MSc alumna’s research aims to help flood-proof cities

Mila Avellar Montezuma graduated in April 2023 following studies in Water Science and Engineering with specialization in Sustainable Urban Waters Management and Climate-Resilient Cities. As part of her studies, she conducted research together with the China-Europe Cooperation on Sponge Cities, Deltares, Delft University of Technology and North China University on Water Resources and Electric Power.

“Urbanization typically increases the size and frequency of floods,” said Avellar Montezuma. “So, how can we design for, with and by nature to cope with this type of situation? Assume it will flood and it will be extreme as a design premise. How can we transform the challenges posed by extreme floods into opportunities that not only minimize the risks associated with these events, but also unlock their potential benefits and leverage them for massive adaptation?”

Simulations she created show green corridors meandering through cities – nature-based solutions applied to benefit not only the immediate environment, but also surrounding areas. Such buffer zones are easier to create when planning new urban areas or in existing areas that are less dense. In cities tightly packed with buildings and roads, the challenge is tougher – but not impossible, she said.

“Incorporating extreme floods and droughts as an integrated design requirement is a key lesson  valid not only for China and Europe, including the Netherlands, but also in all places that face similar challenges worldwide,” she said. “In addition to making cities more resilient to floods, this also makes them vibrant places to live. We are co-creating a vital and liveable city – a sensitive urbanism that is full of greenery and full of buffers for floods, food production, droughts and socio-cultural interaction. This builds capacity, and besides decreasing the risks of extreme floods, it provides lots of co-benefits for humans, biodiversity and the territory itself.”

Avellar Montezuma’s findings are highlighted in forthcoming papers and book chapters, but she also strives to have them applied by city planners and policy makers around the world.

Beyond China, Avellar Montezuma has applied these principles and tools to lead collaborations with other hotspot-countries - such as Bangladesh, the United States, Brazil and the Netherlands. Her task is to develop visions and strategies to water challenges such as sea level rise, extreme floods and droughts.

“In an era where nature is over-smarting cities more than ever, it is not only about the design of the world, but also radically about the world of design,” she said. “The highest order of success in design is to achieve ubiquity, to be taken into the culture, to become banal.” 

The sponge city approach, first introduced and widely used in China, involves making cities more absorbent, so that they soak up large volumes of water during floods, and release it later when conditions are drier. Using research by design and modelling, Avellar Montezuma combined sponge-city principles with the Dutch three-point approach, which focuses on prevention, preparedness and response to extreme events at all scales.

Sponge cities, Avellar Montezuma said, are supposed to absorb about 70 percent of annual precipitation. But sometimes, they can’t handle peaks and floods can occur. Architects, engineers and urban planners seek solutions, but often, a solution in one place worsens the problem in another. A wider perspective and systems thinking is needed. This not only avoids moving the problem around, but also makes solutions more effective.

“When measures are isolated, the capacity is typically lower. When connected, then it results in a system, such as an urban buffer, and it tends to become significantly more effective,” Avellar Montezuma said.