Millions of residents have returned to areas along the Yangtze River used for water retention

A leading expert on the Yangtze River is warning of potential danger as China battles flooding along its longest river.

Chen Jin, vice-dean of the Yangtze River Scientific Research Institute, said that people have moved back into some flood retention areas in the Yangtze River Basin after an unprecedented disaster in 1998 drove them out.

It has been a common practice for people living along the river to encircle land with earthen dikes and to plant crops in areas that should be reserved for flood retention.

The change is understandable as there has been no major flooding since that year, Chen said, but there are risks.

The Three Gorges Reservoir and other reservoirs in the upper reaches of the Yangtze have reduced the likelihood that flood retention areas will be needed, but there is still risk of a tragic repeat of history if flooding were to come again, he said.

After the devastating flood in 1998, which killed 1,800, some of the encircled lands were restored, while some were left alone. People were not allowed to live in the areas.

Chen said he observed some of the residents who had reoccupied the encircled lands during an flood control inspection tour in western Hunan province.

Statistics from the Yangtze River Flood Control and Drought Relief Headquarters showed that 6 million people are living on such land in the Yangtze Basin. This year 2.89 million of them were evacuated for safety.

"Every time after experiencing a flood disaster with great loss, people left," Chen said. But after several decades without a disaster, they intruded again. This has been repeated many times in history.

"These encircled lands are what I worry about most. People have forgotten the pain after the wound is healed."

He said the flood retention areas are the last resort in flood control planning and will be used only when floods exceed the capacity of dikes and after reservoirs reach their maximum storage capacity.

"Floods happen once in decades. Moving back to the land is understandable as food security has been a big problem in China. Sometimes, local governments think it's a waste to leave those lands unused," Chen said.

"But after food security is guaranteed, we still have to restore reclaimed lake areas. Only in this way can we live harmoniously with flooding."

"We could use the economic benefits of power generation in the upper reaches to compensate for the cost of restoring lakes in the middle and lower reaches. Once flood retention areas are broadened and floods have enough space to flow harmlessly, the conflict between humans and water will no longer be significant."

houliqiang@chinadaily.com.cn

(China Daily 07/12/2016 page5)