Spatiotemporal Correlation Between Biophysical Parameters and Land Surface Dynamics in an Archaeological Region of Bangladesh

The Mainamati-Lalmai hilly region in southeastern Bangladesh is renowned for its enormous historical, cultural, and environmental values, including 15 well-preserved archaeological sites and ancient Buddhist monasteries from the 7th century. However, urbanization has profoundly transformed the landscape of this area over the last two decades. This study utilizes the Landsat 5 TM and 8 OLI imagery to analyze land use and land cover (LULC) changes, land surface temperature(LST), biophysical parameters (NDVI and NDBI) from 2004 to 2025, using geospatial software and Google Earth Engine platform. The land use of this research area has been classified into four categories: crop land, built-up land, forest cover, and waterbodies. The results show that built-up land has grown significantly while other land classes, mostly forest cover, have decreased more. The built-up land has expanded from 212.35 ha in 2004 to 1481.37 ha in 2025 at the cost of other land classes, in particular forest cover, that was overall reduced by 36.9% over the last 21 years. The LST in this area has risen by more than 6° C, with temperatures increasing across approximately 75% of the area since 2004 and the NDVI values have also seen a declining trend here. LST and NDVI show a strong negative correlation while LST and NDBI exhibit a strong positive correlation. The findings quickly highlight the rapid unplanned urbanization in this ecologically sensitive area, which is likely to have a massive impact on the archaeological sites as well. This study recommends taking urgent necessary steps for sustainable land management and urban planning strategies with specific laws to preserve the archaeological sites and the environment.