The fresh water constitute only 3% of the total water on earth out of which underground water constitute 29 and <1% is in the form of lakes and rivers on the earth surface. Considering the rapidly increasing human population and demand for diverse food items crop production must increase substantially. At the same time arable land and good quality irrigation water resources are being depleted at faster rate particularly in the arid, semi-arid and tropical regions. Over the years the salinization of soil and water has steadily increased due to various causes and the increase in food production has essentially depends on this degrading resources. Since the balance between water demand and water availability has reached critical level in many regions of the world a sustainable approach to water resources and salinity management has become imperative. This chapter highlights global water resources, its demand and supply, salinity and its causes, effect of climate change and its management for sustainable use.
Part of the book: Desalination