Integrating cultural, economic, and environmental requirements for fresh water
Fresh waters are central to societal and environmental vitality. The landscape is shaped by the quantity, quality, form, and timing of water movement, and water shapes society by affecting patterns of human demography, culture, economics, and the host of other characteristics that support healthy, secure, and vibrant populations. Changes in the distribution, abundance, and quality of water resources and freshwater ecosystems represent a strategic threat to the quality of human life, the environmental sustainability of the biosphere, and the vitality of human cultures. Nearly every country in the world experiences regular short-term water shortages, and \textgreater80 countries experience more serious water shortages. The need for improved efficiencies in water use and quality has never been more urgent with agriculture now using ∼87\% of the world’s fresh water and ∼90\% of all illnesses in developing countries resulting from waterborne parasites and pathogens. Often hidden in such statistics are the needs of the environment for adequate water to maintain vibrant ecosystems and thus the services and products they provide. Understanding the abilities and limits of freshwater ecosystems to respond to human-generated pressures is a central issue for cultures and a challenge for science.