I went to Dunhuang to check in and found that Crescent Lake has become "fat"?

Science Times reporter Hu Lijuan

With the National Day holiday approaching, many people went to Dunhuang, Gansu to "check in". They heard that the Crescent Lake in Mingsha Mountain, which is famous for its crescent-shaped curve, has become "fat" and shaped like "the moon on the eighth or tenth day of the lunar month", and they couldn't wait to see this wonder of the desert.

Why did Crescent Lake become "fat"?

In recent years, the average observed water level of Crescent Lake has steadily risen, exceeding 3 meters in 2021, and has stabilized at around 3.2 meters in the past two years. The water area has now stabilized at 27.45 acres, becoming plump and round.

Regarding the reason why Crescent Lake has become "fatter", Cui Guipeng, an associate researcher at the Institute of Ecological Protection and Restoration of the Chinese Academy of Forestry, explained in an interview with the Popular Science Times that the water in Crescent Lake is mainly supplied by groundwater. Every September, the surface of Crescent Lake will probably become slightly "fatter" because the local water consumption for production and life is lower than that in the hot summer, and the temperature drops in autumn, and the evaporation is also reduced, which makes the groundwater level rise slightly and the width of the water surface expand relatively.

Crescent Lake was once in danger of disappearing because the thousand-year-old spring had been gradually shrinking over the past period of time. By the end of the 1990s, the lake bottom was exposed, and the water area was only about 2.56 acres at its lowest point. In response to this, researchers used various methods to replenish water to Crescent Lake, and finally "learned from nature". On the one hand, they followed the law of underground water seepage to protect the water source; on the other hand, they supplemented it with artificial water source regulation. An artificial water storage facility was built 5 kilometers away from Crescent Lake, which can regulate the water level of Crescent Lake through natural infiltration of the stratum, and to a certain extent played a "near-natural" regulation effect.

How was Crescent Lake formed?

The Crescent Lake is formed by the groundwater supply from the Dunhuang Oasis. With the interaction of three sets of wind directions, the quicksand under the Mingsha Mountain is blown upwards, thus creating the spectacle of the spring being unable to be covered by sand.

Coincidentally, due to the special wind field of Mingsha Mountain, the quicksand does not enter Crescent Lake all year round, which can be said to be "made in heaven". Cui Guipeng further explained that Crescent Lake is located on the ground between the tall sand dunes of Mingsha Mountain, and its formation is related to the Dang River. Geologists have found that the place where Crescent Lake is located was once the river channel of the Dang River in ancient times. As the tall sand dunes moved here, blocking the river channel, the Dang River opened a new river channel, and the abandoned river channel was shaped into the outline of Crescent Lake by the sand dunes. The water of the Dang River passes through the strata under Mingsha Mountain, continuously supplying water, forming the current appearance of Crescent Lake.

Under the surface of Crescent Lake, clumps of water plants are floating, making the water even more beautiful. Many tourists said that no matter whether Crescent Lake is "fat" or "thin", it is still so beautiful and moving, and it is worth the trip to "check in".