by Chloe Soltis
The majority of the world uses upstream water as its main resource for freshwater. Yet, pollution issues that result primarily from economic development continuously threaten these freshwater sources. Industrialized countries have the financial capital to engineer and build infrastructure such as dams and water treatment facilities to alleviate these issues. Developing countries do not have the means to build the same traditional infrastructure and therefore can struggle with proper water management. Green et al. (2015) realized the need for an integrated water management approach that accounted for different levels of social and economic development and decided to develop the freshwater provisioning index (FPIh). This index measures the amount of upstream freshwater resources available to the human populations living downstream while also taking into account global water source threats.
The Green team first mapped all of the freshwater sources on the planet and calculated the respective populations that they served per grid cell. They evaluated the quality of these sources by analyzing three threat types: gross incident, residual, and adjusted. Gross incident threat accounted for the damage the threat caused before it was fixed. Residual threat examined the damage caused by engineering measures taken to fix original threats. The adjusted threat is essentially the residual threat but is rescaled so that it can be directly measured against the incident threat. The team combined the FPIh grid measurements with these three threat assessments to create percentiles ranging from low (0 – 30th percentile), high (70th – 100th percentile), or moderate (anything between low and high) for threat scores. These rankings allow for the team to see which regions of the world have the most threatened freshwater sources.
The Green team concludes that the incident effect is considered high for 82% of the world’s freshwater resources and the residual effect is globally moderate at 81% with China, India, Africa, Europe, North America, and South America being the most threatened regions. The team’s goal for these data statistics is for developing countries to be able to learn where water restoration efforts are most needed and to work on finding green solutions that are affordable and more environmentally sustainable than costly infrastructure.
Green, P., Vörösmarty, C., Harrison, I., Farrell, T., Sáenz, L., Fekete, B., 2015. Freshwater ecosystem services supporting humans: Pivoting from water crisis to water solutions. Global Environmental Change 34, 108 – 118. http://www.sciencedirect.com/science/article/pii/S0959378015300017.