Ho Chi Minh City and other Asia's coastal megacities will suffer more frequent and severe flooding affecting millions of people, if current climate change trends continue, a new report says.
Major flooding could cost billions of dollars in infrastructure damage, hurting the economy. The hardest hit are likely to be urban poor populations, says the report titled Climate Risks and Adaptation in Asian Coastal Megacities.
The report was released Friday at the Asia Pacific Climate Change Adaptation Forum in Bangkok after two years of study commissioned by the Asian Development Bank (ADB), the Japan International Cooperation Agency (JICA) and the World Bank.
It examines the impact of climate change on Bangkok, HCMC and Manila, under a range of scenarios until 2050, concluding that the three cities need to take "targeted, city-specific and cutting edge approaches to meet these challenges," an ADB press release says.
The cities have populations close to or over 10 million and are economic centers of their countries and the region.
Yet they are facing increased risks of climate change such as rising sea levels and an increased frequency in extreme weather conditions.
Around 26 percent of the HCMC population is currently affected by extreme storm events but the number could climb to more than 60 percent by 2050, the report says.
It notes that the cities have already taken measures against flooding but need to do much more.
It requires sound urban environmental management to prevent factors contributing to urban flooding, such as land sinking due to groundwater pumping, dumping of solid waste into city waterways, clogged drainage systems, and deforestation in the upper watershed areas.
In the case of HCMC, the report says Vietnam's government has expressed interest in a climate change adaptation plan for the city that can provide an overall framework for adaptation measures within relevant sectors, such as management of mangroves and rehabilitation of urban wetlands.
In Manila, a major flood could cause damage totaling almost a quarter of the metropolitan area's GDP, the report estimates. The main threats to Manila are extreme rainfall, sea level rise, as well as more powerful typhoons.
In Bangkok, flooding is caused by land subsidence and increased rainfall in the large watershed that drains through the city.