Aerial view of Xinzheng, a sponge city in China. Image by Windmemories, CC BY-SA 4.0 via Wikimedia Commons

Yu Kongjian (俞孔坚), 62, the Chinese landscape architect who pioneered the concept of “sponge cities,” died in a plane crash in the Pantanal region, the largest tropical wetland in the world, in Brazil, on September 23, 2025. Three other people also died during the accident: pilot Marcelo Pereira de Barros, and filmmakers Luiz Fernando Feres da Cunha Ferraz and Rubens Crispim Jr., who were both working with Yu to create a documentary about sponge cities. The cause of the crash is under investigation.

Ferraz’s work focused on nonfiction productions, including a series about the 2016 plane crash involving the Brazilian football team, Chapecoense. Crispim Jr. worked on projects such as a documentary about Brazilian architect Vilanova Artigas and another about the first women’s football national team in Brazil.

Brazilian president, Luiz Inácio Lula da Silva, posted condolences on his X account and highlighted Yu's work:

Foi com tristeza e consternação que recebi a notícia do desastre aéreo ocorrido no Pantanal no início da noite desta terça-feira, 23. A tragédia, infelizmente, custou as vidas do piloto Marcelo Pereira de Barros, dos documentaristas Luiz Fernando Feres da Cunha Ferraz e Rubens…

— Lula (@LulaOficial) September 24, 2025

It was with sadness and consternation that I received the news about the aircraft disaster that happened in the Pantanal regional, early Tuesday night, the 23rd. The tragedy, unfortunately, took the lives of the pilot Marcelo Pereira de Barros, documentarians Luiz Fernando Feres da Cunha Ferraz and Rubens Crispim Jr., and the Chinese architect Kongjian Yu.

In times of climate change, Kongjian Yu became a world reference for sponge cities, which unite life quality and environment protection: something we want — and need — for the future. To all the victims’ friends, family and coworkers, I leave my deepest sorrows.

Yu’s legacy

Tianjin Qiaoyuan Park is one of the early sponge city projects. Image via Wikimedia Commons by Mydogistiaotiaohu (CC BY-SA 4.0).

Yu was in Brazil to work on a documentary, but he had also recently attended the São Paulo International Architecture Biennale, which was themed “EXTREMES — Architectures for an overheated planet.” Raquel Schenkman, the Institute of Brazilian Architects’ president, responsible for the Biennale’s organization, told G1 Yu was “someone on the frontline of transformations in big urban centers facing climate change.”

On its website, the Biennale published a note saying that, as the “creator of the theory of sponge cities, Yu Kongjian left a monumental legacy, also urgent to face climate crisis in cities,” and that his work, based on ecosystemic principles, “showed in a practical and poetic way how the landscape can be a vital infrastructure to urban resilience, integrating man to nature in a sustainable way.”

Sponge cities concept

Yu’s main legacy is designing and implementing projects based on his sponge cities theory. A professor at Peking University, his “sponge city” concept became a top national priority in China in 2013, following the massive floods in the Beijing region in 2012, which left 79 people dead and tens of thousands displaced. He also founded Turenscape, one of the main landscape architecture firms in the world, based in China.

Yu cautioned against overly “grey” cities that rely too much on concrete and asphalt, which disrupt natural water pathways and prevent the ground from absorbing water. While conventional water management focuses on draining water through engineered drainage infrastructure, such as pipes and water channels, sponge cities rely on techniques such as green roofs, rainwater storage and infiltration systems, sunken green spaces, permeable pavement, bioretention ponds, wetland revitalization, restoring natural waterflow pathways, and more.

“Floods are not enemies,” Yu explained in an interview with WeForum. “We can make friends with floods. We can make friends with water.”

Yu’s approach to urban planning has been successfully implemented in dozens of cities in China, particularly after Chinese President Xi Jinping established his thoughts on ecological civilization in 2018. 

In the past decade, his natural landscape approach is becoming an important tool in city planning and water management around the world.

In Southeast Asia, where recurring extreme weather events routinely cause massive floods that displace hundreds of thousands, many city planners are looking to sponge cities as a potential solution for unprecedented levels of rainfall.

So far, the concept has mostly been implemented on a small scale in individual neighborhoods, streets, or areas, meaning its flood mitigation impacts are often limited to the local level, rather than city- or nationwide.

On X, Zhongshan city's tourism promotion outlet, commemorates Yu's death by highlighting one of his landscape projects in the southern Chinese city:

巴西当地时间9月23日，#北京大学 建筑与景观设计学院 #俞孔坚 教授不幸遭遇坠机身亡，终年62岁。俞孔坚教授曾获多个世界级设计奖，包括Oberlander Prize、John Cobb Common Good Award等，而 #广东 #中山 #岐江公园 ，是他的代表作之一。中山岐江公园是由造船厂旧址改建的主题 #公园… pic.twitter.com/s8gejJDNSC

— Amazing Zhongshan (@AmzZhongshan) September 25, 2025

On September 23 (Brazilian time), Professor Yu Kongjian from the College of Architecture and Landscape Architecture at #Peking University, tragically passed away in a plane crash at the age of 62. Professor Yu had won numerous world-class #design awards, including the Oberlander Prize and the John Cobb Common Good Award. Among his representative works is the #QijiangPark in #Zhongshan, #Guangdong . This #park, transformed from the site of a former shipyard, opened in 2001 and quickly gained global attention, winning several domestic and international design awards. In designing and building the park, Professor Yu and his team preserved the original industrial relics, such as shipyard machinery, docks, and other structures, and repurposed them with new functions. [original English version from @Amzhongshan]

Yu himself acknowledged that scaling up the pilot projects in Chinese cities was challenging. One of his sponge city projects in Zhengzhou faced backlash after a severe flood in 2021, which claimed 12 lives in the city, prompting many to express doubts about the practicality of his idea. Moreover, as China's coastal regions are highly industrialized, they demand cross-departmental collaboration, strong political will, and extensive administrative coordination to restore concrete riverbanks and seawalls to wetlands. 

In an interview with Brazilian news outlet G1, Yu said that on a scale of 1 to 10, his optimism regarding the world’s chances of reversing climate change ranked 4. He also mentioned water scarcity — one of the challenges his projects aimed to address — as the primary issue humanity will face over the next 25 years.

A journalist living in China, Isabela Shi, shared Yu Kongjian’s last update on a Chinese social media platform:

🕯️No último vídeo que o arquiteto chinês Yu Kongjian divulgou na rede social chinesa, ele estava mostrando a viagem a Pantanal com equipa brasileira que tenta refletir sobre Planeta Esponja através de encolhimento de zonas húmidas.

“Wonderful, amazing”, encantou ele pro Brasil. pic.twitter.com/fKn5ZKgIwe

— Isabela Shi🇨🇳🇧🇷 (@ShiIsabela) September 25, 2025

In the last video Chinese architect Yu Kongjian posted on a Chinese social media, he was showing his trip to the Pantanal with the Brazilian team that tried to reflect on a Sponge Planet through the shrinking of humid zones.

“Wonderful, amazing,” he said enchanted by Brazil.