Floods in megacities: impacts of urban growth, sustainable infrastructure and climate change

在全球范围内，洪水是最具破坏性的自然灾害之一，影响许多地区，每年造成数千人伤亡和数十亿美元的损失。由于城市化、基础设施老化以及极端天气事件的频率和强度不断增加，所有城市都变得越来越容易受到洪水的影响。特别是特大城市（人口超过1000万的城市）面临更大的风险——这些地区的城市增长速度快于其他地区，大中心受影响的人口和经济资产数量也远高于其他地区。因此，必须制定更好的城市防洪方法，包括改进洪水预报方法和有效的防洪基础设施。

Globally floods are one of the most devastating natural disasters, impacting numerous regions, responsible for thousands of casualties and billions of dollars in losses annually. All cities are becoming more vulnerable to flooding due to urbanisation, ageing infrastructure, and the increasing frequency and intensity of extreme weather events. In particular, megacities (cities with a population greater than 10 million) face even greater risks – the urban growth in these areas is faster than other regions and the number of people and economic assets affected in large centres is also far higher than anywhere else. It is therefore essential to develop better urban flood protection methods, including improved flood forecasting methods and effective flood mitigation infrastructure.