“We set up at Encanto Park in February 2019 and all of our instruments were operational by the next month,” Kindler said. “For a year, we conducted weekly or biweekly visits to the sites for data collection and station maintenance. It has been a great experience working on this research project, since it has allowed us to learn more about water and energy fluxes at an urban golf course.”

Their notable findings were twofold. First, the oasis effect led to unexpectedly high evaporative losses during the night. Second, the oasis effect was related to the evaporation of soil water and irrigation water, and not to the activity of plants and grasses in the park. 

“Because of the oasis effect, when we irrigate our urban parks at night, we lose vast amounts of water and we see increased carbon dioxide emissions, which could lead to higher global warming potential,” Vivoni said. “This has important implications for water conservation and greenhouse gas emission management in desert cities such as Phoenix.”

While additional studies are needed to determine when during the day it would be preferable to irrigate, making this management change would decrease evaporative loss and the carbon dioxide emissions — which contribute to global warming — during hot, dry, windy days.

It also remains to be determined how widespread this effect is within Phoenix. Given the large number of parks and golf courses, however, it is anticipated that the results of this study will yield important regional consequences to be considered by state, county and city agencies.

Karin Valentine

Media Relations & Marketing manager, School of Earth and Space Exploration

480-965-9345