The article provides an analytical overview of the state of global water resources and their use in the world. The focus is on the most important component of water resources – freshwater, which on the planet is only 2.5 % of the total. The most accessible renewable water resources are river runoff, which is distributed unevenly on the surface of the planet: Asia (32 %), South America (28 %), North America (18 %), Africa (9 %), Europe (7%), Australia and Oceania (6 %). Along with the characteristics of the known components of freshwater resources (river runoff, groundwater, glaciers), attention is also focused on trends in attracting unconventional sources (recovered wastewater or gray water, desalinated, specially collected rainwater).
The total use of fresh water in the world is only 9 % of the total river flow of the planet. At the same time, the problem of water scarcity was included in the list of the World Economic Forum 2015, as one of the global risks in terms of the potential impact on human society in the next decade. Among the causes of global water, scarcity are geographical and socio-economic. Geographical reasons are the spatial and temporal (seasonal) mismatch of the demand for fresh water and its availability. Socio-economic reasons are the growth of the world’s population, urbanization, improving living standards, changes in consumption patterns, and an increase in irrigated land. The latter has become key to the growth of global water demand.
Experts forecast that the limited access to fresh water in 2050 can be felt by 3.3 billion more people than in 2000. The article gives examples of a methodology for the hydrological assessment of water scarcity (calculation of the ratio of the volume of annual renewable water resources to the population) and the methodology of economic and geographical assessment. Other approaches to assessing water resources by creating new paradigms (water – blue, green, virtual, water footprint) have been characterized.
Throughout the history of mankind, there have been many conflicts related to water. Active water cooperation between countries today reduces the risk of military conflicts. This conclusion was made after studying transboundary water relations in more than 200joint river basins, covering 148 countries. The right to safe water and sanitation is a fundamental right of everyone (UN, 2010). Therefore, among the 17 sustainable development goals adopted by the UN for implementation for the period 2015-2030, Global Goal 6 “Clean Water and Good Sanitary Conditions” is aimed at ensuring sustainable management of water resources and sanitation for all. This will save people from diseases, and society will be given the opportunity to be more productive in economic terms.
Recent Developments in Solar Thermal Desalination Technologies: A Review
