Hazards induced by groundwater recharge under rapid urbanization

Abstract

Abstract Urban population growth across most of Latin America and Asia is relentless. Rapid urbanization has profound impacts on the hydrological cycle, including major changes in groundwater recharge. Existing infiltration mechanisms are radically modified, and new ones introduced, with evidence of an overall increase in recharge rates. There is also widespread diffuse pollution of groundwater by nitrogen compounds (normally nitrate, but sometimes ammonium), salinity (especially sodium chloride) and dissolved organic carbon. Groundwater contamination by petroleum and chlorinated hydrocarbons, related synthetic organic compounds, and, on a more localized basis, pathogenic bacteria and viruses, is also encountered. An analysis of the processes involved is made through citing detailed case histories.