (LULC) dynamics, particularly in Bhanga Upazila (a subdistrict), Bangladesh, using remote sensing and GIS technologies. Landsat 5 and 8 satellite imagery to understand the impact of agricultural intensification from 1988 to 2023. This study showed that agricultural land utilization was increased by more than five times (551.8%) and the built-up area was expanded by 155.6% during the study period. This substantial land conversion was expected due to the significant decrease of barren and waterbodies by 63.1% and 72.4% at the same time respectively. Despite the fact that Bhanga was a typical rural place where agriculture had only a 5% (1012 ha) share of its total land (20,309 ha) back in 1988, Bhanga experienced a notable surge in agricultural land utilization over the past three decades from 5.0% in 1988 to 32.5% by 2023, with a temporary dip to 2.4% post a devastating flood in 1999. The Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) analyses justify the increase of agricultural and built-up zones, contrasting significant decrease in waterbodies and barren areas as detected by RF (Random Forest) machine learning algorithm. These findings reveal that crop intensification initiatives convert waterbodies and barren lands into croplands. Government policies and supports such as various agriculture extension activities, availability of irrigation facilities, adaptation of technologies, and improved regional connectivity likely contributed to this positive transformation. This study offers crucial insights for policymakers to take region-specific customized agricultural strategies to ensure food security and sustainability. •Showcasing the dynamic nature of agricultural landscapes over time.•Utilizing NDVI and NDWI to understand the land use dynamics.•Witnessing significant agricultural land utilization: 5.0% (1988) to 32.5% (2023).•Government policy and numerous extension efforts propel agricultural land growth.•Proving crucial insights to guide policymakers for future sustainable land management.