Total water on Earth is over 1 387 million km 3 , but of which only 2,5% is fresh water land (pie chart). Composition of freshwater in the world given the cylindrical diagram. Really fit for a small portion of fresh water rivers and lakes. A significant portion of the amounts of fresh water located in remote areas and little explored.
global distribution of freshwater resources is very uneven and depends on geographical location and natural conditions of the territory.
world's reserves of fresh water can not be increased, while water consumption is growing, moreover, the water becomes dirty and unfit for use. Because the planet is already the problem of scarcity of fresh water. Water deficit so far has mostly a regional character. He is particularly felt in areas with arid climates, where the full resources of river runoff per capita less than 5 thousand 3 per year. Agriculture in these areas is possible on irrigated lands.
ways to tackle water shortages are a few:
- reducing water consumption in agriculture;
-implementation in industry and shallow waterless technology of closed water (waste water reuse);
- desalination of sea water, use water icebergs;
- construction of reservoirs to regulate river flow.
in the world built over 60 000 reservoirs. The largest ones are shown on the map. In Ukraine on the Dnieper reservoirs built a cascade that accompanied the construction of hydropower plants. However, the reservoir and create a significant problem - changing river beds, flood the fertile coastal land, climate change etc..