Criticality of Water: Aligning Water and Mineral Resources Assessment.

The concept of criticality has been used to assess whether a resource may become a limiting factor to economic activities. It has been primarily applied to nonrenewable resources, in particular to metals. However, renewable resources such as water may also be overused and become a limiting factor. In this paper, we therefore developed a water criticality method that allows for a new, user-oriented assessment of water availability and accessibility. Comparability of criticality across resources is desirable, which is why the presented adaptation of the criticality approach to water is based on a metal criticality method, whose basic structure is maintained. With respect to the necessary adaptations to the water context, a transparent water criticality framework is proposed that may pave the way for future integrated criticality assessment of metals, water, and other resources. Water criticality scores were calculated for 159 countries subdivided into 512 geographic units for the year 2000. Results allow for a detailed analysis of criticality profiles, revealing locally specific characteristics of water criticality. This is useful for the screening of sites and their related water criticality, for indication of water related problems and possible mitigation options and water policies, and for future water scenario analysis.