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Abstract Irrigation plays a crucial role in agricultural production across the U.S. Great Plains. Meanwhile, it is a key driver of local and regional climate due to its influence on energy and water exchange between land surface and atmosphere. Despite the irrigation-induced evaporative cooling on temperature alone, how irrigation affects summer heat stress – a combination of temperature and humidity can become a concern to public health concern – is not well understood. This study examines the potential impacts of irrigation practices on summer temperature and heat extremes in the Great Plains using a set of sensitivity experiments conducted with the Weather Research & Forecasting (WRF) model for 10 growing seasons. Results show that intensive irrigation lowers the atmospheric temperature, but the increased humidity from enhanced evapotranspiration, especially during the extreme hot and dry summers, can possibly elevate the risks of heat stress in the heavily irrigated area and its surroundings. The response of humid heat extremes to irrigation depends on the heat metrics used in the assessment. For variables like wet-bulb temperature, wet-bulb globe temperature, and equivalent temperature, irrigation leads to significantly intensified humid heat extremes by up to 5°C and increased heatwave frequency by 3 events year-1. In contrast, metrics like the heat index and environmental stress index suggest that irrigation mitigates heat intensity by decreasing the temperature metrics by up to 1°C. Given the importance of irrigation in Great Plains agriculture in a changing climate, these uncertainties underscore the urgent need to connect heat metrics with health outcomes to better address heat mitigation in rural communities.
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Water Smart Cities Increase Irrigation to Provide Cool Refuge in a Climate Crisis
Abstract Water smart cities are increasing their use of irrigation and misting to cope with extreme heat and drought. This is being enabled by widespread use of rainwater tanks, stormwater capture and storage systems, and recycled sewage wastewater to irrigate street trees as well as private and public green spaces. These alternative water resources provide new options for cities to better withstand and function under extreme summer heatwave conditions with little or no impact on drinking water supplies. Small‐scale approaches to evaporatively cool urban animals, vegetation habitat, and people are showing initial success. However, ongoing testing and modeling are needed to understand the impacts of scaling up these interventions and to evaluate their cost‐effectiveness. We describe current innovations in irrigation of Australian cities to help policy development in other countries and cities experiencing similar climates with episodic summer heatwaves.
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- PAR ID:
- 10359980
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Earth's Future
- Volume:
- 9
- Issue:
- 1
- ISSN:
- 2328-4277
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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