Exploring the Potential Impacts of Irrigation on Temperature Extremes in the U.S. Great Plains

Keywords: irrigation, heat stress, climate model
Abstract Type: Poster Abstract

Abstract

Irrigation has been frequently proposed as a climate mitigation strategy due to its agricultural benefits and cooling effect. As irrigation could also increase heat stress through elevating humidity, its adverse impacts on rural communities, however, are significantly overlooked. In this study, we use the Weather Research & Forecasting (WRF) model to investigate the impacts of growing-season irrigation practice on temperature and wet-bulb temperature, and its implication in humid heatwave development. Based on irrigation experiments for five wet years and five dry years, we find that irrigation leads to decreased air temperature but significantly enhances wet-bulb temperature. Even with the same amount of irrigation, its temperature effects are more profound during the dry years compared to the wet years. Process-focused analysis reveals certain contributions of irrigation to the development or intensification of selected humid heatwave events in the Great Plains. Reducing irrigation amount and using drip irrigation may alleviate the risk of irrigation-induced humid heatwaves. This study highlights the role of land-atmosphere interactions in heat extremes, and suggests the trade-off of irrigation in climate mitigation.