Introduction :
- water always been a natural resource
- 80 countries now facing water shortage , 2 billion people lack access to clean water.
- global demand for fresh water will vastly outstrip reliable supply in many parts of world.
- 97.5% of water is sea water , left 2.5 % of “ fresh water “ but inside include glacier , ice packs , soil moisture , atmosphere , groundwater .
Factors driving to this situations :
1. Demographic pressure population growth rate surged up . expand world’s population from 7 billion to almost 8 billion by 2025 . affect the developing countries especially Africa . expanding urban centres , demand for fresh water will also increase for personal consumption , sanitation , industry and hydroelectric usage.
Approximately 1,700 m3 of water exists for every person on the planet, an alarming low number. According to the Water Stress Index, a region with less than 1,700 m3 per capita is considered “water stressed”.
2. Water Pollution
Water pollution is reaching epic proportions.
In the U.S. 40% of rivers and lakes are considered too polluted to support normal activities.
In China 80% of the rivers are so polluted that fish cannot survive in them. In Japan 30% of groundwater has been contaminated by industrial pollution. The Ganges River, which supports around 500 million people, is considered one of the most polluted rivers in the world.
It is a serious problem especially in the developing countries .
According to United Nations Environmental Program (UNEP), “in developing countries, rivers downstream from major cities are little cleaner than open sewers”.
1.2 billion people are being affected by polluted water, and dirty water caused 15 million child deaths every year.
Most of us supported by subterranean water reserves called groundwater. scientists aware the problems of contamination groundwater.
Aquifers move very slowly, so once they are polluted it takes decades or centuries for