Entire Asia Hit, but China Has the Mother of All Floods

Floods have hit multiple countries — China, India, Bangladesh, Nepal, Japan, South Korea, and Indonesia, to name a few — this month. However, the scale and intensity have been massive this year, especially in China, India and Bangladesh.

China is seeing one of the worst floods in decades, with the Yangtze River rising to record heights. Millions of people live in proximity to the river, which runs 6,300 km west to east through 11 provinces. According to figures from China’s Ministry of Water Resources, between 1950 and 2018, floods killed more than 2,80,000 people, destroyed over 120 million homes, and damaged more than 9.6 million hectares of crops. The economic cost of floods between 1990 and 2018 was more than 4.37 trillion yuan (US$ 623.6 billion).

Liu Junyan, a climate and energy campaigner with Greenpeace East Asia, stated that to cope with the floods, “the only way is to modify urban planning to better estimate climate risks in the long term”. While this year's floods is comparable to the one in 1998, there have been 15 percent lesser economic loss this time around so far, and 1/10th of the damage to houses due to better rescue and recuperation methods, according to reports. About 1.8 million people have been evacuated.

The floods in China are being seen as a natural disaster, especially when compared to the situation in India, which sees severe flooding more often than not. This situation is believed to have resulted from warmer-than-usual sea temperatures around the Indian Ocean. Dykes have overflowed during previous events, such as the 1931 Central China floods, which were considered one of the deadliest natural disasters of the 20th century. More than 1,40,000 people drowned with at least 3.7 million dying over the following nine months.

THE THREE GORGES DAM

China employs a large number of people and processes in the monsoons to monitor the lakes and rivers. Yet this time, there is concern over the Three Gorges Dam, the world’s largest hydroelectric dam. There were reports of its external structures being displaced, along with seepage into the main outlet walls, yet the situation is said to be under control.

The Three Gorges Dam is a gravity dam, designed to hold back water by using the weight of its material alone. It is designed such that each section of the dam is stable and independent of any other section. The current situation is the first major test that the Three Gorges Dam has been put through, and it is safe to say that the Chinese government is monitoring the situation closely, hoping that the dam will hold up.

HYDROLOGICAL CHALLENGES IN FLOOD CONTROL

However, there are hazards that are unique to the dam. One is sedimentation projections which have been rising. At the current water levels, 80 percent of the land in the area experiences erosion and deposits nearly 40 million tonnes of sediment into the Yangtze annually. Therefore downstream, riverbanks become more vulnerable to flooding, causing biological damage.

Critics of the dam, however, say that it was not made to handle and control flooding, and was built solely for economic purposes. Fan Xiao, a Chinese geologist, said to Reuters that the storage at Three Gorges amounts to less than 9 percent of floodwater. “It can only partially and temporarily intercept the upstream floods, and is powerless to help with floods caused by heavy rainfall in the middle and lower reaches of the Yangtze River,” he said.

The blame for the floods is not due to simply the dam and climate change. Along the course of the Yangtze River, there are thousands of smaller dams that help keep the river in check. Yet reports state that some of the older dams on the river have not been maintained well, and new projects are taken up instead of maintaining the older ones. More than 80,000 reservoirs in China, of which about 50,000 are in the Yangtze River basin, do not store water up to their capacity as they are subject to leakage.

Repairing older flood-control measures such as dykes and reservoirs is also of importance in flood control. Ecological conservation also plays a role inmitigating floods. Wetlands that earlier served as natural flood barriers have been destroyed in the name of urban development since the 1950s. Currently, the water level of 433 rivers is above the flood control line, with 33 of them reaching record highs.

There is a need to move away from traditional watershed management towards a 360-degree approach that embraces all aspects of the area, including protection of public goods, ecosystems, biodiversity conservation, relief measures, and climate change.

FLOODS IN INDIA

India’s monsoon has always been fickle and has precipitated floods, especially since the principal river systems are fed by the Himalayan ranges. Yet experts say that a combination of global warming, faster glacier melting, conversion of forests to farmland, unplanned urban growth, and environmental degradation have increased flood risk in India. At present, Assam and Bihar face the brunt of it this year, with floods continuing throughout July.

The destruction of mountains and hills and the development of cities on floodplains and marshes exacerbate the risk. India saw up to 90 floods in the 10-year period from 2006 to 2015, an increase from 67 in the 10 years between 1996 to 2005, according to the UN Office for Disaster Risk Reduction. More needs to be done to reduce risk in the area, with a focus on permanent rehabilitation methods instead of temporary attempts at relief. India, and most of Asia, now see more heavy rainfall and drastic dry spells, showing how the vast and varied swings between climates due to global warming is harming the land.