Modeling land use and thermal change along Dhaka’s MRT line 6 using remote sensing and CA-ANN

Rapid metro-driven urban growth in major metropolitan regions has profound implications for land use change and urban thermal regimes. This study investigates the spatiotemporal evolution of land use/ land cover (LULC) and land surface temperature (LST) along the MRT Line 6 corridor in Dhaka, Bangladesh, within 0–600 m buffer zones using a multi-temporal geospatial framework. LULC and LST were extracted from Landsat and sentinel imagery for the years 2015, 2020 and 2025, while future land use pattern for 2030 were simulated using a Cellular Automata-Artificial Neural Network (CA-ANN) approach. Model performance was assessed using Chi-square (χ2) goodness-of-fit statistics to evaluate the agreement between observed and simulated results. The findings reveal pronounced metro-induced urban restructuring, with built-up areas increasing from approximately 15.88 km2 in 2015 to 16.36 km2 in 2030, largely driven by the conversion of green spaces, which declined from 5.84 km2 to 4.51 km2, alongside reductions in barren land. Mean LST demonstrated a clear multiphase pattern, rising by approximately 8–9 °C during the construction phase (2020) relative to 2015, followed by a decline of about 10–11 °C in 2025. This decrease reflects short-term stabilization rather than persistent cooling. Projections for 2030 indicate an expansion of moderate to high LST zones in response to continued urban growth, suggesting a potential resurgence of thermal stress. These results emphasize that although metro infrastructure improves urban connectivity, it may also contribute to long term thermal challenges if ecological factors are not adequately incorporated into planning frameworks. Accordingly, the integration of climate-resilient measure including the conservation of green infrastructure, implementation of climate-sensitive zoning and adoption of heat mitigating urban design strategies is essential to support sustainable metro corridor development in Dhaka and comparable rapidly urbanizing South Asian megacities.