Reports of drought have increased world-wide, but beyond the obvious, a lack of rain, few people are aware of how different factors cause water shortages. However, local rainfall is rarely the real reason behind a sudden lack of water available for drinking or farming. The consistent availability of water is the result of a complex web of interactions.
Where it All Starts
The amount of water on the planet remains a constant. Where it is located, and its condition, however, is variable. At any given moment water can exist as a liquid, gas or solid. For example, the polar ice caps have long held great quantities of solid water. As climate change occurs an increasing amount of that fresh water is being released into the oceans and atmosphere.
Water that is used for agriculture and drinking most often comes from rivers and aquifers. As the population drawing upon those sources has grown, so has the demand. Additionally, centuries of poor water management has lead to the pollution of many formerly usable sources of water. These, and other issues, are some of the causes of water shortages which are coming to light today.
Who is Affected?
According to Nature(2010), a well respected source, 80% of the world’s current population live in areas where water availability is compromised. Intensive agricultural use and dense population centers overtax existing water sources, leading to regular shortages.
Periods of drought, which occur regularly, are only a small factor, according to scientists; increases in population have a greater effect. Any inhabitants which lack the ability to transport sufficient water to their location are likely to suffer from shortages in the future.
Causes of Water Shortages Around the World
With climate change results in rises in temperature everywhere, rainfall may actually increase rather than decrease. In a counter intuitive fashion, higher temperatures cause more rain because they increase evaporation, but the water doesn’t stay where it is needed; yet another of the causes of water shortages in cetain areas. Furthermore, with even modest increases in seasonal temps, snowfall is decreasing, and it is snow, more than rain, that fills reservoirs and replenishes ground water.
National Geographic News states that changes in snowfall causes water shortages as well. With less snow and earlier spring runoff less water is being caught by dams. More of the runoff is ‘wasted’ and is lost. The snow that falls in the mountains is a natural reservoir which isn’t being replenished properly any more. With nearly a sixth of the world’s population dependent upon such snow based water sources, things look grim indeed.
Rethinking Water Use
Perhaps the biggest problem with the continued exploitation of fresh water sources is the fact that as they are used the water isn’t being replaced with new, fresh water. Aquifers are being polluted by chemical run off and salinity is increasing underground.
The World Water Council, which runs annual meetings on the causes of water shortages expresses concern that if countries don’t start to address water issues across borders conflicts may erupt. Changes in food production processes is one of the many suggestions that have been offered to help decrease demand on limited water resources.
A Water Monitoring Alliance is in developmental stages. It is hoped that better monitoring, reduced waste and greater cooperation may be the key to ensuring that all have access to the water they need. While water shortages are currently occurring on a local basis, rather than globally, it is only a matter of time before what seems like a distant problem comes home to roost everywhere.
http://news.nationalgeographic.com/news/2005/11/1121_051121_warming_water.html
http://www.worldwatercouncil.org/index.php?id=25