With the onset of winter, many lakes and waters are subject to icing.

Lake icing is a phenomenon in which lake water gradually solidifies at low temperatures to form an ice sheet. Lake icing not only changes the state of the water body physically but also has a great impact in ecological and economic terms.

Lake icing has a great impact on the ecological environment. When the lake freezes, the biological activity in the lake slows down and the oxygen content of the water body decreases over time. For the aquatic organisms in the lake, this can lead to their death or migration.

In addition, lake icing affects lake sediment deposition and water mixing, affecting the ecosystem balance of the lake.

Lake icing also has an impact on economic and social life. In some cold regions, lake ice can bring the fun of ice activities, such as ice skating, fishing, skiing, etc. These activities can become an important resource for local winter tourism.

There are also some problems with lake ice. Ice on the lake may cause the water level in the lake to drop, thus affecting the water use in the surrounding area.

Lake ice may cause serious damage to the lake ecosystem, such as causing eutrophication and death of aquatic organisms.

Ice on the lake may also cause inconvenience to human travel and transportation, such as obstructing boat traffic and preventing farmers from irrigating.

Generally speaking, the shallower the depth of the lake, the weaker the current, the lower the temperature, and the colder the surrounding climate, the easier the formation of ice on the lake's surface.

The main reason why lakes all start to freeze from the surface is because of the change in the density of water.

In nature, the maximum density of water is around 4 degrees, when the water temperature drops below 4 degrees, the density of water will gradually decrease.

When the water temperature of the lake surface drops to 0 degrees, the density of water reaches its minimum value, and ice lighter than the water at the bottom of the lake will be formed, so the lake surface freezes first. In addition, the surface of the lake has a larger contact area with the air, and the water temperature at the surface of the lake also drops faster than the water at the bottom of the lake, which is also one of the reasons why the surface of the lake freezes first.