The key to sufficient water supply is in our hands

Snow melt runoff and groundwater abstraction are the most used form of fresh water globally, but the supply is diminishing throughout the world. The problem is expected to worsen with ongoing climate change. Professor Björn Klöve, Director of the Water Resources and Environmental Engineering unit at the University of Oulu, offers a scientific take on the issue.

While the amount of water on our planet remains constant, the water supply and demand varies regionally. Several factors affect the availability of water, from the processes involved in the so-called hydrological cycle such as evaporation and precipitation, absorption into the earth, and drainage into the sea – to human activities such as dam construction, irrigation of arable land, and acceleration of climate change.

As Professor Björn Klöve points out, global warming both speeds up and increases the intensity of the hydrological cycle. One consequence of this is an increase in the amount of rain in regions that already experience heavy rainfall such as Northern Europe and Finland. On the flipside, traditionally dry regions may experience longer periods of drought. This includes Southern Europe, the Middle East, and parts of North America. In most regions, the effect on precipitation is uncertain such as as Poland and Ukraine that are already relatively dry regions. If these regions become drier, there will be dire economic consequences’, Professor Klöve surmises.

The vast amount of the world’s fresh water is contained in snow and ice. And it is precisely the run-off from alpine precipitation, followed by spring and summer snowmelt that is essential to agriculture and life in many large and populated river basins. Climate change has the effect of accelerating glacial melt and shifting the timing of runoff. And yet after an initial stage with runoff increase, a period of water shortage will follow.

‘One way that we can perhaps adapt to this situation is by building water storages, such as reservoirs to replace snow and glacier storages. Besides changes in runoff, the impact of intensive agriculture on water resources is a major issue. For example, according to some forecasts, the River Ganges in India will dry up. China has already instigated a research programme in the Himalayas and a large scale project is already in progress to divert the rivers to the north.’ Actions are required now to find solutions to mitigate the decreasing water supplies. In many regions, decision are needed to either increase the supply or decrease the demand for water.

Currently, farming practices and the regulation and control of waterways are some of the most important factors affecting drought in river basins. For example, significant dams are under way in Turkey which will have a major impact on the Tigris and Euphrates rivers.

‘Turkey has built some huge reservoirs and is directing water towards its agricultural regions and for use in energy production. Downstream, in Syria and Iraq, the flow of water has decreased.’

Syria’s drought issues and civil war have both been attributed to climate change, but according to Professor Klöve, water scarcity is due to overuse and control of upstream water supplies. The political aspects of water supply in the region have only served to fan the flames. ‘In part, the Iran-Iraq war of 1980 was instigated over control over the Shatt al-Arab estuary (at the confluence of the Tigris and Euphrates).’

Similar tensions can potentially develop in areas such as Central Asia, where the former soviet states of Tajikistan and Kirghizstan have the keys to control the regions water reserves or between China and India, Egypt and Ethiopia in south Asia and Africa.

‘In some cases, the decisionmakers are quick to point their finger in the direction of climate change even when political decisions, or lack of such, are often the reason to water scarcity and the global environmental deterioration.’

Irrigation of arable land could account for 25% of the rise in sea levels

Water scarcity has slowly emerged in several regions between the 20th and 40th latitudes in the northern hemisphere – from the Middle East and Central Asia to Southern Europe, North Africa, and California and the prairie states in the USA. Less research has been conducted in the southern hemisphere, but the same phenomenon has been observed in Australia.

‘Arable land, especially for produce requiring a lot of water such as rice, is cultivated in places that are not necessarily the most suitable’, Professor Klöve goes on to note. ‘And when water is pumped for use in food production, the groundwater evaporates. The water table has fallen by around 100 metres in both Spain and Greece. The evaporated water used for plant growth falls as rain in another location. It is thought that 25% of the rise in sea levels is due to irrigation.’

The situation began heading towards crisis levels with the widespread use of groundwater pumping in the 1950s. At around the same time, there was an increase in the construction of vast reservoirs and hydroelectric plants. On top of everything else, the rising global population has led to a need for more food and energy. Overpopulation is a key aspect effecting water scarcity. Many countries exporting food are in theory exporting their nature as unique wetlands, historically important rivers and lakes dry up.

‘Many countries want to produce their own food for safety reasons. Self-sufficiency is one of the factors contributing to our present water crisis. Decision-making is not holistic enough. Instead, it happens by sector – food production, security, employment...’

It is hard to identify a means of intervening in the excessive use of water. There are no global controls and the structures in place at the national level are, in many instances, far too weak. ‘The head honchos ensure that there is enough water for their own people at the expense of others going without. In theory, there is legislation in place to prevent further reductions in the volume of groundwater in Europe and, to some extent, there are some positive signs.’

A multidisciplinary approach is required to get the problem under control

Professor Klöve cites the concept of a nexus; referring to the combining and management of water, food, and energy. ‘We need far-reaching and multidisciplinary research to fully understand the natural and human processes at work – climate, hydrology, technological solutions, business structures, migration patterns, decision-making mechanisms.’

In addition to the consolidation of political institutions and legislation, more efficient irrigation systems, pumping purified wastewater into groundwater systems (Tunisia and Israel are leading the way in this matter), and diverting rivers (e.g. in Morocco and in Iran) are potential means of achieving the necessary changes, but include risks too.

‘China has constructed an extensive river diversion system. There are a lot of problems with this kind of system, though. When water is diverted to one area, others can become arid.’

But what about desalinating sea water?

‘The problem there is one of cost. Large scale desalination requires industrial-scale equipment and lots of energy. In fact, it is only being done in some island nations/resorts and the Gulf States. Water scarce regions are often found deep in the interior of a continent, or at high elevation, and the added transport cost for desalinated water makes this technology very expensive. Desalinating may become more common with lower energy costs and an increase in the use of solar energy’.

Professor Klöve is not, however, very optimistic. In his eyes, the age-old problems are likely to remain unsolved, regardless of the means employed to tackle them.

‘The big issues are population growth and the mechanism by which we tend to use all the water we can find, with the goal of making profits as high as possible’.

In comparison to the situations described in the aforementioned regions, Northern Europe, including Finland, finds itself in a privileged position. The concern, here, is not that of having sufficient water, but rather its quality, the eutrophication of waterways, and blue-green algae.

‘In Finland, we are faced with the challenge of competing desires – to produce more and more biomass through forestry at the same time as protecting our waterways. At the European level, the nitrates from pesticides and fertilisers continue to flow into the water table. Additionally, new materials such as microplastics and drug residues can also cause problems.’

 

Text: Jarno Mällinen

Last updated: 16.11.2018