Global water supplies are linked to three main physical factors: rivers, systems and geology.
The hydrologic cycle begins with the evaporation of water from the surface of the ocean. As warm air is lifted, it cools and water vapour condenses to form clouds. Moisture is transported around the globe until it returns to the surface as precipitation. Once the water reaches the ground, one of two processes may occur:
1) some of the water may evaporate back into the atmosphere or
2) the water may penetrate the surface and become groundwater. Groundwater either seeps its way to into the oceans, rivers, and streams, or is released back into the ...view middle of the document...
Only 1% is accessible and held in lakes, ecosystems, the atmosphere and rivers.
Like with all other resources, as global population grows, the demand for water increases. Water rich countries (Canada, Brazil etc.) will not be at serious risk because of this but others like African countries, it may be life threatening. Very many African and Middle Eastern countries already suffer from lack of clean water and in the years to come there will be less water per person. Even rich countries such as USA, China and India are set to suffer water stress as there are insufficient renewable water supplies.
A third of the world’s population are already short of water ad this figure is set to rise by over 10%.
Rising Demand: There is rising demand for water in the agriculture, industry and domestic use.
Agriculture: As the world population increases, there is more of a struggle to meet demand for food. 69% of the world’s water is used on agriculture p/a . Some forms of agriculture are not very efficient and can be wasteful.