Application of Satellite Remote Sensing to Identify Climatic and Anthropogenic Changes Related to Water and Health Conditions in Emerging Megacities

By 2050, more than 70% of the world’s population is expected to be living in a city. In many of the urbanizing regions in Asia and Africa, most new development is taking place without adequate urban or regional planning, and a majority population is crowded into densely populated unplanned settlements, also known as slums. During the same period, precipitation and temperature patterns are likely to see significant changes in many of these regions while coastal megacities will have to accommodate sea-level rise in their ecosystems. The rapid increase in population is usually observed in fringes of the urban sprawl without adequate water or sanitation facilities or access to other municipal amenities (such as utilities, healthcare, and education). Collectively, these issues make the ever increasing slum dwellers in emerging megacities significantly vulnerable to a combination of climatic and anthropogenic threats. However, how the growth of unplanned urban and peri-urban sprawl and simultaneous change in climatic patterns have impacted public health in the emerging megacities remain largely unexplored due to lack of readily available and usable data.

We employ a number of Remote Sensing products (GRACE, LANDSAT, MODIS) to bridge above knowledge gaps and to identify relevant hydrologic and anthropogenic changes in emerging megacities that are most vulnerable due to the climate-water-health nexus. We explore one of the largest and the fastest growing megacities in the world – Dhaka, Bangladesh – on identifying and investigating the changes in the water environment and growth of slum areas, and impact on water services and health outcomes. The hydroclimatology of South Asia is highly seasonal and the asymmetric availability of water affects vast areas of Bangladesh differently in space and time, exposing the population of Dhaka region to both droughts and floods and periodic spring-fall outbreaks of diarrheal diseases, such as cholera and rotavirus. This research focuses on stretching this understanding to water and health implications in this growing megacity and adjoining slum areas, and how satellite remote sensing data products and derived knowledge can inform urban planning, water management, and public health sectors to adapt to these climatic and anthropogenic changes for the benefit of societies.