| dc.description.abstract | Presently only 10% of maximum available blue water resources, is used by the three consumptive categories, the agricultural, the industrial and the domestic. Recent studies have showed that water demand is expected to increase within the next decades due to constantly growing population, whereas the available freshwater resources are not likely to increase with the same rate and this makes the appropriate management of freshwater resources urgent. This study assessed the amount of pressure put on available blue water resources by using the Water Scarcity Index. The monthly water demand for the year 2000 as benchmark year was calculated and was contrasted against 44 years (duration: 1958-2001) of a long-term climate based on ERA-40 and CRU TS 2.1 meteorological data sets. We also estimated for the year 2000 the additional fresh water resources (e.g. desalinated water use and groundwater abstraction).
The results of this study indicate that about 1.67 to 2.27 billion people live under moderate to high water stress but it is subject to change, depending on whether we are looking at a monthly or a yearly temporal resolution. Our results compared to the results of other studies, showed that about 0.21 billion less people live under moderate to high water stress. This could practically mean that past studies overestimated the amount of people living under moderate or high water stress.
This assessment also revealed those regions globally, which in the year 2000 experienced high water stress. In January the regions which suffer from high water stress (WSI>0.4) are located mostly in parts of North India, East Australia, Central Asia and Central Africa. The situation in February stays the same but regions in Southern India, West Australia and East Asia show the same behavior like the rest regions in January. March and April are months that high water stress occurs in the western parts of India, East China and Central Africa. Western parts of North America deal with high water stress in several months of year 2000 (May, June, July and August). In the summer months (June to September in the Northern Hemisphere and December to March in the Southern Hemisphere) regions located around Mediterranean Sea (Spain, Italy, Greece, Algeria and Morocco), North India, Pakistan and East China face high water stress conditions. In the rest months of the year the problem of high water stress is visible in South Africa, central parts of South America, East Europe and East Asia (regions in China and Mongolia). | |
