Shanghai will be hurt most by Three Gorges Dam project, researcher says
As Yangtze River levels decline, so will sediment, and seawater will then erode the coastline, a Chinese Academy of Sciences professor predicts
The long-controversial Three Gorges Dam project is expected to bring especially serious environmental harm to the Yangtze River estuary, and Shanghai will bear the worst of it, said a government scientific think tank researcher.
The project is going to reduce the amount of river water and sediment in the Shanghai area, and seawater will encroach on and cause erosion to the coastline, according to Professor Chen Guojie of the Institute of Mountain Hazards and Environment under the Chinese Academy of Sciences.
“For Shanghai, what is good and useful is decreasing, while the harmful and toxic is increasing,” he also said last month at a seminar in Beijing on the environmental impact of the dam project. A transcript of his speech was posted online today by thepaper.cn.
“For example, sediment is a very important resource for Shanghai, which made the land expand by 40 metres each year on average in the past. But it’s no longer the case now,” according to the transcript.
“Because the water became cleaner after mud and sand subsided in the reservoirs in the upper reaches, there would be much less sediment in the estuary,” he explained to the South China Morning Post.
Lower water levels in the river could lead to the intrusion of sea water, which would impact the fish ecology in the area, too, Chen said.
“We should also consider the outcome when encountering several extreme conditions simultaneously in the long term,” he said. “For example, in a dry year, the demand for water for industrial, agricultural and daily use is high in the Yangtze River Delta, plus water is being transferred to the north by the South-to-North Water Diversion Project. Water is reserved at the Three Gorges, and there is a rise in sea level and a high tide …”
He said local governments’ battles for water resources are intensifying since the construction of the project.
Hubei province is trying to transfer Yangtze River water to the Han River; Jiangxi is building a dam on Poyang Lake, China’s biggest freshwater lake; and Hunan is also planning to rebuild reservoirs on Dongting Lake, the second-largest freshwater lake.
“Plus, with the numerous hydropower stations on the upper reaches, a healthy Yangtze River would be impossible in the future,” Chen said.
The Three Gorges is the world’s largest hydropower project. Construction of the project, which has cost more than 248 billion yuan (HK$312 billion), began in December 1994, and authorities are conducting the last round of check-ups as it reaches its completion.