Problems
Poyang Lake is China’s largest freshwater lake in the southeastern province of Jiangxi. It is a vital water source for agriculture, industry, and wildlife and a major stopover for migrating birds. Poyang Lake located in Jiujiang, is the largest freshwater lake in China. The lake is fed by the Gan, Xin, and Xiu rivers, which connect to the Yangtze through a channel. Between the winter and summer seasons, Poyang Lake, in China’s Jiangxi Province, routinely fluctuates in size. In winter, water levels on the lake are usually low. Then, summer rains cause the country’s largest freshwater lake to swell as water flows from the Yangtze River. However, the lake has been shrinking dramatically in recent years due to natural and human factors. The lake has not swelled in the summer of 2022. A prolonged heat wave and drought across much of the Yangtze River Basin has dried the lake early and pushed water levels to lows not seen in decades.
Causes of drying up
The leading cause of the drying up of Poyang Lake is the severe drought that has affected the Yangtze River basin, which feeds the lake. According to China’s Ministry of Water Resources, the summer rainfall in the Yangtze River basin in 2022 was the lowest since records began in 19611. This resulted in an unprecedented drop in the water level of the Yangtze River and its tributaries, including Poyang Lake. The lake officially entered its dry season on August 6, 2022, earlier than ever since 19512. By then, the lake had shrunk to 25% of its usual size. Another cause of the drying up of Poyang Lake is the construction of dams and reservoirs along the Yangtze River and its tributaries. The most notable is the Three Gorges Dam, the world’s largest hydroelectric power station. The dam has altered the natural flow and sedimentation of the river, affecting its downstream ecosystems. Some studies have suggested that the dam has reduced the water inflow to Poyang Lake by up to 60%. The barrier also affects the seasonal variation of the lake’s water level, which is crucial for maintaining its ecological functions. A third cause of the drying up of Poyang Lake is the increasing water demand from human activities. The population and economic development in the region have increased the pressure on water resources. Agriculture, industry, and domestic use consume large amounts of water from the lake and surrounding areas. For example, rice cultivation around Poyang Lake relies on nutrient-rich water for irrigation. However, overuse and misuse of water have led to water shortages and pollution. Moreover, land reclamation and urbanization have reduced the natural wetlands and vegetation that help regulate the water cycle.
Consequences of decreasing water level in the Poyang Lake
The drying up of Poyang Lake has severe consequences for both humans and nature. One of the most obvious effects is the loss of livelihoods for millions of people who depend on the lake for fishing, farming, tourism, and transportation. The low water level has reduced fishery resources and crop yields and disrupted navigation and trade on the lake. Many people have been forced to migrate or seek alternative sources of income. The drying up of Poyang Lake has also increased the risk of poverty, food insecurity, and social conflicts in the region.
Gallery
2
Timelines
2022
July 24
Poyang Lake declared a water supply “red alert” for the first time as a prolonged drought dried up much of the water in the country’s biggest lake. The lake’s water level fell from 19.43 meters to 7.1 meters over the last three months. Precipitation since July was 60 percent less than it was a year ago. The drought affected Poyang Lake and dozens of rivers across central and eastern China. Efforts were required to seed clouds and divert water from elsewhere.
2020
July 24
Poyang Lake experienced a dramatic reversal, reaching its highest water level on record at 22.6 meters. The lake surpassed the previous record of 22.52 meters reached in 1998. The sudden rise was due to robust and stationary weather systems that have produced frequent storms and heavy rainfall across the Yangtze River basin since early June. The flooding was widespread and deadly in the region, especially in Jiangxi Province and around Poyang. Authorities declared a “red alert” for flooding at Poyang Lake and nearby populated areas.
July 14
Poyang Lake experienced a dramatic reversal, reaching its highest water level on record at 22.6 meters. The lake surpassed the previous record of 22.52 meters reached in 1998. The sudden rise was due to unusually strong and stationary weather systems that have produced frequent storms and heavy rainfall across the Yangtze River basin since early June. The flooding was widespread and deadly in the region, especially in Jiangxi Province and around Poyang. Authorities declared a “red alert” for flooding at Poyang Lake and nearby populated areas.
2019
December 10
Poyang Lake reached its lowest water level in 60 years, shrinking to 25% of its usual size. The lake entered its dry season in August, earlier than ever since 1951. The drought was caused by the lowest summer rainfall in the Yangtze River basin since records began in 1961. Human influences such as landscape change, dams, and sand mining also declined the lake.
2007
December 01
In December 2007 and January 2008 – when the water level was at a record low, and the lake covered only 40 square kilometers – monitors found the water flowing from the lake into the Yangtze was Category V: heavily polluted water.
Fears were expressed that China's finless porpoise, locally known as the jiangzhu ("river pig"), a native of the lake along with other waters such as Dongting Lake, might follow the baiji, the Yangtze River dolphin, into extinction. Calls have been made for action to be taken to save the porpoise, of which there are about 1,400 left, with between 700 and 900 in the Yangtze and another about 500 in Poyang and Dongting Lakes. 2007 population levels are less than half the 1997 levels, and the population is dropping at a rate of 7.3 percent per year.