Climate Change Hazards: Extreme Precipitation and Flooding in Oklahoma's Tribal Nations

Extreme weather hazards are important because they can result in the loss of life, destruction of property, and damage to the environment. It is therefore important to understand how the frequency and intensity of these hazards may change in the future due to climate change. For this study, we address extreme precipitation across Oklahoma, specifically the area which the Citizen Potawatomi Nation, Choctaw Nation of Oklahoma, and Chickasaw Nation encompass. Based on interviews with tribal emergency managers of these three nations, flooding was indicted as a particularly impactful hazard. As a result, this project develops nation-specific projections in heavy precipitation, using various metrics to quantify extremes. High-resolution (~6 km) statistically-downscaled climate model projections, from the Multivariate Adaptive Constructed Analogues (MACA) project were used to assess future changes in heavy precipitation. The results of the future projections show that the average daily precipitation rate does not change in the mid-century (2021-2051) or late-century future (2060-2090); however, heavy precipitation at higher thresholds are likely to increase over these tribal nations in Oklahoma for the same time periods. This was evident by the trends identified in frequencies of 2 inches and 4 inches per day, and 5-day accumulations exceeding 8 inches. Overall, this research will assist tribal emergency mangers in planning for and mitigating potential impacts of floods.