Frontiers of household water insecurity metrics: severity, adaptation and resilience.

The measurement of household-level and individual-level water insecurity has accelerated over the past 5 years through innovation and dissemination of new survey-based experiential psychometric scales modelled after food insecurity scales. These measures offer needed insight into the relative frequency of various dimensions of water problems experienced by households or individuals. But they currently tell us nothing about the severity of these experiences, mitigating behaviours (ie, adaptation) or the effectiveness of water-related behaviours (ie, resilience). Given the magnitude of the global challenge to provide water security for all, we propose a low-cost, theoretically grounded modification to common water insecurity metrics in order to capture information about severity, adaptation and resilience. We also discuss ongoing challenges in cost-effective measurement related to multidimensionality, water affordability and perception of water quality for maximising the impact and sustainability of water supply interventions. The next generation of water insecurity metrics promises better monitoring and evaluation tools-particularly in the context of rapid global environmental change-once scale reliability across diverse contexts is better characterised.