Water is a basic production resource for agriculture. Competition for scarce water resources has been recognized as a potential source of international conflict. In the case of the Ferghana Valley, despite the very local character of the conflicts, the presence of international borders/or the implication of communities belonging to another ethnic group has loaded the conflict with a transborder and/or ethnic dimension. Earlier studies have shown ...

Mountain snow cover typically develops in the autumn and grows to a maximum depth in early spring. As day length and sun angles increase, so do air temperatures, causing snow cover to warm and begin to melt. Snow cover balances the availability of water in mountain environments. Where winter precipitation falls as rain, surface runoff occurs almost immediately. In contrast, snow stores water during the winter and then melts in the spring and ear...

Current patterns of human use of water are unsustainable. From 5% to possibly 25% of global freshwater use exceeds longterm accessible supplies and is met through engineered water transfers or the overdraft of groundwater supplies (low to medium certainty).

The imbalance in long-term water budgets necessitates diversion of surface water or the tapping of groundwater resources. The areas shown with moderate-to-high levels of unsustainable use occur over each continent and are known to be areas of aquifer mining or major water transfer schemes.

Freshwater – a natural resource which has been adopted as a human right by the UN in 2002: 'the human right to water entitles everyone to sufficient; affordable; physically accessible; safe and acceptable water for personal and domestic uses'. People depend on this resource for drinking and cooking, for irrigation of farms, for hygiene and sanitation and for power generation. The map presenting this resource only focuses on one part of the geogra...

Water is essential not only to survival but is also equally or even more important than nutrients in food production. Agriculture accounts for nearly 70% of the water consumption, with some estimates as high as 85% (Hanasaki et al., 2008a,b). Water scarcity will affect over 1.8 billion people by 2025 (WHO, 2007). This could have major impacts on health, particularly in rural areas, and thus also major impacts on farmer productivity. Althoug...

Water scarcity in terms of drought or depleted groundwater could therefore have great impacts on livestock and rangelands. These interactions are also complex. While drought can directly threaten livestock, other factors that influence water availability for livestock are seasonal droughts and socio-economic changes, such as permanent settlement and occupation of seasonal pastures by people other than pastoralists, availability and quality...

According to Population Action International, based upon the UN Medium Population Projections of 1998, more than 2.8 billion people in 48 countries will face water stress, or scarcity conditions by 2025. Of these countries, 40 are in West Asia, North Africa or sub-Saharan Africa. Over the next two decades, population increases and growing demands are projected to push all the West Asian countries into water scarcity conditions. By 2050, the numbe...

Environment water transport system. The water cycle consists of precipitation, vapour transport, evaporation, evapo-transpiration, infiltration, groundwater flow and runoff. Figure 1 explains the global water cycle, illustrating how nearly 577,000 km3 of water circulates through the cycle each year. A table of estimated residence times shows the approximate times that water resources exist as biospheric water, atmospheric water and so on. The w...

Because much of the world’s surface water is far from concentrations of human settlements, not all of it is readily usable. Some facts concerning global freshwater concentrations: - It is estimated that the freshwater available for human consumption varies between 12,500 km3 and 14,000 km3 each year (Hinrichsen et al., 1998; Jackson et al., 2001). - Many countries in Africa, the Middle East, western Asia, and some eastern European countries ha...

Global water type by percentage. Estimates of global water resources based on several different calculation methods have produced varied estimates. Shiklomanov in Gleick (1993) estimated that: - The total volume of water on earth is 1.4 billion km3. - The volume of freshwater resources is 35 million km3, or about 2.5% of the total volume. Of these, 24 million km3 or 68.9% is in the form of ice and permanent snow cover in mountainous regions, a...

It is difficult to determine the amount of renewable water produced internally from the total renewable water resources (external and internal). However the FAO gives a rather precise definition of this indicator. Internal Renewable Water Resources (IRWR) includes: - Average precipitation: long-term double average over space and time of the precipitation falling on the country in a year. - Surface water produced internally: long-term average an...

Glaciers and ice caps cover about 10% of the world’s landmass. These are concentrated in Greenland and Antarctica and contain 70% of the world’s freshwater. Unfortunately, most of these resources are located far from human habitation and are not readily accessible for human use. According to the United States Geological Survey (USGS), 96% of the world’s frozen freshwater is at the South and North Poles, with the remaining 4% spread over 550,000 k...

In areas where surface water is not readily available (located far from areas of need), groundwater is the primary water source. Groundwater aquifers supply an estimated 20% of the global population living in arid and semi-arid regions. Despite their widespread presence, groundwater aquifers in arid areas receive only limited or seasonal recharge, making such aquifers susceptible to rapid depletion. The Northern Sahara Basin Aquifer, for example,...

Water scarcity occurs when the amount of water withdrawn from lakes, rivers or groundwater is so great that water supplies are no longer adequate to satisfy all human or ecosystem requirements, resulting in increased competition between water users and other demands.

Most of the Sumatran orangutan's forests inland play a key role in ensuring downstream freshwater supplies, since the non-alluvial inland areas of the region tend to have very little or no underlying groundwater resources.