Come to the annual conference of ICLEI Resilient City for solutions on flood and heat wave

Urban resilience is built in nature

According to data of United Nations Human Settlements Programme (UN-HABITAT), up to 60% of major international cities are at risk of wind disasters, floods and tsunamis. By 2050, 70% of the world’s population will live in cities. With development of less resilience, the impact of natural disasters on metropolitan areas is worrisome.

Therefore, the resilient cities conference introduced a new concept: Nature-Based Solution (NbS). A key solution listed in the World Water Development Report in 2018 to cope with challenges faced by the society, mainly by the way of restoration of nature or improving ecosystems. For example, building green roofs, planting greens on walls in metropolitan areas, creating urban food forests, marking out multifunctional artificial wetlands and those by making use of various green and natural facilities to mitigate consequences of urban disasters are all within the scope of NbS.

What is beyond imagination is that the benefits of NbS not only make the environment better, but also consider both social and economic levels. A project funded by the European Commission to promote NbS –NATURVATION– Presented a number of successful cases at the conference. One of which is the Project of “Food for Good” in Utrecht, the Netherlands. The project uses about 0.7 hectare of land in the city, to grow vegetables and fruits to cure the ecological environment and regularly supply to local disadvantaged groups (i.e. elderly, refugees and mobility-impaired persons). In the process, the interaction and participation of local residents have increased, so that vulnerable groups will not go hungry. A single prescription solves environmental, economic and social problems at once.

For prevention of heat injury, technology is the key

In addition to NbS, the conference also invites a private company to introduce an APP software – Extrema – to cope with heat waves. Through the ICT-based solution, this APP lets citizens see in real time the temperature in their area and shows nearby summer shelter spots, so that they can escape from the “heat threat” in the shortest time and in the most efficient way. This APP is said to be the most frequently downloaded software in the past two years. It can detect many European big cities, including Rotterdam, Paris, Milan, Lisbon, Athens and Palma.

In addition, the Research Team of the University of Stuttgart presents another solution, they have prepared a “vulnerability” and “risk” assessment map for the city of Bonn. Through the urban population density map, which overlaps the current and the future density, the forecast of temperature increase in different areas, and elderly residence and poor population distribution areas. The team finds the most vulnerable and risky areas in the city after the temperature rises sharply in 2030, which will help the planning of residential areas and elderly communities later on, or know which areas the city government should give priority to when the extremely deadly heat wave comes again.

Vulnerability and risk assessment map prepared by the University of Stuttgart for Bonn

In retrospect of the construction of domestic urban resilience, “Sponge City” is highly praised by some counties and cities at present is a part of NbS. However, as mentioned above, it is not just as simple as pure disaster prevention function and climate change adaptation, the balanced requirements between the environment, society and economy (Triple Bottom Line) need to be taken into account. Therefore, in addition to using green space to control water, cities in Taiwan might as well think about urban food forests, green roofs, plant-growing walls, or creating a “vulnerability” assessment map that can enhance the city’s disaster prevention system and social and economic welfare.