Increased water-recycling and improved irrigation techniques among six strategies identified as key to successfully reducing global water scarcity
Water scarcity is not a problem just for the developing world. In California, legislators are currently proposing a $7.5 billion emergency water plan to their voters; and U.S. federal officials last year warned residents of Arizona and Nevada that they could face cuts in Colorado River water deliveries in 2016.
Irrigation techniques, industrial and residential habits combined with climate change lie at the root of the problem. But despite what appears to be an insurmountable problem, according to researchers from McGill and Utrecht University it is possible to turn the situation around and significantly reduce water scarcity in just over 35 years.
In a new paper published in Nature Geoscience, the researchers outline strategies in six key areas that they believe can be combined in different ways in different parts of the world in order to effectively reduce water stress. (Water stress occurs in an area where more than 40 percent of the available water from rivers is unavailable because it is already being used – a situation that currently affects about a third of the global population, and may affect as many as half the people in the world by the end of the century if the current pattern of water use continues).
The researchers separate six key strategy areas for reducing water stress into “hard path” measures, involving building more reservoirs and increasing desalination efforts of sea water, and “soft path” measures that focus on reducing water demand rather than increasing water supply thanks to community-scale efforts and decision-making, combining efficient technology and environmental protection. The researchers believe that while there are some economic, cultural and social factors that may make certain of the “soft path” measures such as population control difficult, the “soft path” measures offer the more realistic path forward in terms of reducing water stress.
(The details about each of the six key strategy areas are to be found below.)
“There is no single silver bullet to deal with the problem around the world,” says Prof. Tom Gleeson, of McGill’s Department of Civil Engineering and one of the authors of the paper. “But, by looking at the problem on a global scale, we have calculated that if four of these strategies are applied at the same time we could actually stabilize the number of people in the world who are facing water stress rather than continue to allow their numbers to grow, which is what will happen if we continue with business as usual.”
"Significant reductions in water-stressed populations are possible by 2050,” adds co-author Dr. Yoshihide Wada from the Department of Physical Geography at Utrecht University, “but a strong commitment and strategic efforts are required to make this happen."
Strategies to reduce water stress
1. Agricultural water productivity could be improved in stressed basins where agriculture is commonly irrigated. Reducing the fraction of water-stressed population by 2% by the year 2050 could be achieved with the help of new cultivars, or higher efficiency of nutrients application. Concerns include the impacts of genetic modification and eutrophication.
2. Irrigation efficiency could also be improved in irrigated agricultural basins. A switch from flood irrigation to sprinklers or drips could help achieve this goal, but capital costs are significant and soil salinization could ensue.
3. Improvements in domestic and industrial water use could be achieved in water-stressed areas through significant domestic or industrial water use reduction, for example, by reducing leakage in the water infrastructure and improving water-recycling facilities.
4. Limiting the rate of population growth could help in all water-stressed areas, but a full water-stress relief would require keeping the population in 2050 below 8.5 billion, for example, through help with family planning and tax incentives. However, this could be difficult to achieve, given current trends.
5. Increasing water storage in reservoirs could, in principle, help in all stressed basins with reservoirs. Such a strategy would require an additional 600 km3 of reservoir capacity, for example, by making existing reservoirs larger, reducing sedimentation or building new ones. This strategy would imply significant capital investment, and could have negative ecological and social impacts.
6. Desalination of seawater could be ramped up in coastal water-stressed basins, by increasing either the number or capacity of desalination plants. A 50-fold increase would be required to make an important difference, which would imply significant capital and energy costs, and it would generate waste water that would need to be disposed of safely.
To read the Nature Geoscience article: http://www.nature.com/ngeo/journal/v7/n9/full/ngeo2241.html?WT.ec_id=NGEO-201409
The research was funded by: Natural Sciences and Engineering Research Council of Canada and the Canadian Institute for Advanced Research.
McGill University, Media Relations
Prof. Tom Gleeson
Christopher Chipello | newswise
A 3-D look at the 2015 El Niño
29.05.2017 | NASA/Goddard Space Flight Center
'Tiny clocks' crystallize understanding of meteorite crashes
29.05.2017 | University of Western Ontario
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy
29.05.2017 | Statistics