The flood water on News Road was deep.
The staff dredged the drain.
Traffic police at the scene to divert traffic.
The drainage company staff drained the submerged water under the Mingbo overpass.
Flood control is about people's livelihood, it's about the overall situation, and it has a great responsibility. Every year in the rainy season, floods occur in the main urban area of Kunming after heavy rain hits the city, and some roads are cut off. The problem of "flooding in heavy rain" has always been the focus of attention.
After a heavy rain from July 19th to 20th, 68 submerged waters appeared in the main city again, which had a great impact on the lives and travels of many citizens. Why are there multiple places in the main city area that will be flooded during heavy rains? How to solve the pain point of the city? Responsible person of a limited liability company (hereinafter referred to as "drainage company").
"It will flood in heavy rain" has become
Prominent public disasters in urban areas
Beginning at 15:00 on July 19, Kunming dropped the longest rain this year. At around 2 am on the 20th, the original raindrops of Zulili suddenly poured down, and there were as many as 31 rainfall stations in the main city with rainfall exceeding 100 mm and reaching extreme heavy rainfall levels. According to incomplete statistics, this rainfall also refreshed the daily rainfall records in July since Kunming had historical observation records, and entered the "top three" of the entire observation history. The heavy rain also caused 68 floods in the main city, with a total of 26 roads broken at the peak.
This is not the first time urban flooding has occurred in Kunming after heavy rains. From recent news reports, the reporter compiled some records of large-scale flooding in Kunming:
July 18-19, 2013
Kunming City encountered heavy precipitation. The rainfall caused more than 160 floods in the main urban area, and the depth of floods in many places reached more than 0.5 meters;
June 25, 2015
A heavy rain caused 33 floods on municipal roads in the main urban area;
May 21-24, 2016
The heavy precipitation weather in Kunming caused 45 floods in the main urban area;
July 19-20, 2017
Heavy rainfall occurred in the main city, causing 87 floods in the main city; on September 9, after a heavy rain, 68 floods occurred in the main city;
July 11, 2018
Heavy rain caused 24 floods of water in the eastern part of the main city; on August 21, the main urban area fell to heavy rain, causing 32 roads to flood;
On the evening of June 23 this year
A rainstorm caused flooding in 27 roads in the main city ...
The data show that urban waterlogging, especially the accumulation of water on municipal roads, has become a prominent problem of public disasters in the main urban areas. When serious, it can cause bridges and culverts to be blocked and traffic to be paralyzed, which affects the city's normal production and living order. In 2017, Kunming was listed as one of the 60 cities in China with severe waterlogging disasters and high levels of social concern. The crux lies in the lack of source control facilities; the design standards for drainage pumping station facilities are low, the system is incomplete, and the level of maintenance is low. Not high; there is a distance between comprehensive prevention facilities and the plan, etc. It is urgent to build a comprehensive urban flood control system.
"There are heavy rains every year, but when can Kunming 'not look at the sea'?" Has become one of the most important livelihood issues for Kunming citizens.
Inadequate flood discharge capacity is the main cause
Qiu Hao, deputy manager of the publicity and information department of the drainage company, introduced three types of urban waterlogging: when the water depth reaches 20 cm, it is difficult for pedestrians to walk; when the water exceeds 30 cm, it is difficult for bicycles and cars to drive; and Once the accumulated water exceeds 50 cm, the traffic will be completely paralyzed. At the same time, the accumulated water often becomes sewage, which causes pollution to urban sanitation.
Regarding the problem of flooding in heavy rain and torrential rain in some regions for many years, Qiu Hao said that although the causes of flooding vary from place to place, insufficient flood discharge capacity is still the main reason.
In recent years, heavy rainfall in the main urban area has exhibited new changes: the number of heavy rain days and rainfall intensity in the main urban area increased year by year; the rainfall in the main urban area is characterized by single-point short-term heavy rainfall with short duration, high intensity, and strong locality. Heavy rain is the main type, and heavy rainfall usually lasts 2 to 3 hours, and the hourly rainfall exceeds 50 millimeters; the frequency of short-term heavy rainfall and becoming the center of heavy rainfall in the main urban area has increased significantly.
The relevant analysis report shows:
● Kunming's main city is surrounded by mountains on three sides, and the mountains are steep. Once heavy rainfall and flood occur, it can directly flow into the city.
● The topography of the urban area decreases from north to south, and the slope of the river is gentle, and the speed of flooding is slow. In addition, the normal water level near the Dianchi Lake below the city and the maximum elevation difference between the main city center and the main city are only 3 meters. Dianchi rivers generally have the effect of "top support", which affects the longest rivers up to 11.4 kilometers, greatly reducing the flood capacity of urban rivers.
● The mountainous runoff area of the main city is 374 square kilometers and the rainfall is 111 millimeters in 6 hours (the main peak rainfall of the flood). The total amount of flood generated is about 21.5 million cubic meters. 51.8 million cubic meters, with an average flow of 667 cubic meters / second. Floods flow into Dianchi Lake through 21 rivers in the main city, and the flood discharge capacity of the main city river is about 420 cubic meters / second. The flood discharge capacity cannot meet the requirements, so urban flood disasters occur frequently. .
"In addition to the insufficient flood discharge capacity, there are three reasons for flooding in many places after heavy rains on July 20 this year." Qiu Hao introduced. One is that the water level of the tributaries of the river is too high. Laoyunliang River, Haiming River, Mingtong River, Cailian River, Jinliu River, Moss River and other rivers have high operating water levels, which seriously affected the drainage capacity of the surrounding area drainage system, and even caused backwater and river flooding, causing seawater sources. Submerged water in areas such as Middle Road, West Second Ring Road, Mingbo Interchange, East Second Ring Road, Shulin Street, etc .; Second, the amount of short-term heavy rain is too large, the water comes too fast, and the amount of water formed in heavy rainfall areas has far exceeded Drainage pipe network and pumping station design drainage and existing traffic capacity, such as the Xifu Road south bypass city tunnel, Minhang Road, Qianxing Road and other areas; the third is the sewage treatment plant, pumping station and drainage pipe network super design Capacity, high water level operation, causing water accumulation in low-lying areas, such as Guangfu Road (Guangwei Interchange-Century City Section), Yucun South Roundabout and other areas.
Submerged water occurrence continues to decline
Disposal efficiency has also improved significantly
"In this heavy rainfall from July 19th to 20th this year, 31 stations in the urban area had rainfall of more than 100 millimeters. The maximum rainfall was 161.6 millimeters in Xizhuang, Guandu District, and the remaining rainfall was 130 to 140 millimeters, reaching heavy rainfall. Local heavy rain level. Compared with several heavy rains in previous years, this rain lasted longer and the amount of rain was greater, but we can see that the degree and range of submerged water are decreasing, and the efficiency of disposal has also improved significantly. "Qiu Hao said that on July 20 this year, the peak of the flooded water point appeared between 5 am and 6 am. At that time, a total of 26 roads were cut off because of the accumulated water. By 18:00, only 4 flooded roads were cut off.
Degree and extent of submerged water decline
(Taking the heavy rainfall that occurred on July 19, 2013 and July 20, 2017 as an example, compared with July 20 this year)
July 19, 2013: 6 stations with rainfall exceeding 100 mm, causing more than 160 floods;
July 20, 2017: 10 stations with rainfall of more than 100 mm, and flooded water in 87 places in the main city;
July 20 this year: 31 stations had rainfall of more than 100 millimeters, and inundation points had dropped to 68.
Disposal efficiency has improved significantly
● North Station Tunnel Flooded
July 19, 2013: After the North Station tunnel was flooded, the flood control team of the drainage company shared 76 hours to drain the accumulated water in the tunnel;
July 20, 2017: The North Station Tunnel was flooded again, and the accumulated water was drained in 14 hours;
This year: No flooding occurred in the North Station Tunnel.
● Water accumulation along the East Second Ring Road
July 20, 2017: Water accumulated along the East Second Ring Road, which took 24 hours to complete;
July 20 this year: With the same degree of flooding along the East Second Ring Road, drainage was completed in 10 hours.
Construction of comprehensive urban waterlogging prevention and control system
Many places in the main city have bid farewell to "flood in heavy rain"
In view of the many problems in the operation and maintenance mode of public drainage facilities in the main city of Kunming, there are many problems such as multiple networks and their own policies. After repeated demonstrations, the Kunming Municipal Party Committee and Municipal Government have decided to fully implement the “one city, one network and one network” of public drainage facilities in the main city of Kunming from 2015. Management mode. The so-called "one city, one head, one network" refers to the establishment of a city-based and district-based management system in a city to manage Kunming's drainage. The construction, maintenance, and maintenance of the pipe network are entrusted to the drainage company, who will oversee the drainage network of the entire city.
So, in order to alleviate the urban waterlogging in Kunming, what has the drainage company carried out in recent years?
Drainage company statistics show that since the implementation of the "one city, one head and one network" management model in Kunming, the drainage company has been responsible for expanding the management and operation scope to Wuhua, Panlong, Guandu, Xishan, vacation, high-tech and other areas, with a service area of 45 square meters. The number of kilometers increased to 312 square kilometers, the number of drainage pipes (canals) under management increased from 852 kilometers to 4456.7 kilometers, and the number of drainage pump stations increased from 67 to 98.
According to Qiu Hao, after the transfer of the facilities, the relevant assessment results show that the drainage capacity of public drainage pipes in the main urban area is less than once a year, accounting for 43% of all drainage pipes, less than 2 years, 61%, and less than 5 years. Cases account for 72%, only 28% of the pipe network drainage capacity is greater than once in 5 years. At the same time, drainage pumping stations have insufficient drainage capacity, aging equipment, and tributary ditches that connect rivers and urban rainwater piping systems.
In order to effectively improve these problems and alleviate the urban flooding in Kunming, in accordance with the requirements of the "Thirteenth Five-Year Plan" for the protection and treatment of Dianchi Lake, the drainage company plans to:
● During the "Thirteenth Five-Year Plan" period, invest 950 million yuan to implement the old drainage pipe network reconstruction and pumping station construction project in Kunming's main city, and the dredging and obstacle removal project for the drainage system in Kunming's main city.
● Renovate about 100 kilometers of old drainage pipe network, improve about 100 nodes of the drainage system, and install facilities and equipment such as hydraulic flushing in the main drainage pipe network under some urban traffic and crowded roads.
● Based on the general survey and performance evaluation of public drainage pumping stations in the main urban area, a total of 47 pumping stations were renovated, rebuilt, and newly built.
As of now, 22 roads, 39.628 kilometers of drainage pipe network reconstruction and new construction have been completed, including the renovation of the flooding point of the Guomao International Trade Center area and the flooding point of the Platinum Avenue. Upgrading and reconstruction of 32 old pumping stations; At the same time, 97 drainage system nodes including the Weilong Hotel Section along the River Road and the Yun Road Central Section of the South Ring Road were completed. "Completed reconstruction projects have also shown good results this time. For example, Guanping Road, Jinhui Road, and Guanpei Road in the closed area were also areas with severe flooding. Since then, the area has not experienced any serious flooding so far, "Qiu Hao said.
At the same time, the drainage company also made full use of existing resources and actively promoted the use of big data to share results. Combined with the future development trend of urban drainage, using the Internet, the Internet of Things, and program-controlled technologies, to explore the use of technologies such as unattended pumping stations, monitoring and disposal of urban inundated water, and online monitoring of the health of drainage facilities, to continuously improve operating efficiency and service levels Establish core technological competitiveness. After more than three years of operation, the drainage facilities within the jurisdiction have been maintained normally, the incidence of drainage cases has gradually decreased, and the efficiency of case disposal has increased significantly, improving the professional level and service capacity of public drainage facilities management in Kunming. "In the future, the drainage company will also closely focus on the specific requirements of Dianchi Lake governance and urban public management, continue to improve the 'one city, one head, one network' management model, implement various projects as planned, and strive to build a modern urban waterlogging comprehensive prevention and control system." Qiu Hao said.