Global Freshwater Availability Trends

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Key Points

The NASA Gravity Recovery and Climate Experiment (GRACE) satellite mission tracked trends in global freshwater supplies from 2002 to 2016. An analysis of the satellite data identified 19 hotspots where there were dramatic increases in water stress. Some of that stress could be alleviated by the application of green solutions, such as wastewater recycling, to reduce the reliance on grey infrastructure, such as reservoirs. Countries need to develop multilateral, co-operative management practices and initiatives for shared water resources, including the fostering of transboundary water sharing agreements.

Summary

Freshwater availability is vital for the survival of any country. A lack of freshwater can hinder agricultural productivity and industrial and economic development. Scarce amounts of surface water have led to the overuse of groundwater, further straining water supplies and adding to environmental degradation. A study, based on data collected from the GRACE satellites, tracked the global trends of freshwater availability between 2002 and 2016.

An analysis of the satellite data identifies 19 hotspots that experienced dramatic water depletion over those 14 years. The analysis suggests that north-western China, northern and eastern India, North Africa and the northern Middle East are most likely to experience the greatest food and water threats by 2050. The study, however, also located regions where freshwater availability increased.

To overcome food and water security threats there is a need to improve the level of management and governance, from the local to the international level. The development of multilateral, co-operative management arrangements, practices and initiatives for shared transboundary water resources and a shift to green solutions, will be crucial to the future of water security within those regions.

Analysis

The global availability of freshwater is constantly fluctuating. The United Nations estimates that by 2050, five billion people could suffer from water shortages. The global availability of freshwater is affected by various stressors, including: climate change, population growth and human-induced activities, such as deforestation and unsustainable agricultural practices. The stressors have increased water demand and put pressure on freshwater sources, including: rivers, lakes, aquifers, glaciers and reservoirs. The increased stress on freshwater bodies requires adequate global, sustainable, management measures, which has been raised as a key environmental challenge of the 21st century.

Groundwater is a vital source of water for agricultural, industrial and domestic activities. It also helps to replenish streams, lakes, wetlands and other water-based ecosystems. A stable source of freshwater is essential for the maintenance of regional food supplies, human and ecosystem health, energy generation and the avoidance of social unrest.

A paper published in Nature analyses the results of a recent NASA global freshwater availability study. The analysis accumulated data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellite mission, which tracked trends in global freshwater supplies from 2002 to 2016. The study categorises the drivers of changing freshwater availability into natural variability from year to year, unsustainable groundwater consumption and climate change. The analysis identifies 19 water depletion hotspots. Other areas show the accumulation of freshwater due to hydrological changes. Simply put, those changes indicate that wet land areas, including both the high latitudes and the tropics, are getting wetter and dry land areas are getting dryer. If that trend continues, rainfall will become sparser in dry regions, which, in turn, will increase their reliance on groundwater, further straining that resource.

Agricultural irrigation is one of the most intensive uses of groundwater, especially in semi-arid regions. The OECD states that groundwater is used for over 40 per cent of global irrigation and is an indispensable input for food production. Amid climate change, where drought is severe and continual development and population growth are leading to polluted water bodies, groundwater is often a reliable alternative to surface water sources. In many parts of the world, current irrigation practices are unsustainable and the continued extraction of groundwater for such practices could lead to poorer overall security outcomes.

Industrial activities are also a cause for concern. Population growth and migration to cities has led to an increasing rate of industrial development and increased levels of water pollution. Globally, 80 per cent of municipal and industrial wastewater is discharged without treatment. Untreated wastewater gets funnelled back into freshwater bodies, contaminating the already limited supply. The decreasing availability of freshwater in many of the world’s irrigated agricultural regions, as outlined in the study, needs further analysis to assess the likely future security outcomes.

Regions with Increased Freshwater

Increased freshwater availability is mostly due to anthropogenic influences and climate change. Due to changes in the global hydrological cycle, freshwater is accumulating in far-northern North America, Eurasia, India and in the wet tropics of Australia. Freshwater has increased in those specific areas due to an increase in rainfall, a surge in dam construction (which increases the water storage capacity of the region surrounding the dams) and an increase in glacial melt flows.

The accumulation of water in the northern Great Plains of North America is the result of above average precipitation for nine of the 14 years covered by the GRACE mission, including flooding in 2010-11. Similarly, many of the lakes in the Tibetan Plateau also accumulated water due to increased precipitation levels, as well as an increase in water flow from glacial melt. The increase in east-central China, however, was caused by the surge in dam construction that occurred throughout the region between 2002 and 2016.

The study states that in some regions the increase in freshwater availability was probably caused by natural variation in rainfall. In central and southern India, for instance, the increased availability of water was caused mainly by natural variation in the amount of monsoonal rain. That observation was consistent throughout the course of the GRACE mission, mainly in the mountainous and tropical regions of the world. In those regions, periods of lower than average rainfall were followed by longer periods of greater than average rainfall. Between 2001 and 2005, for example, the Amazon Tropics in Brazil received less than average rainfall, followed by greater than average rainfall for six of the next ten years, as the water cycle in the region intensified. The increase in glacial melt flows on the Tibetan Plateau, which led to the filling and replenishing of nearby water bodies, further increased freshwater availability in that part of the world.

Greater than average rainfall may, at first, seem like a positive development. As surface water availability increases, due to more rainfall and increased storage in dams, agricultural, industrial and domestic consumers reduce their reliance on groundwater. More intense rainfall, increased glacial melt flows and dam construction can also have negative impacts, however. Recent floods in East Africa have caused rivers and dams to overflow and damage infrastructure; displacing thousands of people and sparking fear of water-borne disease outbreaks.

Dams can also have negative environmental and agricultural impacts. During the construction of dams, large areas of natural vegetation are cleared, the flows of rivers are altered and the flow of nutrients downstream is reduced. Those changes can subsequently lead to increased levels of soil salinity, reduced levels of water availability and the loss of biodiversity, all of which can affect food security. The construction of 22 dams in Turkey over the last 30 years, for instance, has decreased the flow rate of freshwater into Iraq and Syria. Those two countries have been hit by severe drought and the decreased water flow in the Tigris and Euphrates rivers has further magnified the issue of water availability, leading to an increased reliance on groundwater for the irrigation of crops and domestic water needs. These water security stressors are also linked to social unrest in the forms of protests and political instability, particularly in Iran.

What could be done?

Regions that experienced an increase in freshwater availability during the course of the GRACE mission and are forecast to experience a further increase in rainfall, must show initiative in developing policies and projects to increase their resilience. They must focus on water security, to ensure access to an adequate future water supply. There is a great opportunity for such regions to capture and sustainably utilise their supply. On the other hand, the opportunity could also be overlooked or squandered, causing detrimental environmental, social and political turmoil.

Regions with Decreased Freshwater

By 2050, the regions that are most likely to be water stressed include parts of north-west China, north and east India, and the northern parts of the Middle East and North Africa. Those regions all have similar characteristics. They have: comparable climates, growing populations, a high dependence on agriculture and are undergoing rapid economic development. Some of them are also prone to political instability and regional conflict.

Xinjiang, a province in north-west China, and the greater Beijing region both experienced intense depletion of freshwater during the GRACE study period. Rapid levels of development and a heavy reliance on groundwater for agriculture mostly explain the huge groundwater losses. Xinjiang is one of the poorer provinces of China, with an estimated 1.6 million people living below the poverty line in the southern part of the province alone. The lack of water and outdated irrigation systems have weakened the agricultural development of the region, causing it to miss out on the economic boom that much of China has experienced over the past 30 years.

Agriculture is also an important economic sector in the greater Beijing region, which is experiencing human-induced water depletion. The stressors of population growth and the migration of people to Beijing have propelled urban development and increased the demand for food. The increasing demand for food has led to the expansion of agricultural irrigation within the greater Beijing region, putting further stress on water resources there.

Agricultural production in eastern China is hitting its limits. To gradually increase food production, alleviate food supply restrictions and maintain food security, there is a greater need to develop the western provinces of China. Consequently, the Chinese Government has turned its focus to the development of the Xinjiang region. Those development efforts have taken the form of agricultural development policies and the growth of its water-intensive cotton industry. The Chinese Government recently announced that it will spend up to US$300 million ($402 million) to improve outdated irrigation systems and promote water-saving technology, to boost agricultural production. The irrigation systems will enhance the development of the region and possibly reduce social and political tensions. As the availability of water within the province declines, the policies and agricultural infrastructure investments may be limited in their potential to overcome the current security issues, which are driven by more than just water insecurity.

The Nature analysis also points out that freshwater availability in Bangladesh, Myanmar, and northern and eastern India has declined. The loss of freshwater is attributable to a decrease in monsoon season precipitation in the eastern region and intense levels of surface, especially flood, irrigation for water intensive crops, such as rice and wheat. This region is the third-most heavily irrigated area covered by the study. It is also home to the highest density of rural poor in the world, who are highly dependent on agriculture for their food and livelihood security. The region is also highly susceptible to climate change, which was evident in the results of the GRACE mission, as the region experienced years of alternating drought and floods between 2002 and 2016.

Agriculture is the backbone of the region. Crop yields and the water supply will be negatively impacted as population growth and severe climatic pressures continue to increase. As this is one of the most heavily irrigated regions in the world, freshwater availability will continue to decline unless water conservation technologies are more widely adopted. The increasing severity of weather events, driven by changes in the hydrological cycle, is a growing concern, as Indian crop yields are highly variable from year to year. This affects food security to the point where unexpectedly severe weather events, such as flash floods, could potentially wipe out food supplies. Not only could it reduce the quantity of readily available food, but it could also have an economic impact on the whole country. The reduction in crop supply would see India increasingly rely on food imports, which could potentially lead to trade imbalances. Similar conditions have occurred in Egypt.

Of the four regions that are most likely to experience severe food and water threats by 2050, the Middle East, specifically the northern part of the region encompassing Turkey, Syria, Iraq and Iran, will be most threatened. This is reiterated by the World Bank, which states that the Middle East-North Africa region is a global hotspot for unsustainable water use. This especially involves groundwater, where more than half of current water withdrawals exceed natural rates of water recharge. It is also important to note that, by 2050, the region is expected to have the greatest economic loss from climate-related water scarcity. This region is not as heavily irrigated as India or China, but there is a high degree of competition for already scarce water resources.

The northern Middle East has a complicated water history compared to other regions. The complication and competition arises in the form of dams, severe drought and regional instability. The dams have altered river flow patterns restricting the flows of freshwater between regions. Furthermore, drought has drastically increased the regional reliance on groundwater, as water availability from other sources, like rivers, has diminished. Over the past 30 years, Turkey has constructed 22 dams upstream on the Tigris and Euphrates Rivers. This has decreased the flow rate by at least 40 per cent in Iraq and Syria. The reduced flow rates in the rivers and the long-term drought have combined to increase the region’s reliance on groundwater supplies for domestic and agricultural needs. In Iran, for example, 12 of the country’s 31 provinces could exhaust their aquifers within the next 50 years, with surface water runoff expected to decline by 25 per cent by 2030. The Natureanalysis, however, has not accounted for the impact of regional instability and conflict on freshwater supplies.

In the Middle East, water is often used as a tool or weapon to advance state agendas. In Iraq, water has been used to secure political and military aims, further destabilising the country. In one example, drawn from local accounts, the governor of Najaf diverted more water than allocated to his own farmers to boost his popularity. A series of interviews, conducted by National Geographic, also state that ISIS crafted a narrative that suggested that the lack of rain in Iraq was not due to climate change but rather to a government plot to drive out opposing ethnic groups. ISIS used this as a means of recruitment and to aggravate tensions. Iran, the third-largest dam builder in the world, also uses water for political motives. Rivers dammed across the country divert water to key areas, in efforts to gather support from important parts of the country. The politicisation of water resources and distribution could potentially result in severe conflict. Some tribes in southern Iraq, for instance, have warned the Iraqi Government that a “war” could erupt in the absence of suitable measures to resolve their water security concerns.

Some regions of Africa have also experienced freshwater loss, most notably across the arid north of the continent in Algeria, Libya and Egypt. Although the negative trend was weak compared to other regions of the world, it is important to note that precipitation levels were seven per cent above regular levels between 2002 and 2016. From this it can be assumed that the extraction of groundwater is the cause of the decline. Population growth and migration to cities has fuelled economic development across the region and led to an increase in the use of agricultural irrigation. Those practices have contributed to the over-extraction of groundwater and the subsequent decline in freshwater availability.

As the region develops and continues to industrialise, living standards will improve, which will further increase demand for water, food and energy. Additionally, rising temperatures produced by climate change will see evaporation rates increase and precipitation decrease. This process will prolong droughts and increase the chance of flood events. The region has also been scoured by internal conflict and political instability, leading to insufficient governance of water resources. Libya and Algeria, in particular, have both experienced greater levels of political instability and violence recently.

Implications

Evidently, there are specific implications associated with diminishing freshwater availability in the regions discussed; however, there are several overarching stressors that are constant throughout all regions. The biggest challenges include: high population growth rates; unsustainable levels of groundwater extraction and management, mainly for agricultural irrigation; and increasing levels of industrial development and regional instability. All the regions discussed above are also situated in the semi-arid zones that are most likely to be affected by climatic and hydrological changes, meaning that the global problem of declining freshwater supply is going to get worse, especially in semi-arid climates.

These factors have reduced water security levels within the region, increasing demand and the reliance on groundwater supplies to sustain current industrial, domestic and agricultural activities. As population growth, industrial and economic development and consumption patterns change, water is going to be constantly in demand. Consequently, without stable sources of water countries will be affected economically, socially and environmentally. A reduction in agricultural productivity, which is often associated with a reduction in water availability, increases a country’s reliance on food imports. That reliance on imports, in turn, increases the reliance on global commodity prices, which can potentially affect a country’s terms of trade.

In some parts of the world, reliance on overseas food supplies has contributed to social unrest and political turmoil – for example, the events that occurred in Egypt in 2010. Egypt relies heavily on overseas supplies of wheat to meet domestic demand. When Russia banned the export of wheat following a drought, that decision contributed to pressures that caused increases in global prices. That spike in prices contributed directly to social unrest in Egypt, which, in turn, drove the Arab Spring uprisings. In addition to the economic and social disruptions, overuse of groundwater can also result in: the lowering of the water table; increased costs as more energy is consumed; reduced supplies of surface water; and an increase in the salt content in soils, reducing the arability of farmland.

Water security is a multidimensional problem. A recent report by US intelligence agencies, concluded that ‘water problems – when combined with poverty, social tensions, environmental degradation, ineffectual leadership and weak political institutions – contribute to social disruptions that can result in state failure.’ Therefore, without the correct implementation of policy, water management practices, technology and infrastructure, countries with a growing reliance on groundwater could, by 2050, become failed states, as freshwater availability is increasingly strained.

Recommendations to Improve Water Supplies

Moving toward 2050, there will be many regions of the world facing severe water shortages, as already experienced in parts of South Africa. To mitigate the stresses and stark implications that come with the depletion of freshwater availability, a few key actions can be taken. Those actions include: improved policies that encourage the adoption of water efficient crops; sustainable agricultural infrastructure; the recycling of wastewater; and, most importantly, a co-operative management of shared water resources, as well as the fostering of transboundary water sharing agreements.

Agriculture is the biggest global water consumer and is a rising source of water pollutionand thus change in this industry will be the key to water conservation. The GRACE report calls for the wider adoption of conservation agriculture. This would require: greater use of rainwater and rainwater harvesting for irrigation, rather than drawing exclusively on natural water bodies; crop rotation to maintain soil cover; increased crop diversification; and adopting practices to reduce evaporation and run-off.

There is also a need to better utilise green infrastructure. Instead of replacing or building more reservoirs to supply cities with water, a greater uptake of green solutions is needed. These could be financed by green bonds and increased payments for ecosystem services, such as forest or wetland conservation initiatives. There is also a huge opportunity to meet water demand through the recycling of wastewater, as 82 per cent of the world’s wastewater is not recycled. Private and public institutions could both begin to develop green infrastructure and implement practices that take advantage of this opportunity.

Throughout history the world has continually faced the problem of ensuring water security. There are several regions that by 2050 will be greatly threatened by increased water stress. Therefore, to mitigate this threat an increased level of management, from a local to a global level, is essential.