For the first time, the team has been able to assign monetary values to the benefits provided by groundwater, showing that the total economic value of this vital asset is approximately $2000 per person globally each year.
Groundwater provides many benefits, including drinking water for approximately half the world's population, essential water for irrigation, supporting wetlands, and contributing to the cooling of cities and landscapes. However, it is often not valued or measured, and is increasingly under pressure.
The researchers say that these new monetary values demonstrate that failing to account for and value this resource will ultimately have a significant economic impact.
Lead researcher, PhD student Eleanor Jewitt from UEA's School of Environmental Sciences, said: "We decided to look at groundwater because, although its importance to society is widely recognized, historically there's been a lack of data to describe the value that people place on groundwater and the benefits that it provides.
"We aimed to fill this gap -- and successfully attributed monetary values to groundwater across a diverse set of ecosystems and geographies."
To calculate the values of groundwater, the team used a choice experiment survey of 10,000 people from 20 countries. The survey asked people a set of multiple choice questions designed to discover how much they would be willing to pay -- through taxes or other payments -- for specific changes in the quality or quantity of groundwater in particular locations.
Co-author Prof Neil Hanley, also from UEA's School of Environmental Sciences, said: "We found that people across all the countries were willing to pay for improvements to the provision of groundwater, across a range of different benefits including improving domestic use, reducing the risk of coastal erosion, and supporting important wildlife habitats.
"We used the responses to derive estimates of people's 'willingness to pay' for changes to groundwater provision, and calculated the value of groundwater across the world. Summing these values across the countries we surveyed suggests the global value of groundwater to be around $18trn per year -- which equates to around $2,000 per person per year.
"This provides an indication of what society could be losing if groundwater stores are not managed sustainably."
He added: "Groundwater is currently one of the most stressed components of the Earth system. It is very vulnerable to pollution and, with increasing populations and water consumption globally, it is likely that the value we found will only increase.
"Our findings highlight that it's vital that we place a value on natural assets like groundwater so we are better placed to manage them and protect them for future generations."
To do this, the team say their findings could inform policy makers, water resource managers and other stakeholders about the value of groundwater and the potential economic costs of groundwater degradation -- ultimately helping to achieve sustainable groundwater management.
The study, published in the journal Nature Sustainability, was conducted as part of the Groundwater and Ecosystems Services (GRoWES) project. The project is a collaboration of 20 institutions, which aims to improve the quantification and economic valuation of groundwater-dependent ecosystem services.
