“In the next 30 years, it is projected that heavy rainfall events will be increasing … in Asia, by about 20% for sure,” climate scientist Dewi Kirono at Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) told CNN.
Southern Asia is already the wettest area on the continent and one of the wettest regions in the world, receiving an average of at least 1000mm of rainfall a year.
As the rains fall harder, more than 137 million people in India, Bangladesh and China will be put at risk of coastal or inland flooding, more people than in the rest of the Asia-Pacific combined, a study in 2012 found. The majority of flood-related deaths and injuries worldwide since 1950 have been in three countries. According to statistics from Belgium’s Universite Catholique de Louvain’s Emergency Events Database, since 1950, more than 2.2 million people in these countries have been killed by flooding.
The problem centers around three of the great Himalayan rivers of South and East Asia: The Ganges, Brahmaputra and Yangtze. About 500 million people, or 50% of the population in India and Bangladesh, and about 300 million people, or about 25% of the population of China, live within the flood basins of these three rivers. Taken together, the three waterways support an estimated 14% of the world’s total population. When the heavy rains higher up in the flood plains flow into these rivers, water levels rise dramatically — and floodwaters pour into the surrounding cities and towns.
Still, these factors have been here for years. Why is the danger growing now?
“A lot of the urbanization … has happened in a largely unplanned matter.” Abhas Jha, the World Bank sector manager for Transport, Urban and Disaster Risk Management for East Asia and the Pacific, said. As natural drainage, such as open green spaces and wetlands, are covered in cityscapes…, heavy rain has nowhere to go. And the rains are getting heavier.