"The ecology of Honghu Lake is unbalanced", "There were lotus flowers and leaves, as well as various aquatic plants. At that time, the water quality was very good, but now it has become muddy water".
Since last year, there have been many discussions about the deterioration of water quality and ecological damage of Honghu Lake on social networks. Under the background that the water quality of the Yangtze River basin continues to improve as a whole, Honghu Lake, as the largest lake in Hubei Province, continues to decline in water environment and water ecology.
On May 17, the Central Ecological and Environmental Protection Supervision Group pointed out in a report of typical cases that Jingzhou City and relevant departments were afraid of difficulties in the ecological protection and management of Honghu Lake, were not determined enough, did not meet the challenge, and did not act slowly. The overall planning of the river basin was not effective, and the main measures to promote the implementation of pollution control and ecological protection of Honghu Lake were not in place. The water environment quality of Honghu Lake is declining and the ecological degradation is prominent.
Hubei is "a province of thousands of lakes", and Honghu Lake is known as "the kidney of Hubei". According to the sorting of the surging news (www.thepaper.cn), since April 2017, the Central Environmental Protection Supervision Group has pointed out the water problem of Honghu Lake to Hubei four times in eight years, but the trend of water quality deterioration of Honghu Lake has not been curbed. Since 2012, the water quality of Honghu Lake has continued to deteriorate, and it has been classified as Class V since 2021.
At the same time, the water ecological status of Honghu Lake has also continued to decline: the coverage of aquatic vegetation accounts for only 12% of the total lake area, less than one fifth of the historical good level since records were made; submerged plants have almost disappeared, the area of wild red lotus has greatly decreased, and the diversity of benthos has decreased, and the number of species is only one fourth of the historical good level since records were made.
Direct discharge of urban sewage
Before the 1950s, Honghu Lake and the Yangtze River were interconnected, which was truly the "Yangtze River Water Bag". With the construction of a series of water conservancy projects, the natural connection between Honghu Lake and the Yangtze River has been blocked, and Honghu Lake has become a semi closed shallow lake.
Map of Honghu Lake and its surrounding main rivers and canals: surging news Wang Yu
The water system of Honghu Lake basin is complex, but the water source of Honghu Lake mainly comes from the main canal of the four lakes, the west main canal, the east main canal, the Tianguan River, the Luoshan main canal and the drainage river. These canals accept the flood and waterlogged water on both banks along the way and discharge it into the Dongjing River or the Yangtze River through the regulation and storage of Honghu Lake.
On May 14, surging journalists came to the urban area of Jianli City, where the Linchang River ran through the city, forming two parallel Linchang River in the center of the wetland park.
In 2023, the water quality of the New Linchang River will be relatively clear after a series of treatment, while the old Linchang River in the south will be in sharp contrast to the New Linchang River. Residents living on the south bank of the River say that the old Linchang River will often smell bad smell, which is "very smelly when the temperature is high".
"Here are two long forest rivers, one is clear, the other is smelly." The residents living near the river pointed to the river and said, "It was smelly some time ago. Just these two days, when the upstream sluice was opened to 'wash the river', the water quality improved a little, and the odor was not smelled temporarily."
Several elderly citizens complained in succession, "just do superficial work", "sewage is still being discharged", and "the mud at the bottom of the river is not clean enough to discharge water".
On May 14, in the urban area of Jianli City, Hubei Province, many residents living around reported to reporters that the old forest and long river smelled for a long time before the inspectors entered the city. Before and after the inspectors entered the city, the upstream sluice was opened to release water to "wash the river", and the river water quality was "temporarily" improved. The pictures in this article are all taken by the surging journalist Diao Fanchao except for the signature
On May 14, Jianli City, Hubei Province, near the hydrophilic corridor in the center of the Linchang River Wetland Park, the Linchang River formed two new and old rivers. Residents nearby said that the water quality of the new Linchang River is good on weekdays after renovation, while the water quality of the old Linchang River has been very poor, forming a sharp contrast, "one clean and one smelly".
The Sihu area where Hong Lake is located is an inter river depression between the Yangtze River and the Dongjing River. The terrain of this area inclines from northwest to southeast. There are vertical and horizontal rivers and canals in the area, with dense water networks. But eventually, they will flow into Hong Lake through the gates of the Sihu Main Canal and Luoshan Main Canal, or flow into the Yangtze River through the regulation and storage of Hong Lake. The same is true of the sewage of Lin Changhe.
On May 17, the Central Ecological and Environmental Protection Supervision Group pointed out that the problem of direct discharge of urban domestic sewage in Jingzhou City was prominent when reporting typical cases. A large amount of rainwater and sewage is directly discharged from the southeast rainwater drainage pump station of the Jiangcheng Road Sewage Interception Sluice in Jianli City, with the chemical oxygen demand exceeding 1.4 times, forming a pollution belt of more than 1 km of floating sludge in Linchang River.
The report pointed out that Honghu Lake is the main receiving water body for drainage in the main urban area of Jingzhou City, Jianli City, Jiangling County and other cities and towns. In December 2018, Hubei Province issued the Plan for the Protection of Honghu Lake, requiring that the rainwater and sewage separation transformation of the combined drainage system in the existing built-up areas should be completed by 2025. At present, only 65% of the pipe network investigation tasks in Jingzhou City have been completed in the urban area, and the problem of wrong and mixed connection is still serious. The pipe network construction and transformation is slow, and the problem of direct sewage discharge in some regions is prominent, which has affected the water quality of Honghu Lake.
On April 19, 2024, the inspection team found that a large amount of rainwater and sewage mixed water in Leijiadang was directly discharged into the river. Drawings provided by the inspection team
The inspector also found that a large amount of mixed rainwater and sewage water in the main urban area of Jingzhou City was directly discharged into the river channel through six rainwater pump stations, including Leijiadang and Caoshi, on rainy days. The monitoring data shows that the chemical oxygen demand and ammonia nitrogen concentrations in the drainage outside the Leijiadang rainwater pump station are 1510 and 17.8 mg/l, which are 29.2 and 2.6 times higher than the Class A standard in the Discharge Standard of Pollutants for Urban Sewage Treatment Plants. The chemical oxygen demand and ammonia nitrogen concentrations in the drainage outside the Caoshi rainwater pump station are 110 and 21.8 mg/l, 1.2 and 3.4 times higher than the standard. The Wanjia Times Community, which was developed and constructed in Jiangling County in succession in 2014, has a building area of 150000 square meters. The sewage directly discharged forms a black and odorous water body, and finally flows into Honghu Lake through ditches.
Agriculture, livestock and aquaculture contribute greatly to the pollution of Honghu Lake
On May 14, in Wangshi Town, Jianli City, Jingzhou, an excavator was digging the bottom mud in the irrigation canal beside the livestock and poultry breeding cooperatives. Previously, inspectors found that fecal sewage was discharged from the farm during random inspection.
On May 14, in Wangshi Town, Jianli City, Jingzhou City, the bottom mud excavated from the irrigation canal beside the livestock farm gave off a foul smell.
In Wangshi Town, Jianli City, Jingzhou, there are 13 livestock and poultry farms above designated size. On May 14, the reporter came to Yuanmeng Livestock and Poultry Breeding Cooperative in Wangshi Town. Since the inspection team found that the pig breeding dung was pumped into the off-site ditch in this farm during the spot check, an excavator began to clean the sludge in the off-site ditch from the 13th, and the stench spread at the operation site.
The monitoring results show that the chemical oxygen demand, ammonia nitrogen and total phosphorus in this ditch are up to 130, 12.9 and 2.7 mg/L respectively. The water in the ditch is discharged into the Longxing River through the sluice, which is also a part of the river network in the Honghu basin.
The aquaculture tail water is also an important source of pollution into the lake. According to the report of Jingzhou Radio and Television Station in October 2023, in 2022, the aquaculture area of Jingzhou will be 1.87 million mu, and the total output of freshwater products will be 1.222 million tons, ranking first in terms of area and output for 29 consecutive years.
Honghu Neidouhu Fishing Ground
The inspection team found that a large amount of untreated aquaculture tail water was discharged into the main canal of the four lakes through ditches, and finally into Honghu Lake, making a great contribution to pollution. Since 2019, both the state and Hubei Province have required to accelerate the green development of aquaculture industry, vigorously implement the standardized transformation of ponds, and promote the standard discharge of tailwater. At present, only 13.2% of the total area of Jingzhou City, Honghu Lake Basin, has completed the transformation and treatment of aquaculture ponds, and no follow-up treatment task has been arranged. The spot check found that some completed aquaculture tail water treatment projects also operated abnormally. The treatment facilities of Guangrong Village Project in Maoshi Town, Jianli City have been shut down for a long time, and the aquaculture wastewater is directly discharged; The bio contact tank and bio brush of Xingou Zhenhua Fishery Project were damaged in a large area and operated abnormally.
In addition, the 2019 Central Ecological Environmental Protection Supervision "looking back" rectification plan requires Jingzhou City to complete the task of returning 199900 mu of embankments to lakes by the end of January 2021. Jingzhou City has reserved 45000 mu for ecological planting and breeding and other reasons. Through spot check, it is found that there are many ecological planting and breeding in the name of "human release and natural cultivation" mode within the embankments of Shengli Embankment, Binhu Fishing Ground and Douhu Fishing Ground, which is actually still the traditional fertilizing and breeding mode.
"Double source superposition" vicious circle
The Hubei Honghu Lake Conservation Plan issued in December 2018 in Hubei Province requires that wetland plant restoration sites should be set up in important estuaries and sparse vegetation areas such as the southeast and southwest corners of Chatan and the inlet of Xiaxin River, 327.8 hectares of submerged vegetation with strong disturbance resistance should be planted in the area between Chatan and Jintan, and 405.4 hectares of floating leaf plant community should be restored in Qingshuibao Demonstration Area, The inspector found that none of the above projects were implemented. The ecological restoration project of restoring 615.4 hectares of floating leaf plant community in Lantian Estuary Demonstration Area has not been carried out.
In September 2022, the relevant departments of Hubei Province issued the Implementation Plan of "One Lake, One Policy" for Honghu Lake in Hubei Province (2021-2025), which requires that the desilting works of Hongcheng River, Zhangdakou River and Digouzi River, which should be completed by the end of 2022, have not been implemented. In January 2021, the relevant provincial departments issued the Opinions on Flood Control, Drainage and Ecological Regulation of the Five Major Lakes in Hubei Province to promote vegetation restoration and implement ecological water replenishment through water volume and water level regulation. The inspector found that the ecological flow into the lake of Xijiakou Gate, Jingxiang River Gate and Gaochang South Gate was insufficient in some periods, which could not meet the water supplement requirements, and the ecological water supplement measures could not meet the water quality improvement requirements.
The water quality in some areas of Honghu Lake has become eutrophic
In history, the water quality of Honghu Lake was clear to the bottom, and it was a huge germplasm resource bank. In recent years, due to the long-term cumulative impact of economic and social development and population growth in the basin, the pollutants from the outside of Honghu Lake continued to increase. At the same time, the lake was constantly disturbed by unreasonable resource development and utilization such as reclamation, cultivation of embankments, and snail dragging, As a result, the self purification capacity of water body is constantly declining.
The transparency of water body is reduced, aquatic vegetation is degraded, and biodiversity is reduced. The inspector pointed out that the coverage of aquatic vegetation in Honghu Lake was reduced, submerged plants almost disappeared, the area of wild red lotus was significantly reduced, and the diversity of benthos was reduced, and the number of species was only a quarter of the historical good level since records.
The degradation of aquatic vegetation caused the loss of vegetation protection in Honghu Lake sediment, which was easily disturbed by wind and waves. Sediment resuspension increased and endogenous release increased, thus forming a "vicious cycle" of water quality deterioration and aquatic vegetation degradation, forming a "double source superposition phenomenon".
Today, the turbid and yellow water of Honghu Lake is still surging, and the scene of "Honghu Lake waves beating the waves" is still there, but it is difficult to find the scenery of lotus leaves and lotus flowers in the past.
