Edward Ng on His New Book, 'The Urban Climatic Map'

Edward Ng, co-editor of The Urban Climatic Map, tells us the story behind his new book.

When I had nothing to do in the University I took my students out to remote villages in rural China and help the villagers building schools, bridges, toilets, community centres and playgrounds. In the summer, the days were long and hot, and we suffered the scoffing sun. But from time to time, we felt the breezes from the lake. When the sun was unendurable, we took refuge under the village’s ancestral trees. They planted these trees at the crossroads and near their temple in public squares. Villagers chatted and slept under them. At night, the air turned cool very quickly and almost immediately after the sun was set. It was then enjoyable to sit in the open in the early evening and enjoyed the clear sky and bright stars. After a week or so lived close to the Mother Nature, we reluctantly needed to return to urban Hong Kong.

Hong Kong is one of the world’s highest density urban cities. With over 7 million people living in an urban area of under 200 square kilometres, the urban population density is over 65,000 people per square kilometre. In comparison, London boosts 14,000 and New York is 4,500 [Demographia:2015]. What it means is that in Hong Kong one sees grasslands replaced by asphalt roads and trees replaced by concrete towers. Instead of having insects and animals, we have people and cars. The loss of the land’s ability to convert sensible heat into latent heat, the input of anthropogenic energy and the unavailability of the cool wind entering the city means that the urban core of Hong Kong suffers high urban heat island (UHI) intensity. This impacts human health, especially during the hot and humid summer evenings. It is not for nothing that Mr C Y Lam, the then Director of Hong Kong Observatory, addressed a group of planners and architects during the “Urban Climate + Urban Greenery” conference on 2 Dec 2006 in the following notes:

This city is heading towards a hot, stuffy state of atmosphere. In future summers, the old and the weak living in their tiny rooms in the urban areas will have to face the increasing number of hot nights with no air-conditioning, little wind and the dampness arising from little sun and little evaporation. They also have to fear the attack of more germs than used to be since their natural enemies, viz. fresh air and sunshine, have been reduced in strength. Unfortunately the underprivileged have to look forward to even more tall buildings along the shore or even right at the heart of the urban areas to block the little wind and sunshine left.

The suffering is not unique in Hong Kong. Many mega cities (cities with more than 10 million inhabitants) are located in the Tropics and Sub-tropics. Jakarta, Mumbai, Karachi, Mexico City, Sao Paulo are some examples. Unlike rural villages, human congregation in urban areas changes the energy balance between land and the atmosphere. Human activities and the artificiality create cities with their own unique urban climate. Planning and designing our cities more appropriately to mitigate the ill-effects of UHI and to improve human living is increasingly an important consideration of policy makers, professionals, planners and architects. The key question is: how can we facilitate them? What tool and information they need? And what magnitude of action is needed for the desired benefits? As an architect myself, I have been pondering these questions.

In 2004, I attended the Passive Low Energy Architecture (PLEA) conference in Eindhoven and met Professor Lutz Katzschner of Kassel University. He presented a paper on Urban Climatic Map. I immediately realised the potentials and possibilities of the methodology. The idea is simple. The scientific knowledge of meteorology and urban climatology is represented using maps and the information contained is simplified to allow planners their easy reading and application. After all, planners use maps every day for their work. Maps are their tools.

I took the idea back to Hong Kong and introduced it to our planners. We worked on it for the next 6 years and produced the Hong Kong Urban Climatic Map for Planning in 2012.

I had come to note that we were not alone. City planners and urban climatologists in Germany, Japan, Singapore, and so on were doing something similar. I realised that it would be useful to collect, collate and present the efforts around the world in a single volume; hence, the birth of an idea of the book “The Urban Climatic Map – a methodology for sustainable urban planning”.

The book was introduced by Gerald Mills, then the president of International Association of Urban Climate (IAUC). This was followed by a number of essays on the historical development and the methodology of urban climatic map. This part of the book set the scene for the subsequent case studies.

The 3 following parts arranged by the sizes and scales of the cities contain case studies of more than 20 cities. From the more established system in Stuttgart of Germany to the newer attempt in Singapore, the case studies illustrate how different groups of scientists and city planners have worked together to develop urban climatic maps suitable for their respective cities.

The book is concluded with 7 essays on the future. New technology, new insights and new needs are elaborated and hypothesized. The message is clear. We are only in the beginning of what needs to be done. The adventure is on-going.

I would like to end my blog by telling a story between me and my son. A few years ago my son (aged 6) asked me, “Daddy, when you go and see God, what you are going to leave me”. An innocent question I hope! I replied then, “I hope to leave you a better world for you to continue living”. I could see that he did not quite understand. Or he did and was not satisfied. If he (aged 22) were to ask me the same question today, I would tell him “I will leave you a book to read.” 

  • The Urban Climatic Map

    A Methodology for Sustainable Urban Planning

    Edited by Edward Ng, Chao Ren

    Rapid urbanization, higher density and more compact cities have brought about a new science of urban climatology. An understanding of the mapping of this phenomenon is crucial for urban planners. The book brings together experts in the field of Urban Climatic Mapping to provide the state of the art…

    Hardback – 2015-09-16
    Routledge