Characterizing drought risks and implications for water management under climate change

Technical Report

Drought risks arise from the intersection of climate hazards and social vulnerability. To characterize drought risks, we develop and demonstrate a new Combined Drought Risk Index (CDRI). We link a Global Climate Model-driven top-down approach to drought hazard prediction under lower and higher emission scenarios with a bottom-up component that investigates a facet of vulnerability. For the latter, we use stakeholder interviews to investigate how important stakeholders believe that water is for various local uses and measure their cultural worldviews. The CDRI is demonstrated for a study site in south-central Oklahoma, where water availability is highly influenced by drought and management of water resources is contested by local stakeholders. For this region, following the higher emissions scenario leads to more frequent droughts, particularly at higher magnitudes. Stakeholder interviews reveal that people perceive the importance of water differently for various uses. The CDRI combines the drought projections and stakeholder perceptions to show that for water uses where values are diverse, perceived differences are exacerbated in the future, especially under higher emissions. We also investigate why stakeholder perceptions differ by examining cultural worldviews, which can help to diagnose why disagreement may arise over water management. For some water uses, the importance people attribute to water can be partially explained by worldview, pointing to some implications for water management policy. We discuss how the results can be used to reduce potential disagreement among stakeholders and promote sustainable water management, which is particularly important for planning under potentially increasing drought.