Muhammad Dikman Maheng earns PhD for research on how urbanization affects temperature, rainfall and flooding in Jakarta

“My PhD research looks at how the reduction of green spaces due to urbanization affects cities,” he explains. “In the coming decades, most of the world’s population will live in urban areas, driving demand for housing, offices, and roads. This leads to a decrease in natural green spaces, which impacts the local hydrological cycle.” Maheng describes how reduced green spaces lower the rates of evapotranspiration and infiltration, resulting in warmer urban areas, known as Urban Heat Islands (UHIs). UHIs can disturb atmospheric circulation and affect rainfall, often triggering extreme weather events leading to urban flooding where the urban drainage conditions are insufficient. These combined hazards create what Maheng calls “multi-hazard events” which can take place in the same location, but at different times.

His findings underscore the importance of maintaining green spaces and adopting green infrastructure, as cities strive to be resilient and adaptive to climate change. This work directly supports global efforts like the United Nations Sustainable Development Goals, in particular SDG 11 for sustainable cities and SDG 13 for climate action.

Maheng recollects the time when he was invited to lecture an MSc module on Water Sensitive Cities. The module focused on the water-city relationship, with no mention of the Urban Heat Island (UHI) effect. He introduced the concept of UHI, which gave students a new insight into urban planning and climate resilience. “Most of the students were new in the topic of urban heat island, and how to use green spaces and green infrastructure to tackle various issues in urban areas including high urban temperature and urban flooding,” he recalls.

Part of his PhD took place during the COVID-19 pandemic, which threw up significant challenges in accessing data. “The most challenging part was collecting data from research partners,” he says. Lockdowns and restrictions on movement meant that many government offices were closed or only open part-time, which delayed the publication of two of his papers just before his defence.

Reflecting on his journey, Maheng would advise his younger self to “start with a simple idea, and then develop it by considering the inter-relationship of the topic with other disciplines. Hence the simple idea will give a significant contribution to the knowledge and can better impact to the real-life.”

Looking ahead, Maheng plans to expand his research to different urban areas, exploring the differences between urban heat islands in coastal and inland cities, and in developing and developed countries. He also hopes to investigate how UHIs influence energy consumption, with regard to net-zero emissions targets. His work offers practical insights for climate adaptation in the world’s rapidly urbanizing areas.