Asia, located primarily in the eastern and northern hemispheres, is the world’s largest and most populous continent, Population of Asia 2011 is 3,879,000,000 (3.8 billion). It covers 8.6% of the Earth’s total surface area (or 29.9% of its land area) and with approximately 4 billion people, it hosts 60% of the world’s current human population, But only about 36 percent of the renewable fresh water. So, even on a continental scale, it is clear that water is a serious constraint in Asia. China, India and Pakistan are three of the four top irrigators in the world, suffering with serious water problems. Pakistan has in most areas of agriculture a monsoon climate, and there might be abundant rainfall during the wet season and then a very long dry season where crop production depends very heavily on irrigation water. Groundwater is a very important source of irrigation for farmers. Ground water is being over-pumped extensively in order to meet current demands for food production but if ou...