The geography of future water challenges - Background reports

River Flood Risk

Globally, flood risks (river, coastal and pluvial) account for about one third of all losses due to natural hazards, and, over the last 30 years, economic losses have exceeded USD 1 trillion (2013 values) according to the NatCatSERVICE database of Munich Re. Not only does flooding entail a large cost for society, it is also highly disruptive and has a potentially significant impact on poorer people, aggravating the differences between rich and poor.
Socio-economic growth results in very large increases in the value of assets and number of people exposed to flooding. Even if flood protection were to be improved between 2010 and 2050 to keep pace with climate change, total global annual urban damage would increase from USD 78 billion in 2010 to USD 395 billion by 2050.

This background document is about the scientific justification of the information produced for the chapter ‘Flooding’ of ‘The Geography of Future Water Challenges’ (2018), The Hague: PBL Netherlands Environmental Assessment Agency.

• download the report

Hydropower and water

Hydropower has become an important source of electricity across the world. However, studies have also shown that it is vulnerable to climate change. On a global scale, hydropower generation has increased by about 50%, since 1990. Long-term scenarios project hydropower demand to increase by 80% by 2050. On the one hand, hydropower has proven to be a clean, reliable, and flexible technology for producing electricity and, as such, is an attractive alternative to fossil-fuel-based technologies. On the other hand, the projected expansion of hydropower may have consequences for humans and nature, especially on a regional scale; about 8 million people currently live in areas with high hydropower potential.

This background document is about the scientific justification of the information produced for hydropower in the chapter ‘Water-related energy production’ of ‘The Geography of Future Water Challenges’ (2018), The Hague: PBL Netherlands Environmental Assessment Agency.

• download the report

Water, Migration and Conflict

Water plays a critical role in social and economic progress, on global, national, regional and local levels. Sufficient and clean water is a precondition for development, and water-related projects are often stimulating cooperation between countries, communities or individuals. However, a combination of projected population growth, economic development and climate change may increase water-related risks for sustainable livelihoods, and in more exceptional cases for migration and political stability.

• download the report

Water scarcity

Water scarcity, the inability of water resources to meet water demand, is considered to be one of the most important global risks for society. Projected increases in water demand due to changing lifestyles and a growing population, as well as projected changes in hydro-climatic conditions, are expected to further increase both the probability of water scarcity events, as well as their societal impact. Areas with relatively high water scarcity risks are predominantly found in the Middle East, Southeast Asia, and northern Africa. The objective of this background document is to provide an estimate of global water scarcity with respect to the supply from rivers and streams (surface runoff) for 2010 and 2050.

• download the report

Health, nutrients and water quality

Waterborne diseases are responsible for very high mortality in many developing, poor countries. These diseases are mainly due to the lack of improved sanitation. The main option to improve health is to construct sewer systems to remove human waste from households. This negatively affects ecosystems, when surface waters become polluted with discharges of untreated organic waste that are too high. Waste water treatment will reduce these high loads. The other loads of nutrients onto surface water are diffuse discharges from agriculture due to high fertiliser use. The combination of nutrient discharges from agriculture and households results in eutrophication, leading to the massive growth in algae and water plants in freshwater and marine water systems, poisoned drinking water, massive fish kill in aquaculture, and less tourism due to algae blooms.

This background document is about the scientific justification of the information produced for in the chapter ‘Water pollution and human health’ of ‘The Geography of Future Water Challenges’ (2018), The Hague: PBL Netherlands Environmental Assessment Agency.

• download the report

Freshwater availability

Globally, freshwater resources are increasingly affected by climate change and taxed by human water demand as a result of population growth and improving living standards. An intrinsic part of these socio-economic changes are shifts in land use, including a growth in irrigated area to secure crop yields in the more arid regions of the world. Yet, these changes in environmental factors interact with the global water cycle. This, in turn, leads to shifts in both water use and water availability. In time, this jeopardises water and food security, and threatens biodiversity and supporting ecosystems. On a global scale, availability of renewable water resources exceeds demand multiple times. However, it should be noted that water availability varies widely in both space and time. Irrigation water demand is proportionally high in dryland areas around the world—where renewable water resources are scarce—and the seasonal water demand is often out-of-phase with the supply.

This background document is about the scientific justification of the information produced for in the chapter ‘Water and food production’ of ‘The Geography of Future Water Challenges’ (2018), The Hague: PBL Netherlands Environmental Assessment Agency.

• download the report

Water, climate and aquatic-biodiversity risks

Currently, freshwater ecosystems—rivers, lakes and wetlands—are already seriously under threat For example, since 1900, nearly 70% of the world’s wetlands have been lost, 70% of the world’s rivers have become highly or moderately fragmented, many of the world’s lakes, especially in the temperate and tropical regions, are heavily impacted by eutrophication, and the loss of aquatic species is continuing at an even faster rate than that of terrestrial species. Climate change and socio-economic developments lead to losses not only of natural habitat and biodiversity, but also of important ecosystem services as well as cultural services for recreation.

This background document is about the scientific justification of the information produced for the chapter ‘Ecological quality of aquatic ecosystems’ of ‘The Geography of Future Water Challenges’ (2018), The Hague: PBL Netherlands Environmental Assessment Agency.

• download the report

Water, climate and food production

Safeguarding the future production of food for a growing population under a changing climate poses a major challenge. The availability of fresh water is one of the most important conditions for agricultural production and, therefore, a prerequisite for ensuring a sufficiently high food production level. A shortage of water directly leads to a loss in crop production.
Population and economic growth will lead to a higher demand for food, and will therefore impact the cropland extent and total volumes of water needed for agriculture.
Regions where crop production is not very reliable due to a high variability in water availability are particularly vulnerable when they do not have sufficient water storage capacity or the means to import food. Regions that fully depend on rainfed agricultural production (mostly dryland areas), generally, are more sensitive to variability in water availability than those with irrigated croplands.

This background document is about the scientific justification of the information produced for in the chapter ‘Water and food production’ of ‘The Geography of Future Water Challenges’ (2018), The Hague: PBL Netherlands Environmental Assessment Agency.

• download the report