Water, warming and a world at risk

• A UC Irvine professor of civil and environmental engineering, Amir AghaKouchak was named a 2026 Frontiers Planet Prize national champion.
• The sole winner from the U.S., he's in the running for one of three $1 million prizes to be awarded later this year.
• AghaKouchak credits his postdocs, students, collaborators and colleagues at the campus's Center for Hydrometeorology and Remote Sensing along with UC Irvine's culture of interdisciplinary collaboration.

In the six decades since it was founded, UC Irvine has garnered a reputation as an engine of solutions-oriented research and innovation. Having been on campus for a quarter of those 60 years, Amir AghaKouchak, Chancellor's Professor of civil and environmental engineering and director of the Center for Hydrometeorology and Remote Sensing, has helped increase the institution's renown with his lab group's research on the effects of water resources and climate extremes on the environment and infrastructure systems.

On the occasion of Earth Day 2026, AghaKouchak is being recognized as a Frontiers Planet Prize national champion. The only U.S. representative, he joins an international group of 25 scientists who are being honored for their work in coming up with real-world answers to the planet's climate crisis. They are finalists in the running for one of three $1 million awards to further their research. Winners will be announced later this year.

"This recognition reflects the collective work of many people, including students, postdocs and collaborators, with whom I've had the honor of working," AghaKouchak says. "Together, we study climate extremes and develop datasets and tools to better anticipate risk, protect water systems and infrastructure, and support timely action. We cannot prevent hazards from occurring, but through better science, we can help prevent them from becoming human disasters."

AghaKouchak has come to be known for his studies of compound hazards, such as droughts and heat waves striking at the same time or riverine and coastal flooding happening in tandem. But this path was not apparent to him in his early days as an academic researcher. Born and raised in Iran, AghaKouchak studied at Tehran's K.N. Toosi University of Technology, initially drawn to structural engineering and construction management. Water was nowhere on his radar.

"I didn't know anything about water or climate at the time," he recalls. "After an undergraduate research experience with a glaciologist, slowly and over time, I got more and more interested in water and climate issues. Before I knew it, I'd earned a master's and a Ph.D. in this area."

AghaKouchak's doctoral work focused on the narrow but technically demanding field of radar hydrology, specifically, how to measure uncertainty in radar-based rainfall estimates. A postdoctoral stint then opened his eyes to satellite remote sensing, and when he joined the UC Irvine faculty 15 years ago, his focus shifted again, this time toward hazards such as drought, flood and wildfire - and their impacts.

What started as an effort to combine different drought indicators, rainfall, soil moisture and evapotranspiration into a single, more useful picture eventually led AghaKouchak to a realization that would define his career: Hazards are rarely isolated.

"It occurred to me that this is really important for different types of hazards," he explains. "Droughts and heat waves often reinforce one another and frequently occur together. In coastal areas, multiple flood drivers - including river flooding, heavy rainfall and ocean flooding - can interact and amplify impacts. Likewise, drought and heat can create conditions that greatly increase the likelihood of wildfires."

That insight gave rise to a body of research on what scientists call "compound events," combinations of climate, and even nonclimatic, extremes that are far more destructive together than any single event would be alone. AghaKouchak's first paper on the subject, published in 2013, examined the simultaneous occurrence of droughts and heat waves. It was the opening chapter of what has since become a much larger story.

The leadership team of UC Irvine's Center for Hydrometeorology and Remote Sensing includes (from left) Phu Nguyen, associate adjunct professor of civil and environmental engineering; Kuo-Lin Hsu, professor of civil and environmental engineering; Amir AghaKouchak, Chancellor's Professor of civil and environmental engineering; and CHRS founder and former director Soroosh Sorooshian, the Henry Samueli Endowed Chair in Engineering. Steve Zylius / UC Irvine

Lakes in crisis

The research that caught the eye of the Frontiers Planet Prize committee was a sweeping global study published in April 2025 in the journal Communications Earth & Environment. AghaKouchak and his colleagues Xing Cheng, Shuo Wang and Jianli Chen - all of Hong Kong Polytechnic University - analyzed the world's largest lakes and found a sobering trend: More than half had seen significant reductions in water storage over the past 30 years. The consequences affect roughly 25 percent of the world's population.

The findings matter because lakes and reservoirs are not just scenic backdrops; they are the infrastructure of human survival, supplying drinking water, supporting agriculture, sustaining ecosystems and buffering communities from the worst effects of drought.

AghaKouchak has long argued that looking at reservoir levels is one of the most practical ways to assess drought risk and developed the first socioeconomic drought indicator a decade ago based on California reservoir data. Unlike rainfall data, which tells you what fell from the sky, reservoir storage tells you what is actually available to use. "You may have years with average or even below-average rain but full reservoirs because you had a wet year before," AghaKouchak says. "But if you have below-average reservoirs going into a drought, it'll be a very bad year."

The study calls for high-resolution monitoring of water bodies worldwide, smarter adaptive water management and better planning tools for communities facing extreme dry conditions. It is, in essence, a road map for preventing a global water crisis from catching the world off guard.

Amir AghaKouchak credits his team of fellow faculty, postdoctoral scholars, and graduate and undergraduate students for the groundbreaking work in climate science and civil and environmental engineering that has resulted in him being recognized as a 2026 Frontiers Planet Prize national champion. Steve Zylius / UC Irvine

Building tools that are used by millions

Over the years, AghaKouchak and his colleagues at the Center for Hydrometeorology and Remote Sensing - including its founder and former director, Soroosh Sorooshian, Distinguished Professor of civil and environmental engineering, as well as Henry Samueli Endowed Chair in Engineering; Kuo-Lin Hsu, professor of civil and environmental engineering; and Phu Nguyen, associate adjunct professor of civil and environmental engineering and CHRS associate director - together with their students and postdocs, have developed operational tools that people around the world rely on for rainfall analysis, drought monitoring and prediction, and water resources modeling.

At the center of that effort are a widely used global rainfall data record, a near-real-time rainfall monitoring system, and a global drought monitoring and prediction system - all created and maintained at UC Irvine. Built on a precipitation dataset with more than 45 years of historical data, one of the most comprehensive and near-real-time rainfall records in existence, the rainfall monitoring system uses artificial intelligence to forecast drought conditions month by month, rolling forward in time like a slow-motion weather report for the world's water supply.

The usage numbers are staggering: UC Irvine's CHRS data platform annually draws 1.8 million visitors globally, and people from more than 200 countries download over 160 terabytes of data every year. Developers and researchers everywhere can download the data directly or plug into the university's data through an open programming interface, embedding it into their own systems and websites.

"A lot of people around the world come to our UC Irvine website to get information about rainfall, extreme storms and drought conditions," AghaKouchak notes. "This rainfall monitoring system is one of several tools we have developed over the years, with the help of students and postdocs, to improve the measurement, monitoring and understanding of freshwater availability."

The work does not stop at drought. His group also runs projects on flood modeling, rain over burned areas, and wildfire monitoring and prediction - hazards that, as AghaKouchak would be the first to point out, are increasingly compounding one another.

A campus built for collaboration

Review AghaKouchak's list of co-authors and collaborators, and you get a picture of a scientist who refuses to stay in an established lane.

His work touches colleagues in air quality and Earth system science, urban planning and public policy, public health, and even psychology. One ongoing project involving Roxane Cohen Silver, UC Irvine's vice provost for institutional research, assessment and planning and also a professor of psychological science, and E. Alison Holman, professor of nursing, examines the mental health impacts of wildfires. Political scientists, statisticians, computer scientists and electrical engineers have all found their way into AghaKouchak's research orbit.

"There's a lot of collaboration going on across UC Irvine, and that's what makes it very exciting to be here," he says. "The campus rewards collaboration, and I've benefited from that."

That team spirit - which also spans continents - traces back, in part, to Sorooshian, who first brought AghaKouchak to campus as a postdoctoral scholar. Later, the early-career researcher received a faculty position in the same department, and the two have remained close ever since.

"I've had the privilege of following Amir's career since his early days as a postdoctoral researcher in my group at CHRS in 2010," Sorooshian says. "His rise to Chancellor's Professor at UC Irvine and to becoming a nationally and globally recognized hydrometeorologist and climatologist has been truly remarkable. He combines outstanding scientific insight with humility, creativity and a visionary approach to research. Equally impressive is his commitment to mentoring and his generosity as a colleague."

The Frontiers Planet Prize is more than a trophy. It comes with the expectation that the work being rewarded will move the needle on real-world decisions. AghaKouchak contributed to a Frontiers Policy Labs report released alongside this year's national champion announcements and titled "From Science to Policy: Planetary Solutions in Action." The document makes a pointed argument: The science already exists to address many of the world's most pressing water, environment and climate challenges. The question is why governments and institutions are so slow to act on it.

It's a frustration AghaKouchak knows well. For years, he has advocated practical steps for monitoring and predicting hazards and their impacts on water resources, agriculture and infrastructure systems like levees that were never designed with today's climate extremes in mind.

"We cannot prevent hazards from occurring," he says, "but through better science we can help prevent them from becoming human disasters."

UC Irvine's executive vice chancellor and provost, Hal Stern, says: "Professor AghaKouchak's work has been invaluable to both the global climate science community and government agencies who are looking for guidance on how to build resiliency in the face of challenging climate conditions. We are proud to have him as a member of the UC Irvine environmental research community."