phys.org - New review of world water resources provides sustainable management strategies
“We have droughts and we have floods. We are trying to manage those extremes and a way to do that is to store water.”
This article highlights a new study, published in Nature Reviews Earth & Environment, which looks at worldwide water management. Surface water and groundwater are interconnected but often managed separately, we must consider them as one resource so that neither gets depleted. This study took data from satellites, climate models, monitoring networks, and many scientific papers to investigate water management strategies and tied in the sustainability component. Globally, human society depends mostly on surface water for potable and industrial water supply. Each year, the world stores about 7,000 – 8,300 cubic kilometres of water in surface reservoirs. Additionally, surface water accounts for 75% of irrigation and 83% in municipal and industry supply annually. And in the US, nearly half of all streamflow comes from groundwater-surface water exchange.
Human activities can affect the surface water-groundwater relationship. By pumping water, streamflow can decline, and irrigation can lead to artificial groundwater recharge. Globally, 30% of annual groundwater pumping originally comes from surface water infiltration. Furthermore, groundwater pumping has reduced the amount of water flow into streams, putting 15-21% of global watersheds are at risk. There are various solutions to manage water, natural and engineered, and getting creative with solutions is important. One author suggests that more water should be stored during wet times so there is a supply for drought. Another aspect to consider is water quality.
“This type of integrated research, linking surface and groundwater, is exactly what is needed to develop lasting solutions to issues such as fresh water use. Too often studies are done in isolation, and well-intended applications have unintended outcomes.”
A figure from the review study illustrating global annual water storage and fluxes. Credit: Nature Reviews Earth & Environment (2023). DOI: 10.1038/s43017-022-00378-6
The Canada1Water project will evaluate climate change impacts on groundwater and surface water sustainability across continental Canada. This will aid policymakers in making decisions surrounding managing this precious resource. This platform will include decision support tools to inform on droughts, floods, carbon sequestration, wildfire risk, permafrost changes, ecosystem services, and surface/groundwater quantity.
“Water quality is one of the next targets in terms of being able to manage water resources. I like that this was incorporated as well.”