world water use

661 Words2 Pages

Water, the liquid of life, like air and soil has no substitute. Life, as we know it, would not exist without water. The geosphere, the atmosphere and the biosphere are all linked to, and by, water. Water interacts with solar energy to determine climate and it transforms and transports the physical and chemical substances necessary for all life on earth. While 70 % of the planet’s surface is covered by water, most of it is saltwater; freshwater is limited and is not always in the right place, at the right time, or of the right quality. Water, on Earth, exists in several states: water vapor and clouds in the sky, seawater in the oceans, icebergs in the polar oceans, glaciers in the mountains, fresh water lakes, rivers, and fresh and saline water in aquifers. There are significant continental and country differences in the availability of freshwater.
Over the last 25 years, these differences and the importance of water has grown to occupy national and international agendas. Many international organizations, such as the United Nations, the World Bank, the World Health Organization, the World Meteorological Association, and the Stockholm International Water Institute, hold conferences related to water issues. Awareness among scientists, political leaders and citizens of the connections between climate change, the hydrologic cycle, food production, environmental services, infrastructure needs, and sustainable water resource management increases every year. The message highlighted by all these efforts is that water is an increasingly scarce resource and that it is important to recognize and accept that there is a finite supply of water. Competition among agriculture, industry, and cities for limited water supplies is already constraini...

... middle of paper ...

...). Although floods and droughts have always plagued mankind and agriculture, they serve to heighten awareness on water issues and the need to wisely use and manage water resources.
As a prelude to sustainable water management for agriculture and food systems, this chapter briefly outlines water supply and use factors and challenges for the future. It begins by briefly providing an overview on the physical and chemical uniqueness of water before discussing water location, availability and uses. A section on “virtual water” provides information on the amount of water embedded in food, fiber, and products. Impacts of drought and climate change on water availability are outlined. Before the conclusion, issues with transboundary surface and groundwater resources sharing and management are highlighted. These issues will become increasingly complex as the climate changes.

Open Document