How did Jimmy Island in Jilin come into being? Songhua River+Fengman Hydropower Station in the upper reaches of Songhua River.
1, natural conditions
In Jilin, in winter, although Songhua Lake is like a mirror and frozen as iron, the water temperature of 4℃ can still be maintained in the water dozens of meters below the ice, and the temperature difference between the water temperature and the ground is often around 30℃, thus forming an unfrozen river surface for dozens of miles below the urban area. The temperature difference makes the river foggy, and the white fog on the river has been lingering for a long time.
The ten-mile-long levee along the Yangtze River is covered with pine and willow trees. Under the influence of certain conditions, such as air pressure, wind direction and temperature, a large amount of fog on the river surface condenses on the surrounding branches with different thicknesses in the form of frost, forming a large area of rime wonders.
Because of its unique natural conditions, Jilin rime has the characteristics of long duration, large thickness and high frequency.
2. The human condition
In winter, the time of MINUS 20 degrees in Jilin Province is as long as 60 to 70 days. Strangely, the Songhua River water that passes through the city can actually flow continuously in the cold winter. It turns out that fifteen kilometers upstream of Jilin City is the famous Fengman Hydropower Station.
The dam of the hydropower station cut off the river and formed a huge artificial lake-Songhua Lake. Nearly/kloc-0.00 billion cubic meters of water makes the surface of Songhua Lake freeze in winter, but the underwater temperature remains above 0℃.
In particular, the temperature of the lake water rises after passing through the generator set of the hydropower station, and the river water carries huge heat energy downstream, forming a strange landscape on the river surface that is tens of kilometers cold and unfrozen. At the same time, it also has two necessary and contradictory natural conditions for the formation of rime: sufficient low temperature and sufficient water vapor.
Is rime island an island? Rime island is a naturally formed island on the Songhua River. The reason why this river doesn't freeze all the year round is that there is a full dam in the upper reaches of it, which cuts the upper reaches of the river into reservoirs. This plump dam is a concrete gravity dam with a length of1080m and a height of 91.7m. It was built in 1937, when it was the highest dam in Asia.
Jilin is very cold in winter, and the high water level of the reservoir can well retain the heat of the river. The temperature difference between the river flowing from the reservoir and the climate environment makes the rime island River near the reservoir form transpiration water mist, which is the basic condition for the formation of rime.
The formation history of Fengman Dam in rime island was built by hundreds of thousands of laborers in China under the crazy slavery of Japanese invaders. Except for fatigue, illness and torture, the rest of the workers were tricked into the tunnel for "final completion acceptance" and drowned alive. Few workers participated in dam construction.
Rime island viewing guide The best viewing period of Jilin rime is from 65438+February to the following February. The best time to watch the rime is in the morning, and the time when the rime disappears depends on the strength of the wind that day. If the wind is strong, the rime will start to fall around 9 o'clock. If there is no wind or breeze, the rime can be maintained at 1 1- 12.