The lakes are bodies of water that are far from the sea and fill the hollows on the surface of the Earth. These depressions are called basins.
Lakes formed as a result of water runoff to low places. Lakes are replenished mainly due to rains and melting snow. Water enters the lake basin with streams, small and large rivers, underground sources and groundwater.
Lake pools are formed in several ways. Some lakes are the result of fracture and deformation of the earth’s crust. Lake Superior in North America is an example of such a lake.
Once formed, it is constantly evolving due to the external natural factors and the continuous effects of various internal processes. A large amount of sediment and biological debris carried by the river into the lake are deposited in the lake year after year. The lake basin gradually becomes shallow and becomes land, or gradually becomes a swamp with the development of aquatic plants along the coast; in dry climate conditions Inland lakes due to climate variability, reduced ice and snow melt water, groundwater level decline, etc., the amount of recharge water is not enough to compensate for evaporation loss, often causing the lake surface to shrink and dry up, or the accumulation of salt in the lake basin, the lake is increasingly salted, and eventually becomes a dry salt lake Some lakes are cut off due to export, and the lake water flows out and dry up. In addition, due to changes in the earth’s crust, climate change, and other factors that shape the lake, the lake will undergo a process of shrinking and expanding. No matter which way the lake naturally evolves, the result will eventually die out.
Sometimes lakes are created by volcanoes. Lava flow can block the flow of water into the valleys and form a pool. Sometimes the crater of an extinct volcano is filled with water. Crater Lake in southern Oregon is an example of such a lake.
Many lakes occupy pools formed by glacial erosion. All the Great Lakes, except Lake Superior and Lake Winnipeg in Canada are examples of lakes of glacial origin.
On the coasts, waves and coastal currents sometimes cut off narrow sea bays from the sea and, over time, form lakes from bays and estuaries. Sometimes the main course of the river itself can build a valley, depositing sediment (dirt and soil) during the spill. As a result, the valleys of tributaries are filled and form lakes.
In places where there is limestone under the soil, the groundwater dissolves and carries it away, creating large underground spaces from which the lakes basins are formed. Florida has many lakes of this type.
Lakes can also be created artificially. If a dam is built on the river, it will block the flow of water and a lake will form. Lake Mead appeared when the Hoover Dam was built on the Colorado River.