There are many types of lakes. Different types of lakes have different forms, natural conditions and resources. The common classifications are as follows.
According to the formation of lakes, they can be mainly divided into the following six categories:
• Constructing a lake: a lake formed directly by the movement of the earth’s crust and causing water to accumulate in the ground;
• Glacier lake: a lake formed by glacial erosion and sedimentation;
• Crater Lake: The lava and debris from the volcano accumulate around the crater, making the crater form a lake formed by the accumulation of water;
• Barge Lake: Lakes formed by earthquakes, landslides, landslides, mudslides, hail or volcanic eruptions of lava and debris that block rivers;
• Hydroelectric alluvial lake: A lake formed by the erosion of water and sedimentation.
According to the level of mineralization of lake water, it can be divided into freshwater lake, saltwater lake and salt lake:
• Freshwater lake: the lake mineralization degree is less than 1g/l for freshwater lakes;
• Saltwater lake: The salinity of lake water is more than 1g/l, and less than 35g/l is salt lake;
• Salt Lake: The salinity of lake water is more than 35g/l for salt lake.
According to the temperature of the lake, it can be divided into warm lake, warm lake and cold lake:
• Warm Lake: Warm lake is also called tropical lake. The temperature of the lake water is also above 4 °C in the coldest month, and there will be no freezing in the lake. Lakes such as Dianchi Lake and Bohai Sea in Yunnan are warm lakes;
• Wenhu: Wenhu is also known as the temperate lake. The hottest month’s water temperature can reach 20 ° C ~ 30 ° C or higher, the coldest month water temperature can be reduced to below 4 ° C. Most lakes in China belong to such lakes;
• Cold Lake: The cold lake is also called the polar lake. The water temperature of the lake is usually below 4 °C, even if the hottest month water temperature does not exceed 4 °C.
According to the replenishment conditions, it can be divided into active lakes and passive lakes:
• Active lake: There are lakes with rivers or streams, and the amount of water is mainly supplied by rivers. Most lakes in our country belong to this category;
• Passive lake: The lake basin is actively small, and its water source mainly relies on precipitation or replenishment of lakeside fissure water, such as the Baitoushan Tianchi.
According to the presence or absence of drainage, it can be divided into a closed lake and a lake:
• Closed Lake: A lake that flows from a lake without water flow. Most lakes in the inland lake area are such lakes. In Qinghai Lake, the largest lake in China, only the Buha River and other rivers flow into the lake, while the non-flowing water flows out of the lake. It is the largest closed lake in China;
• Through the lake: there are rivers that flow into the lake, and rivers that flow out of the lake. Most of the lakes in China’s outflow areas are such lakes.
In addition, according to the level of nutrition in the lake, it can be divided into: eutrophic lakes (such as the middle and lower reaches of the Yangtze River, and some lakes in the northeast are eutrophic lakes), medium-nutrient lakes and oligotrophic lake.