About the barrier lake

Definition of barrier lake

Barrier (sè) lake

Barrier lake is a landslide caused by volcanic lava flow or seismic activity. A lake formed by blocking a river valley or river bed to store water. Lakes formed by volcanic lava flows are also called lava barrier lakes.

It must be emphasized that the blockages in barrier lakes are not fixed forever. They will also be subject to erosion, erosion, dissolution, collapse, etc. Once the blockage is destroyed, the lake water will overflow and pour down, forming a flood, which is extremely dangerous.

The formation process of barrier lake

1. Original water system.

2. The original water system is blocked by blockages. The blockage may be a volcanic lava flow, a landslide caused by seismic activity, a debris flow, or other materials.

3. After the river valley or river bed is blocked, the water gathers and overflows in all directions.

4. When water is stored to a certain extent, a barrier lake will be formed.

Areas where barrier lakes are common

Barrier lakes formed by landslides are mostly found in the canyon areas of southeastern Tibet, and are very recent, such as in 1819 in the northwest of Shimla , a lake 24-80km long and 122 meters deep was formed due to landslides. Yigongcuo in Bomi County in southeastern Tibet was formed in 1990 when a huge debris flow broke out due to an earthquake and blocked the Charlongqiu River. Guxiangcuo in Bomi County was formed in 1953 when a glacial debris flow blocked it. (In fact, it is also Is a glacial lake). Ranwucuo in Basu County was formed in 1959 when heavy rains caused landslides that blocked the river valley.

Taiwan has frequent seismic activities. In December 1941, a strong earthquake occurred in the northeast of Chiayi, causing a landslide and blocking the east flow of Zhuoshui Creek. A 100m-high embankment was formed in the stream at an altitude of 580m. The river was interrupted, and 10 months later, the stream water in the upper reaches stagnated, forming a barrier lake with an area of ??6.6km2 and a depth of 160.0m above the natural dam.

The latest barrier lake is the one caused by the Wenchuan earthquake on May 12, 2008.

Hazards of barrier lakes

The obstructions in barrier lakes are not fixed forever. They are also subject to erosion, erosion, dissolution, collapse, etc. Once the blockage is destroyed, the lake water will overflow and pour down, forming a flood, which is extremely dangerous. Barrier lakes refer to lakes formed by landslides and landslides caused by earthquakes and other reasons, blocking river valleys or river beds and storing water.

Once the barrier lake (Haizi) formed in the disaster area bursts, the consequences will be serious.

As secondary disasters continue, the water level of the barrier lake (Haizi) may rise rapidly, and major floods may occur at any time.

Once the barrier lake (Haizi) bursts, it will form a flood peak downstream, which is no less destructive than a disaster.

Examples of lava barrier lakes

Wudalianchi in northeastern my country was formerly known as Niaode Linchi. It is located on the outskirts of Wudalianchi, a tributary of the Nanor River, the upper reaches of the Baihe River, and is only a short distance from the Xiaoxinan Mountains in the north. 30.0km, it is named after the basalt lava flow from the two volcanoes Laoheishan and Huoshaoshan blocked the Baihe River, blocking the water flow and forming five small lakes connected to each other in the shape of a string of beads.

The volcanic activity of the Wudalianchi volcano group began from the end of the Jurassic to the beginning of the Cretaceous. According to historical records, the most recent volcanic eruption began in 1719 (the 58th year of Emperor Kangxi’s reign in the Qing Dynasty). The record in the Qing Dynasty’s "Heilongjiang Foreign Records" is more detailed: "Southeast of Mergen, one day, fire suddenly broke out in the ground and rocks flew up. , the sound shook the whole country, and after a few days the fire went out, and the land turned into a swamp. This happened in the fifty-eighth year of Kangxi." This volcanic eruption blocked the Baihe River, a tributary of the original Namo River, forcing its river bed to move eastward. The river was blocked and formed into five rosary-shaped lakes running through the Shilong River.

The water of Wudalianchi Lake is clear. When viewed from the top of the nearby volcano, it looks like a bright mirror, reflecting the skylight and cloud shadows, which is extremely beautiful.

Jingbo Lake in Heilongjiang Province was formed by the Quaternary basalt flow near Diaoshui Tower, which formed a natural barrier embankment 40m wide and 12m high, blocking the outlet of Mudanjiang River and raising the water level. A typical lava barrier lake of about 90.3km2. Jingbo Lake is surrounded by mountains, with dense forests and beautiful scenery. There are not only crater forests, karst caves and the ruins of the Bohai Sea in the Tang Dynasty, but also Dahu Mountain, Xiaohu Mountain, Pearl Gate, Diaoshuilou Waterfall and Jingbo Lake in the lake. Boshan Villa and other "Eight Famous Scenic Spots" have become a famous tourist lake in my country.

The "barrier lake" formed by the Wenchuan earthquake

The devastating Wenchuan earthquake in Sichuan on May 12, 2008 caused parts of Beichuan to be flooded by barrier lake water, and the earthquake formed a large area of ????barrier lake. Block the lake. The massive earthquake in Wenchuan, Sichuan caused 34 dangerous areas of barrier lakes. The National Ministry of Water Resources and the Sichuan Provincial Department of Water Resources formed an earthquake relief ministry and believe that the 33 barrier lakes formed by the earthquake are currently in no danger. A "death squad" has been organized to monitor each barrier lake 24 hours a day. Once there are signs of a dam break, an early warning will be issued immediately and the people will be evacuated in time.

Once the barrier lake formed in the disaster area bursts, the consequences will be serious. With the continuous occurrence of secondary disasters, the water level of the barrier lake may rise rapidly, and major floods may occur at any time. Once the barrier lake bursts, it will form a flood peak downstream, which is no less destructive than a disaster.