3.6 Water resources
3.6.1 - Describe the Earth’s water budget.
About 70% of the Earth’s surface is covered by water. Only 3% of all water is fresh (drinkable) and the rest 97% is salty water in the oceans. As the percentages show, freshwater is quite short in supply. About 69% of this freshwater is in the polar ice caps and glaciers and about 30% in groundwater. Water quantity in lakes, rivers and swamps is only about 0.3% of total available. Even the whole atmosphere holds less than 0.001% of total water volume.
Turnover time is the time it takes for a molecule of water to enter and leave part of the system. For example from the ice cap in oceans, to the groundwater or soil. |
3.6.2 - Describe and evaluate the sustainability of freshwater resource usage with reference to a case study.
Irrigation, industrialization, and population increase all make demands on the supplies of fresh water. Global warming may disrupt rainfall patterns and water supplies. The hydrological cycle gives humans fresh water but we are taking up so much water from the underground aquifers that there is no time for it to replenish.
The demand of water has increased in both MEDCs and LEDCs, as populations are increasing as well as agriculture changing and expanding industry. MEDCs need more water as they wash more often, water their gardens, and wash their cars. This means that the increasing use of water is making the demands higher. Water is not an infinite resource and has to be controlled more carefully, and new water resources need to be found.
Water can be managed if individuals and communities make changes and this should be supported by the government. Water should not be over used or wasted so that it is insured it can be enough for everyone.This can be reached by:
As populations grow, greater demands are made on water resources. Water resources are now becoming a limiting factor in many societies, and the availability of water for drinking, industry and agriculture need to be considered. Many societies now are dependent on groundwater which is non-renewable. As societies develop, water needs to be increased. The increased demand for water can lead to inequity of use and political consequences. When water supplies fail, populations will be forced to take dramatic steps, such as mass migration. Water shortages may also lead to civil unrest and wars.
The demand of water has increased in both MEDCs and LEDCs, as populations are increasing as well as agriculture changing and expanding industry. MEDCs need more water as they wash more often, water their gardens, and wash their cars. This means that the increasing use of water is making the demands higher. Water is not an infinite resource and has to be controlled more carefully, and new water resources need to be found.
Water can be managed if individuals and communities make changes and this should be supported by the government. Water should not be over used or wasted so that it is insured it can be enough for everyone.This can be reached by:
- fitting new homes with more water-efficient appliances (dishwashers and toilets)
- expand metering to encourage households to use water more efficiently
- in some rural areas drought resistant crops should be planted to reduce the need for irrigation
- organic fertilizers cause less pollution and bio-control measures can be used to reduce crop pests
As populations grow, greater demands are made on water resources. Water resources are now becoming a limiting factor in many societies, and the availability of water for drinking, industry and agriculture need to be considered. Many societies now are dependent on groundwater which is non-renewable. As societies develop, water needs to be increased. The increased demand for water can lead to inequity of use and political consequences. When water supplies fail, populations will be forced to take dramatic steps, such as mass migration. Water shortages may also lead to civil unrest and wars.
Water shortages in the Middle East:
Water shortages in the Middle Eastern countries are very common and as time passes their water supply is decreasing. Even though the region only inhabits 5% of the world’s population, it only has 0.5% of the world’s freshwater. It is predicted that the water supply will decrease from 3430 cubic meters per year to a 667 cubic meters by 2025. This is causing countries such as Israel who is suffering from a major drought to stop pumping from their major pumps of fresh water. Many factors have led to the demand of more water and the droughts have made this worse. Despite the shortages Israel is still sharing their supply with neighbouring country Jordan. At the moment, Israel is building plants that will supply a third of the countries water demand and a few more plants are also going to be completed in 2013 which could double this amount. Future water shortages could lead to conflicts between the bordering countries. |