Water scarcity is one of the greatest threats faced by humanity of our time – in 2019, more than two billion people experience high water stress (UN-Water 2019) and approximately four billion people suffer from severe water scarcity for at least one month per year (Mekonnen and Hoekstra 2016). This worsening problem increases the risk of international conflict over water resources breaking out, given that there are over 270 transboundary river basins, and three-quarters of UN Member States share at least one river or lake basin with a neighbour (UN News 2017). These internationally shared water resources are the primary source of fresh water for about 40 per cent of people worldwide (UN News 2017), which further attests to the importance of water cooperation on the global scale.
The increasing severity of water scarcity – fuelled by climate change (Intergovernmental Panel on Climate Change 2008) – along with growing recognition of the threat this poses to global peace and human security, has given rise to ‘hydro-diplomacy’ (or ‘water diplomacy’) (Schmeier 2018). This important branch of foreign relations can be defined as the use of diplomatic instruments to make shared water sources a domain for peace and cooperation rather than for conflict.

In 2017, UN Secretary-General António Guterres highlighted the importance of hydro-diplomacy in an address to the UN Security Council, stating that “water, peace and security are inextricably linked” and that “water is and should remain a reason for cooperation not conflict” (UN News 2017). Moreover, the UN has officially highlighted the need for international cooperation in water management in UN Sustainable Development Goal 6 of “Clean water and sanitation”, for which one target involves implementing “integrated water resources management at all levels, including through transboundary cooperation as appropriate” by 2030 (United Nations 2019).

Achieving cooperative hydro-diplomatic relations depends on access to accurate, timely and reliable information about water resources (European Space Agency (ESA) 2019b). Earth Observation data from satellites has dramatically improved our ability to measure and monitor changes in rivers, lakes and reservoirs, and allows us to more clearly see the effects of climate change which are intensifying our water scarcity challenges (ESA 2019a). Remotely-sensed data is particularly necessary for water management in regions that do not have well-developed land infrastructure in place to measure changes in bodies of water.

Space-derived data play a crucial role in water diplomacy by providing objective and unbiased information from which knowledge about water resources can be derived. This forms the basis of informed decision-making regarding water management and is therefore important in the case of managing water resources that are located across national borders. Transboundary water management can be achieved much more efficiently and effectively when riparian states exchange data, as many states differ in their capacity for data collection and analysis, so information-sharing allows for a more complete picture (Lawford et al. 2013).

In addition, information acquired from space-based technologies underpins many cooperative transboundary water projects – such as Brazil and Paraguay’s Itaipu dam – which can play a significant role in advancing hydro-diplomatic relations. Agreeing to jointly construct and operate Itaipu dam, which is located on the Paraná river that borders Brazil and Paraguay, helped the two countries to resolve a border dispute (Blanc 2017). Itaipu is now the world’s largest renewable energy generator, and its output is shared by both countries (Itaipu Binacional 2019b). The 40 stations that make up Itaipu’s Hydrometeorological Telemetry System read data from sensors and relay them to the power plant in part via satellites, meaning that space-based technologies facilitate its operation (Itaipu Binacional 2019a). Furthermore, data from satellite images provide important information for the forecast, monitoring and control processes of the plant’s hydro-energy generation (Itaipu Binacional 2019a).

Although internationally shared water resources can undoubtedly pose a significant threat to global peace, they also present opportunities for advancing relations between neighbouring states. Agreements about the sharing of transboundary water resources can prove to have great resilience and can bring states together, even when they disagree on other issues. For instance, the Mekong River Committee (now known as the Mekong River Commission), survived throughout the Vietnam War, with data continuing to be exchanged among the Committee’s member states even as they were legally at war with one another (Wolf 1998).

Another resilient water-sharing agreement is the Indus Waters Treaty, which India and Pakistan ratified in 1960 to manage the distribution of water from the Indus System of Rivers on which both countries are dependent. The Treaty is often considered one of the most successful examples of transboundary water-sharing agreements, with its dispute resolution mechanism having facilitated the settlement of disagreements such as that regarding the construction of the Salal dam in 1978 (Akhtar 2010). The framework of the Treaty provides a promising opportunity for cooperation to be achieved in the sharing of water data between the parties as well as proposed plans for development projects on the Indus Basin rivers (Akhtar 2010). The Indus Waters Treaty has survived three wars between the two countries and has played a critical role in improving water security in both India and Pakistan, with information-sharing constituting a central aspect of this (The World Bank 2018).

Recognising the significant applications of space-derived data to water management, the UN Office for Outer Space Affairs plays an active role in assisting practitioners from developing countries to access and utilise geospatial technologies and remotely-sensed data to more effectively manage their water resources. Among the Office’s activities that foster capacity building and knowledge exchange are the Space for Water project and Space-based information for Disaster Management and Emergency Response (UN-SPIDER) programme and their respective web portals. With the goal of assisting Member States to take full advantage of space-based information, UN-SPIDER runs Technical Advisory Missions and training programmes in developing countries.

Improving the capacity of states around the world to access and apply space-derived data to water management will put us on course to strengthen water security and to mitigate the threats posed by water scarcity. By their very nature, transboundary water sources – on which so many communities around the world depend – require bilateral or multilateral hydro-diplomatic cooperation to manage. Thanks to the timely and accurate data provided by space technologies, states that share transboundary rivers or basins will be better equipped to implement hydro-diplomacy and use their shared water resource as a tool for cooperation rather than conflict.