Provision of fresh water is one of the key basic needs for a growing world population. There is much discussion in many circles about food security and how best to provide enough food for a future human population vastly bigger than today. However, to what extent is the concern regarding water provision held up on the same terms as the food security debate? What are the issues and are we planning sufficiently for the future? Are we facing a looming crisis in fresh water provision? At the very end of last century, in 1999, John Blunden of the Open University discussed these critical issues and divided concerns in to the following categories: availability, uses, impacts, regulation and quality. This post will briefly summarise his concerns whilst engaging with current issues moving forward.
The key concern behind this area is principally climate change and changing rainfall patterns, after all rainfall is the main source of fresh water and some areas of the world clearly receive much greater rainfall than others. The range between the driest and the wettest is likely to increase as time goes on. Currently, Iceland, with a population a little under 325,000 can fill a reservoir for each of its citizens, simply with rainfall. On the other hand Kuwait and UAE, with much larger populations receive very little rainfall indeed. Desalination is available and has been a commonplace practice since the 1990s. However, energy consumption during the process of desalination is a key concern for moving forward and currently renders this method not fully sustainable in the long term.
Irrigation for agriculture makes up about 75% of the use of fresh water resources. This is mainly because most surface irrigation systems are highly inefficient and about half the water used is lost through seepage or evaporation before it reaches the fields. To use one example it takes about 500 litres of rain water to produce 1kg of wheat whereas it takes over 1800 litres of water to grow 1kg of irrigated rice. The amount of water required in manufacturing is also enormous:
1 tonne of cement = 3,600 litres of water
1 tonne of paper = 27,000 litres
1 car = 38,000 litres
1 tonne of bread = 2,100-4,200 litres
1000 litres of beer = 4200 litres of water (in the UK)
Despite the seemingly profligate use of water attitudes are changing. However, this is perhaps more down to need than will. For example, once containing as much water as Lake Superior, the Ogallala aquifer, which stretches under eight Great Plains states from South Dakota to Texas, has been seriously depleted and is limited in the amount of water that is left. Ogallala was once used to grow one out of every six ears of corn grown in the USA. No longer is this the case due to excessive use and lack of long term thinking. However, improvements are being made. Drip methods of irrigation and some sprinklers are much better in terms of efficiency. Nonetheless desert settlements remain unsustainable and at high risk of being subject to future water crisis.
For countries with mature industrial manufacturing bases the question of how to dispose of polluting waste can result in extreme cases of water pollution. Both biological and chemical pollution still takes place although in many parts of the world there are now rigorous environmental rulings in place to avoid environmental pollution. It is however widely stated that 2/3 of China’s rivers are seriously polluted and 40% of Malaysia’s rivers are biologically dead. This is the case in many parts of the world. Improvements have been made, especially in rivers such as the Mersey, Thames and Trent in the UK but there remains much work to be done. Again there are improvements being recorded in terms of contamination deriving from agricultural practices but eutrophication remains an issue. The problem is that, whilst many farmers undertake comprehensive agronomic surveys prior to fertiliser application, on some farms in some areas of the world, nitrogen, phosphate and potash based fertilisers are applied too liberally so that the field crop cannot utilise them fully. The ‘green revolution’ in south east Asia has been particularly concerning in terms of adding to this pollution problem. At concentrations above 10-12 milligrams per litre nitrogenous fertilisers in ground water can cause health problems. Evidence has been gathered regarding the impacts of nitrates in ground water in the 1970s and 1980s – concentrations in the River Tomo in Japan rose by 14% during this time. In the Rhine the rise in concentrations was 29% and in the River Wear in England almost 50%. Research into correlations between this environmental effect and human health in the generation which grew up during that time is lacking.
The most significant impact of polluted water comes in the form of a range of diseases including typhoid, food poisoning and hepatitis. Water diseases pose a particular problem for women in developing countries who often bear the role of collecting water. Water pollution can also affect people through the food chain. Toxic substances that are deposited in water may be consumed by aquatic organisms, such as fish. When people consume contaminated fish, some effects of the toxicity are passed on to them, resulting in physical conditions similar to what they would experience if they came in direct contact with the substances themselves. Further, with increasing amounts of land being used for growing crops this is also adding to the amount of land being irrigated. Demand for irrigation has increased by two thirds since the 1980s.
Both water resources and demand need to managed in the future and governments need to consider creating water demand and supply strategies to plan in to the future. We must also be wary of water companies putting profit before need and legislate to ensure that those most in need do not struggle as a result of corporate interests. Pollution must be controlled and societies must not take water for granted so that it is overused beyond our means. This may be quite idealistic and I admit that the argument put forward in a short blog post is wholly insufficient to build the argument required to make a change in thinking. Nor have I discussed the issues of climate change and rainfall patterns sufficiently. Nonetheless, it is only by discussing these issues that we can raise awareness of the topics of debate and we will be able to plan ahead and ultimately avoid a future water crisis. Perhaps more inspiration for a longer post at some point.