A study examining nearly 1,500 river sites in the US between 1980 and 2022 has shown that river heatwaves are happening up to four times faster than air heatwaves and lasting nearly twice as long. “Agriculture has been mitigating riverine heatwaves via cooler air and water during irrigation, as indicated by declining trends in the frequency, duration and intensity of riverine heatwaves in crop-cultivated areas,” said Sadayappan. “On the other hand, dams have been accelerating trends in riverine heatwaves. The researchers say their findings can now inform strategies to mitigate river heat waves, a phenomenon that, until now, has been relatively poorly studied and reported. “This information can provide warning signals and support adaptive management during riverine heatwaves,” Sadayappan concluded.