Household economic burden from seawater intrusion in coastal urban areas with climate change implications -

Abstract

Population growth and urban development are often associated with increased water shortages as demand exceeds supply. Coastal areas, where population centers tend to concentrate, are particularly susceptible to these shortages with many coastal communities overexploiting groundwater resources to meet the demand, causing seawater intrusion to vital coastal aquifers. Climate change impacts in the form of sea level rise, increased temperature, and decreased precipitation are expected to exacerbate an already difficult situation particularly in arid and semi-arid regions. In turn, the salinization of groundwater in urban centers will invariably be translated into a social economic burden manifested through the purchase of water, damage to household appliances, and treating brackish groundwater. In this study, a coastal pilot area experiencing chronic water shortages was considered to assess the direct and indirect household economic burden associated with water shortages and the use of brackish groundwater. For this purpose, socio-economic characteristic data collected through field surveys were coupled with measured salinity levels and empirical models to quantify the incurred societal burden in the form of purchase of water, reduction in the lifespan of household appliances, and the proliferation of building-level brackish water treatment systems. Groundwater samples highlighted the magnitude of saltwater intrusion, with total dissolved solids reaching up to 31,000 ppm. Economic burdens were found to increase as a function of salinity levels with a median expenditure on water reaching 5.1percent of a household’s income, a percentage significantly higher than worldwide average household expenditure on water. The study concludes with city adaptation measures towards minimizing future impacts associated with increased coastal salinization induced by an accelerated urbanization rate coupled with projected climate change impacts.