Kentucky is located in the central-eastern US, characterized by moderately large temperature variability and abundant precipitation. Over the past decades, this region did not undergo a significant increase in temperature but witnessed an upward trend in extreme precipitation events. How these changing patterns would evolve and impact crop production in the future has not been well quantified, therefore bringing uncertainties to establishing informed mitigation strategies and sustainable agriculture in Kentucky. In this study, we compiled the projected climate datasets in Kentucky from multiple CMIP5 models under the RCP 2.6 and RCP 8.5 scenarios and analyzed changes in temporal and spatial patterns of extreme dry and wet events from 2010 through 2100 using the Standardized Precipitation Evapotranspiration Index. We then calibrated a process-based agroecosystem model using filed observations and the agricultural production survey. The well-calibrated model was applied to predict the potential effects of future extreme climate events on the production of primary food and cash crops (corn, soybean, and tobacco) in Kentucky.
Results/Conclusions
Our results suggested that extreme dry events would become more frequent and severe through 2100 for the RCP 8.5 pathway (a no-mitigation scenario), while the frequency of extremely wet events would decrease. For the RCP 2.6 pathway (an ambitious mitigation scenario), our frequency analysis showed no statistically significant trends in extreme dry/wet events over the entire study period but an apparent increasing trend after the 2050s. When investigating seasonal and spatial patterns, our results indicated that most extreme dry events would occur in January, June, July, and December. Our model simulation results showed that the projected increasing extreme events would reduce crop production and create more exceptional vulnerabilities for crops, especially under the RCP 8.5 pathway. Our study highlights the importance of the climate transition zone in achieving regional food security. The results will contribute to realistically quantifying local crop production responding to climate change and provide scientific information for building resilience to climate change in Kentucky and possibly other regions.