Satellite Remote Sensing Based Assessment of Environmental Sustainability of Water, Vibrios and Human Health

Human well-being is one of the key long-term indicators of a sustainable environment. John Snow, a prominent 19th century physician, provided insights on role of drinking contaminated water and cholera outbreaks. Extrapolation of Snow's discovery on locating the source of cholera (in local wells) leads to the tenets of traditional doctrines of environmental sustainability of water where source capacities (such as physical conditions of water) are convolutedly linked to sink capacities (bacteria growth in water) of a system, a balance that must be maintained to sustain human life supporting mechanisms. With a changing climate, stresses on water availability in regions where population vulnerability interacts with hydroclimatic extremes is increasing, leading to question on how environmental sustainability of water will affect human wellness. A dynamic equilibrium exist between large scale geophysical (such as sea surface temperature-SST; precipitation, evaporative fluxes) and local scale water-ecological processes (salinity, plankton, organic matter) in water resources (ponds, rivers, lakes). The ecological processes aid in growth and proliferation of water based pathogens (such as cholera, rotavirus, Shigella and other vibrios). Societal determinants, such as access to safe drinking water and sanitation facilities, defines interaction of population with water for daily activities. The feedback loop, between geophysical and water-ecological processes is fundamental to ensure a sustainable environment for human well-being. As an example, an increase in sea surface temperature (geophysical process) may lead to decrease in plankton growth (water-ecological process) in tropical coastal regions. This may have a reinforcing feedback loop where loss of plankton may result in loss of carbon absorption (or sink source) leading to increased greenhouse gases further limiting atmospheric conditions to form local storm systems. Additionally, an increase in SST in may trigger migration of plankton to new regions leading to disturbances in precipitation patterns and emergence of water-related diseases at new geographical locations. Geophysical processes affect societal determinants when extreme events such as flooding that limits access to water and sanitation facilities to population. Over the last several decades, significant progress has been made in understanding etiology of disease outbreaks from ecological and microbiological perspectives. Data from satellites is perhaps the only viable way to develop quantitative linkages between microbiology and climatic processes. This study will assess role of geophysical processes on water availability, determine suitability of ecological and environmental niches of vibrios. Using cholera and Shigella as example, results on new and emerging habitats of pathogens under changing climate will be presented.