Report Assesses Risks to World’s Shared River Basins

By Alex de Sherbinin

A major report on the status and future threats to the world’s 286 transboundary river basins has been released by a consortium of institutions led by the UNEP-DHI Center for Water and Environment and including the Earth Institute’s Center for International Earth Science Information Network (CIESIN). The report, funded by the Global Environmental Facility’s Transboundary Waters Assessment Program, covers transboundary river basins that comprise more than 40 percent of the earth’s population and land area in 151 countries. Transboundary river basins cross international borders and are shared by two or more countries, which often makes managing them more challenging.

CIESIN’s contribution to the project was to author a socioeconomic chapter, for which we calculated three indicators: economic dependence on water resources, societal well-being levels, and the risk of climate-related hazards (see map figure). The first indicator measures the proportion of economic activity—as measured by agricultural and industrial activity—within the basin compared to outside the basin, for the countries that share the basin, with higher proportions indicating higher dependence on the water resources of that basin. The second indicator includes a suite of standard development indicators: infant mortality rates, access to water and sanitation, literacy rates and economic inequality (gini coefficients). The third indicator is a measure of economic assets exposed to floods and the variation in inter-annual river flow.

The socioeconomics chapter had the following main findings:

1. Climate-related risk is linked to economic dependence on transboundary water resources and low well-being: Basins with high economic dependence, low levels of societal well-being and high exposure to floods and droughts have the highest climate-related risks. These basins are found mostly in Africa and South and Southeast Asia. They include, at the highest levels of vulnerability, the Limpopo, the Ganges and the Mekong.
2. Well-being and governance capacity to address disasters are linked: In basins where societal well-being is low, governance capacity (measured by Stockholm International Water Institute) to address vulnerability to floods and droughts is also likely to be low. Women, children and people with disabilities are groups particularly vulnerable to floods and droughts. Attention might be warranted to assess governance needs and increase capacity in these countries and basins.
3. Larger basins have greater economic dependence: Larger basins tend to have higher levels of economic dependence on basin water resources, due mainly to the fact that larger basins are likely to include greater portions of the population and area. The 14 basins with the highest levels of economic dependence collectively comprise a population that is almost 50 percent of all transboundary basins (almost 1.4 billion people). These larger basins may be harder to manage from a transboundary point of view because of the number of countries and diversity of priorities. Management becomes even more critical to safeguard socioeconomic well-being in these countries.

The table below summarizes the  basins with the highest risk for the three factors. Of the 20 basins listed at least once, all but five are located in Africa.

Some of the key findings from the report include:

1. The threat to freshwater biodiversity is global. Extinction risks are moderate to very high in 70 percent of the area of transboundary river basins. However, local-level, tailored solutions are needed to address risks of species extinction.
2. The construction of dams and water diversions is in progress or planned in many transboundary river basins, often without adequate international water cooperation instruments. While many transboundary agreements exist, more effort is needed to update them to reflect modern principles of transboundary water management. This includes the obligation to not cause significant harm to the river and the areas surrounding it, and the commitment to principles of cooperation and information exchange.
3. Risks are projected to increase in the next 15–30 years, particularly in four hotspot regions: the Middle East, Central Asia, the Ganges-Brahmaputra-Meghna basin, and the Orange and Limpopo basins in Southern Africa. Action should be taken now to reduce future impacts and subsequent costs.

The assessment serves a number of purposes. This includes identification of river basins at risk from a variety of issues, encouraging knowledge exchange and increasing awareness of the importance of the transboundary waters and their current state.

More information on transboundary river basins can be found at http://twap-rivers.org/. The website includes links to the Final Technical Report, Summary for Policy Makers, and Interactive Results Portal with global maps of assessment results and indicator metadata sheets.

Alex de Sherbinin heads the Science Applications Division of the Center for International Earth Science Information Network and serves as deputy manager of the NASA Socioeconomic Data and Applications Center.