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Ganges, Indus and Brahmaputra basins showed the lowest levels of governance and environmental performance, potentially increasing water security risks, according to a new study.
Overall, India got a middle-rank in governance, which is calculated after considering voice accountability, political stability, government effectiveness, regulatory quality and the rule of law. The country was ranked “very low” in terms of environmental performance and “very high” in hazard category (considers aspects of governance and environmental performance), the study published in the journal Nature Water noted.
“Some Indian basins, such as the Krishna, Ganges and Indus, present a very high level of risk, given that the continental areas where their rainfall originates belong to countries with low to medium environmental performance and governance levels. Additionally, these basins depend significantly on continental moisture sources,” Fernando Jaramillo, associate professor in physical geography at Stockholm University and one of the report's authors, told Down To Earth.
The study considers environmental and governance conditions in upwind regions, where the moisture for rain originates.
“Water supply really originates beforehand, with moisture evaporated from land or in the ocean traveling in the atmosphere before falling as rain. This upwind moisture is commonly overlooked when assessing water availability,” Fernando Jaramillo, associate professor in physical geography at Stockholm University and one of the authors of the report, said in a statement.
Traditionally, water assessments for lake or river shared between different countries or authorities mainly consider upstream perspective, which includes conditions in the direction upriver from the waterbody.
The upwind perspective considered in the study examines the area where evaporated water is transported before ending up as rain. The area, according to the study, is called a 'precipitationshed' and can cover large areas of the earth’s surface.
The analysis found that some 32,900 cubic kilometres per year of water requirements face very high risk, a near 50 per cent increase, compared to the 20,500 cubic km per year resulting from the more traditional upstream focus.
Evaporation on land contributes around 40 per cent of continental precipitation. This means precipitation over large parts of the Earth’s land surface can be vulnerable to changes in the amount and timing of evaporation entering the atmosphere in upwind areas. While irrigation can increases precipitation in downwind regions, deforestation has the opposite effect, the study highlighted.
Evaporation loss occurring in upwind areas could lead to a loss in downwind precipitation, impacting agriculture, hydropower, water availability in surface and groundwater, aquatic and terrestrial ecosystems and the livelihoods of many urban and rural communities.
In African and Middle Eastern countries, the hazard is mainly related to low governance values, while in Asian countries, it is due to low environmental performance.
Congo is a large basin with low governance and environmental performance. The water requirements of the Congo River Basin are dependent on upwind moisture in neighbouring countries with low environmental performance and governance, such as risks due to potential deforestation and unregulated land use changes.
This, according to the study, implies potential hazards to Congo’s water security.
"It is not possible to ignore the interdependence between countries. In the end, all water is connected, so we should not only mind how we manage our water resources within a region or country but also how our neighboring countries do,” Lan Wang-Erlandsson, researcher at the Stockholm Resilience Centre at Stockholm University and co-author of the study, said in a statement.
The team hopes to evaluate the interconnection between countries through the atmosphere and the surface. In some cases, Jaramillo explained, the water security of downstream countries depends on upstream countries when a basin is shared with them.
“Possibly, upstream countries depend on downstream countries through the atmosphere. This viewpoint could help to strengthen hydro-cooperation between countries and safeguard regional water security,” he added.