Focus Interview | Make Every Effort to Cope with Extreme Rainfall and Flood Control | Flood Storage and Detention Areas | Rainfall
Recently, due to the impact of Typhoon Dussuri, extreme rainfall processes have occurred in North China, Huanghuai and other areas, causing floods and geological disasters, resulting in significant casualties in Beijing, Hebei and other areas.Since July 29, seven rainstorm red warnings have been issued in many places in Beijing, Tianjin and Hebei in three days. In the evening of July 31, the Central Meteorological Observatory continued to issue rainstorm red warnings and severe convection yellow warnings. How to cope with extreme rainfall in the northern region.
Affected by the residual circulation of Typhoon Dussuri, the fifth typhoon of this year, large-scale heavy rainfall has occurred in Beijing, Tianjin, Hebei and other areas. On July 30th, the National Defense Administration raised the emergency response level to Level 2 for Beijing, Tianjin, Hebei, Shanxi, and Henan. At 18:00 on July 31, the Central Meteorological Station issued a red warning for rainstorm, a yellow warning for severe convective weather, a yellow warning for gale, and a meteorological warning for waterlogging risk. The Ministry of Water Resources and the China Meteorological Administration jointly issued a meteorological warning for the red mountain flood disaster. The Ministry of Natural Resources and the China Meteorological Administration jointly issued a geological disaster meteorological risk warning. This round of rainfall poses a severe challenge to the Beijing Tianjin Hebei region.
From 8:00 on July 28th to 8:00 on August 1st, the cumulative rainfall in the Haihe River Basin was 131 millimeters, with Beijing, Tianjin, and Hebei receiving 235 millimeters, 128 millimeters, and 125 millimeters respectively. That is to say, in just 4 days, Beijing, Tianjin, and Hebei accounted for 40%, 24%, and 25% of the annual rainfall in their respective provinces and cities.
Wan Qunzhi, Deputy Director of the Flood Control and Drought Relief Department of the Ministry of Emergency Management: The terrain of the Haihe River Basin is characterized by the southern foothills of the Taihang and Yanshan Mountains, with short and rapid flood sources and fast confluence. The formation time of the flood peak is very short, and from the perspective of prediction and prevention, it is also very difficult. For example, the largest flood peak will appear in the Guanting Gorge section of the Yongding River in 4 hours. Another characteristic of its terrain is that the flood in the hilly area rises rapidly and has a high magnitude.
Typhoon Dussuri, which carries a large amount of water vapor, is blocked by the Taihang Mountains in the west of Beijing Tianjin Hebei, and the water vapor is concentrated in front of the mountains. That is to say, the prolonged and abundant water vapor transport, coupled with terrain amplification, has caused the extreme precipitation in the Beijing Tianjin Hebei region.
Mentougou is the area with the highest proportion of mountainous areas in Beijing, accounting for 97% of the total area. After heavy rainfall, floods destroyed the infrastructure such as roads, communication, and electricity in the mountainous areas, and multiple villages lost contact with the outside world. Due to prolonged soaking in rainwater and loosening of soil, Jiagou Village located in Tanzhesi Town, Mentougou District, Beijing is at risk of houses and roads collapsing at any time. On the early morning of August 1st, the Mentougou District urgently organized rescue forces to advance into Jiagou Village and transfer the trapped people.
As of 6:00 pm on August 1st, this round of disasters has caused a total of 44673 people in 13 districts of Beijing to be affected, and a total of 127000 threatened residents have been relocated throughout the city.
At 5:10 am this morning, four transport helicopters carrying 26 officers and soldiers urgently flew to the Mentougou Riverside City Railway Station and other places in Beijing to carry out tasks such as airdrop of rescue supplies and patient transportation. The plan was to airdrop 1900 urgently needed supplies such as food, 900 raincoats, and 700 blankets. If the weather conditions on site permit, rescue personnel will use aerial delivery and landing distribution to deliver rescue supplies to the public.
Wan Qunzhi, Deputy Director of the Flood Control and Drought Relief Department of the Ministry of Emergency Management: In accordance with the decisions and deployments of the Central Committee of the Communist Party of China and the State Council, the National Flood Control Administration and the Ministry of Emergency Management adhere to the principle of putting people first and life first, organize and coordinate relevant regions and departments, and make every effort to prevent and respond to the extreme heavy rainfall process in the North China region of the Haihe River Basin.
On July 30th and 31st, the Ministry of Water Resources issued three consecutive flood notifications: the first flood of 2023 occurred in the Ziya River in the Haihe River Basin, the first flood of 2023 occurred in the Yongding River in the Haihe River Basin, and the first flood of 2023 occurred in the Daqing River in the Haihe River Basin.
At the same time, a total of 21 rivers in the Haihe River Basin experienced floods exceeding the warning level, with a maximum warning range of 0.07-4.33 meters. Among them, 5 rivers, including Juma River, exceeded the protection level, and 8 rivers, including Yongding River, Qingshui River, and Dashi River, experienced the largest floods recorded in actual measurements.
Here we see a key word is the Haihe River Basin, which is one of the seven major river basins in China. How should we respond to the simultaneous occurrence of numbered floods in three water systems in the Haihe River Basin?
Wang Zhangli, Deputy Director and spokesperson of the Water and Drought Disaster Prevention Department of the Ministry of Water Resources: The total number of large and medium-sized reservoirs in the entire Haihe River Basin is 155. During the process of defending against large-scale floods in the basin, all of these large and medium-sized reservoirs have been put into operation. Among them, there are 79 large and medium-sized reservoirs in the Beijing Tianjin Hebei region that have been put into flood control, with a total amount of 2.086 billion, nearly 2.1 billion. Leave so much water in the reservoir to alleviate the pressure on flood control and safety in key downstream areas.
These five rivers in the Haihe River Basin converge into the Haihe River at the Sancha River mouth in Tianjin city, and then flow into the Bohai Sea through the Haihe River. Tianjin urban area is basically located in the lower reaches of the Haihe River, which is the lower end of these five main streams. The pressure brought to Tianjin by the Five Rivers is enormous. At 1:00 on August 1st, Tianjin upgraded its level III emergency response for flood control to level I emergency response for flood control. At present, the Yongding River flood storage and detention area has entered a critical period of operation, and the flood head is about to reach Tianjin, covering an area of 113 square kilometers within Tianjin. All residents within the Tianjin area of the Yongding River flood storage and detention area have completed their relocation, and the river engineering has also been reinforced.
Liu Zhanyou, Director of Tianjin Water Engineering Operation and Dispatch Center: The peak flood discharge under the Lugou Bridge on the Yongding River is currently around 2300 cubic meters per second. This morning, the head of the Yongding River has reached Lianggezhuang, which is the starting point of the Yongding River floodplain in Hebei Province and Tianjin City. In other words, reaching Lianggezhuang means the opening of the Yongding River floodplain. It is expected to enter Tianjin around midnight tonight. Prior to today, we had already arranged for the transfer of all residents from Wuqing District and Beichen District, as well as the Yongding River pan area involving both districts.
On July 31st, the Ministry of Water Resources announced that four national flood storage and detention areas have been put into use in the Haihe River Basin, including Ningjinpo in the Ziya River system, Dalu Ze in the mainland, and Xiaoqing River and Langouwa in the Daqing River system. At 2am on August 1st, the Dongdian flood storage and detention area was put into operation. On August 1st at 11 o'clock, the Xian County wide area will be opened. As of now, 6 of the 13 flood storage and detention areas listed in the national flood storage and detention area list in Hebei Province have been put into use. The flood control in the Haihe River Basin has entered a critical moment.
Flood storage and detention areas, like reservoirs, rivers, and embankments, are important components of the flood control system. Why do we still need a flood storage and detention area when we already have embankment projects? This is because floods enter the plains from the mountains and are mainly constrained by embankments. But the embankment cannot be infinitely raised, the higher the embankment, the greater the safety risk. Therefore, when the flood exceeds the defense capacity of the embankment, it is necessary to use the flood storage and detention area to store the flood, ensuring the timely, safe, scientific and orderly use of the flood storage and detention area.
Continuous rainfall in the Dashi River Basin in Fangshan District, Beijing, the Yongding River Basin in Mentougou District, and the Juma River Basin in Yixian County, Laiyuan City, Hebei Province has also caused downstream water levels to exceed normal values. The Lan Gou Wa flood storage and detention area in Gaobeidian City, Hebei Province, which bears the responsibility of flood safety in the Baigou River and Nanjuma River basins, has experienced several consecutive days of heavy rainfall since July 29th, with an average rainfall of 339.7 millimeters. Coupled with the pressure brought by the upstream, Gaobeidian City upgraded its flood prevention level II emergency response to flood prevention level I emergency response on the second day of rainfall.
Kang Feng, Executive Vice Mayor of Gaobeidian City, Baoding, Hebei Province: When the water levels of two rivers reach the warning level and the higher-level flood control command issues an order, we need to carry out flood storage and detention in this area, so personnel transfer and resettlement are necessary.
The Langouwa flood storage and detention area in Gaobeidian City covers an area of 138 square kilometers, with 128 villages and 109000 people. The first batch of emergency relocation of more than 40000 people involved 80 villages in 3 townships, with a large number of people being relocated and resettled, making it difficult. At this time, there are only 30 hours left until the completion of the first batch of relocation and resettlement as stipulated in the Emergency Plan for Flood Control and Drought Relief in Gaobeidian City.
Kang Feng, Executive Vice Mayor of Gaobeidian City, Baoding, Hebei Province: During the relocation and resettlement period, we organized party and government officials and public security officers to work day and night on the front line, actively carrying out mass work. According to the emergency plan, five households of the masses were grouped together, each with professional vehicles and personnel for relocation.
How to achieve the goal of "not leaving any household or missing any person" is also a test for grassroots rural cadres. The first batch of 80 villages to be transferred, involving a total of 50132 people from the Lan Gou Wa flood storage and detention area, rural dilapidated houses, and disadvantaged groups, will all be transferred to temporary resettlement sites before 6pm on July 31st according to the previous plan.
This flood disaster has caused severe geological disasters in Handan, Xingtai, Shijiazhuang, Baoding, Beijing Fangshan, Mentougou and other places in Hebei Province. According to the prediction made by several relevant departments after consultation, on the night of August 1, rainstorm to heavy rainstorm will still occur in most of Beijing, Tianjin, central and southern Hebei and northeastern Hebei, which may further aggravate the flood disaster.
Wan Qunzhi, Deputy Director of the Flood Control and Drought Relief Department of the Ministry of Emergency Management, said: "Seven down and eight up" is a critical period for flood control. Now on August 1st, the critical period has just passed halfway, and the severe test is still ahead, especially with geological disasters lagging behind. The intensity of this rainfall is extremely extreme, and the soil in the hilly area is extremely saturated. Once there are any influencing factors, geological disasters may occur. It is necessary to do a good job in monitoring, prevention, and risk avoidance to avoid secondary disasters. At the same time, this stage is also a crucial stage for emergency rescue, disaster relief, and recovery and reconstruction. Therefore, it is necessary to pay attention to the safety of emergency rescue, including the safety of local residents, take necessary protective measures, and ensure safety, which is the top priority.
Flood prevention and disaster relief require both rescue and prevention. It is necessary to strengthen overall planning and coordination, strengthen consultation and judgment, do a good job in monitoring and early warning, be prepared for the future, and take preventive measures in advance. At the same time, emergency duty and command should be strengthened to minimize losses.
Editor | Wang Ningfan Heling Tian Yuxia Zhenyu
Camera | Pan Ming and Liu Wen
Editing | Miao Jialiang and Zhang Wenqing
Planning | Yu Renshan
