Land Use Land Cover Change, Carbon Storage Dynamics, and Future Urban Growth Simulation in Dhaka Metropolitan Area (1994-2044) Using CA-ANN and InVEST Models

Rapid urbanization has dramatically transformed land use land cover (LULC) patterns and ecosystem services in megacities of the Global South, with major implications for carbon storage and climate regulation. This study investigates LULC dynamics, associated carbon storage changes, and future urban growth in the Dhaka Metropolitan Area from 1994 to 2044. Multi-temporal Landsat imagery was used to classify six LULC categories for 1994, 2004, 2014, 2019, and 2024. Carbon storage was quantified using the InVEST model by integrating LULC maps with literature-based carbon density values representing four carbon pools. Future LULC scenarios for 2034 and 2044 were simulated using a Cellular Automata–Artificial Neural Network (CA-ANN) model within the MOLUSCE framework, incorporating six biophysical and infrastructural driving factors. Model validation produced an overall accuracy of 70.13% with satisfactory kappa indices. Results reveal that built-up expansion occurred mainly at the expense of vegetation and water bodies, causing nearly a 40% decline in total carbon storage between 1994 and 2024, with water bodies contributing the largest share of carbon loss. Process-based analysis identified dominant transformation clusters driven by urban reclamation and hydrological loss, alongside vegetation clearance and land degradation. Future projections indicate continued urban growth and further carbon depletion by 2044. These findings highlight the urgent need to conserve wetlands and urban green spaces and to integrate carbon-sensitive strategies into sustainable urban planning.