Assessing urban growth dynamics of major Southeast Asian cities using night-time light data

This study analysed urban growth patterns for 15 Southeast Asian cities using remotely sensed night-time light data from1992 to 2012. We extracted three urban categories (countryside, peri-urban, and core-urban) for each city using objectively derived thresholds from the brightness gradient (BG) approach. The peri-urban and coreurban combined categories were generally found to increase over time for all cities whereas countryside urban category decreased implying strong spatial and temporal trends in urbanization. These trends were also found to be sensitive to geographic characteristics of cities. The study showed that the BG approach can be successfully applied to extract and study growth dynamics of different urban categories for Southeast Asian cities having range of demographic and socioeconomic conditions. The BG derived urban categories compared favourably with Landsat derived impervious areas, where the former was found to envelope the high percentage impervious region derived from the latter. The BG-derived urban areas are lastly compared against the population data to explore linkages with population growth.