Water Scarcity / Water Stress

The concept of water stress applies to situations where there is not enough water for all uses, whether agricultural, industrial, or domestic; it is related to over- allocation of water, degradation of water quality and uneven utilization between riparians [Pegasys, 2010]. In terms of resource management, this should not be confused with basin complexity, which is “related to the number of riparian countries, the lack and/or unevenness of national institutional capacity (development), the presence of uncooperative riparians, and political tensions between riparians [Pegasys, 2010].

 

As global exploitation and demands on freshwater resources increase, biodiversity and the services that rivers provide are being degraded and becoming ever more scarce. In fact, water scarcity is one of the key challenges facing the world in the 21st century. The latest research reveals that at least 2.7 billion people live in basins that experience severe water scarcity during at least one month of the year [Hoekstra et al., 2012]. With an increase in the world’s population by about 80 million people a year, the resulting freshwater demand increases by about 64 billion m³/year [UN WWAP, 2009]. By 2025, 1.800 million people will be living in countries or regions with absolute water scarcity, and two-thirds of the world population could be under stress conditions (FAO).

 

As depicted in (Image 2.4-1), the per capita annual renewable freshwater will decrease considerably in many African, Middle East, and Asian countries by 2050; additionally, the percentage of the annual per capita freshwater remaining for aquatic ecosystems after accounting for human demands will diminish significantly in these areas.