For many years, experts, journalists and politicians have warned us about water scarcity. But what does this mean exactly?
First, scarcity is a relative phenomenon. It is the relation between the available water and the existing demands. While there is generally enough water in the world, its regional and seasonal distribution is uneven, so that in many areas and in certain periods of the year, many people experience a shortage of fresh water. And with population growth and climate change, these numbers will only grow.
Scientists developed different methods for measuring water scarcity. The best-known is probably the so-called Falkenmark Water Stress Index. It is based on the amount of renewable water per capita. If less than 1 700 m³ per year per person is available, people experience water stress. Less than 1 000 m³ per capita is classified as chronic water scarcity and less than 500 m³ as absolute water scarcity. The map below shows that, according to this assessment, Central Asia experiences neither water stress nor chronic or absolute water scarcity, though Afghanistan, Tajikistan and Uzbekistan are considered vulnerable, as their water availability is less than 2 500 m³ per person.
Although this indicator is widely used and can provide a general picture of physical water availability, it has some shortcomings. The water availability per person is calculated as an average and neglects uneven water distribution within a country or shortages in certain seasons. It does not account for the quality of water, which can significantly reduce the amount of actual available clean water, nor does it give information about a country's regulations for management, which are crucial for de facto access to water.
A broader indicator is the Rural Water Livelihoods Index (RWLI), which was developed by the UN's Food and Agricultural Organisation (FAO) in 2009. Its objective is to assess rural livelihoods and their links with water provision. The index includes four components: (1) services component (access to water and sanitation), (2) security component (crop and livestock water), (3) environment component (clean and healthy water), (4) entitlement component (secure and equitable water). The table shows the ranks of the Central Asian countries among the 158 assessed countries. The two upstream countries. Afghanistan and Tajikistan, got the worst assessment among the Central Asian states. Concerning the different components, in all Central Asian states apart from Turkmenistan, the entitlement component was assessed as being the weakest one. In Tajikistan, it got only 12.83 points (of 100), one of the lowest in the world. In contrast, in all states but Kazakhstan the security component was the best one, reaching more than 70 and in Uzbekistan even 86 points (of 100).[Sullivan et al. 2009.]
This shows that water scarcity is not a mere physical phenomenon, but also a result of water consumption and water usage patterns and therefore of human management. This was stated very clearly in the UNDP's 2006 Human Development Report, which was dedicated to water: «The scarcity at the heart of the global water crisis is rooted in power, poverty and equality, not in physical availability. (...) In many countries scarcity is the product of public policies that have encouraged overuse of water through subsidies and underpricing. There is more than enough water in the world for domestic purposes, agriculture and industry. The problem is that some people-notably the poor-are systematically excluded from access by their poverty, by their limited legal rights or by public policies. In short, scarcity is manufactured through political processes and institutions (...).»