How will Dhaka grow spatially in future?-Modelling its urban growth with a near-future planning scenario perspective

Abstract

Being the primate city of Bangladesh, higher population growth and inward migration from rural areas is making Dhaka to experience an unprecedented level of urbanisation. This has brought two-fold implications-pushing it high up the mega-city size ladder while also posing the planners and city managers with more complex spatial and socio-economic challenges to deal with the rapidly expanding urban footprint. Updating the knowledge and evidence-base of Dhaka's urban growth dynamics becomes increasingly crucial for better functioning of its strategic urban planning and management. Therefore, this research seeks to broaden our knowledge of understanding spatial urban growth patterns and processes of Dhaka over the period of 1988–2005. Hybrid spatial modelling frameworks, incorporating statistical models (in the form of weight-of-evidence approach) along with cellular automata functions, therefore, have been used to comprehend the dynamism of rapid urban growth from 1988 to 2005. As expected, the local version of the transition probabilities (where Dhaka was divided into 18 Spatial Planning Zones), produced improved results compared to the global version (i.e. the whole of the Dhaka metropolitan area). The modelling framework has further been tested as a planner's ‘what-if’ simulation box to generate near-future scenario using future policy dataset. It appears to have sufficient experimental potential to implement more extensive spatio–temporal land-use modelling process even in sparse data environment such as Dhaka.