A lake is a patch of land in which water gathers and is surrounded by land on all sides. The lakes are fresh or salty. That is, its water ends in a river, it is fresh, but if it is closed and its life cycle is related to evaporation only, it is a salt lake. Lakes are formed for several reasons, including tectonic and volcanic activities and the movement of glaciers, while human activities, whether intentional or spontaneous, have caused the formation or destruction of many lakes.
Lakes are distributed all over the world, they are found in every continent of the globe, in their different environments and diversity, lakes are found in the desert, mountainous and plain areas and even near sea shores, and the continents of North America, Asia, and Africa contain 70% of the world’s lakes, so the number of lakes in America North and Alaska region to nearly three million lakes.
The lakes differ from each other in size, depth, height, or decrease from sea level, and the sources of lake water are rain, snow, and melting ice, in addition to groundwater seepage from the ground. The importance of lakes lies in mitigating the climate in the surrounding areas, and most of them are characterized by the abundance of mineral salts and fish, and lake water is used to generate electricity. A connection between the countries that overlook it and surround it.
Lakes and all pools of stagnant water are a natural environment distinct from river water in several respects, the first of which is the lack of sediments and vegetation. Then there are salt lakes, bitter, and some of them are fresh, and some of them are located at high altitudes and others at low levels, or even on the beach
The Largest Lake in the World
The largest lake in the world is the Caspian Lake, which is called a sea or a lake, so the Caspian Lake was named after the Iranian city of Qazvin. The reason for calling it the Caspian Sea is due to the nature of its salty waters.
The Caspian Lake is one of the seven seas that connected the continents of the ancient world together. It is Asia, Africa, and Europe, and the Caspian Lake separates the continent of Asia from Europe, and the Caspian Lake is the second largest oil-rich water body, with an area of about 370,000 km2, and the shores of the Caspian Lake are shared by five countries in certain proportions.
These proportions differ for several political and economic reasons related to its wealth and these countries are: Kazakhstan and Turkmenistan in the east, Azerbaijan in the west, Russia in the north, and Iran in the south.
As for the depth of the lake, it starts from ten meters on the northern Russian coast, and increases from 180 meters to 788 meters in the middle, while in In the south, near the Iranian coast, the depth reaches 960 meters, while its maximum depth was recorded in the south, which is 1023 meters. There is a large fish wealth in the Caspian Lake that includes specific types of fish such as fish caviar, which is extracted from its eggs, the valuable and rich caviar substance. About 78 species of fish live in the lake.
As for the rivers that flow into the Caspian Lake, they are numerous. Among the most important and greatest of them is the Volga River, from which most of the lake’s water comes and its source is Russia, and there is the Terek River that comes from Russia as well, the Ural River comes from Kazakhstan, and also flows into the lake, the Kura River comes from the Republic of Azerbaijan, and the White River and its source of water is Iran.
The World’s Largest Lakes
The largest lake in Australia is a salt lake called Lake Eyre, whereas the largest in Antarctica is a subglacial called Lake Vostok. In South America, there is Lake Titicaca, which is considered the highest navigable body of water on Earth at 3,812 meters above sea level.
The following is a list of the ten largest lakes in the world in terms of their total area:
Its area is 371,000 km2, and it contains approximately 78,200 km3 of water. Its average depth is 211 meters. The Caspian Sea overlooks Iran, Kazakhstan, Turkmenistan, Russia, and Azerbaijan, and the Volga, Ural, and Kura rivers flow into it.
The total area of 82,414 km2, it is the largest freshwater lake in the world, the second largest lake in terms of total area, and the third largest lake in terms of volume, and it is the largest lake in North America. The length of the lake is 563 km, while its width is 257 km. Its depth reaches 406 meters, and the reason for its formation is due to the glacial movements in that region.
Lake Victoria is the largest lake in Africa, the largest tropical lake in the world, and the second largest freshwater lake on Earth with an area of 69,485 km. it is nicknamed Queen Victoria, it derives water from the Kagera River, its basin covers a large area of the continent and is relatively shallow. Its average depth is 40 meters and its maximum depth does not exceed 84 meters.
Lake Victoria is surrounded by more than one country, Kenya, Uganda, and Tanzania, and contains 84 small islands. Lake Victoria is much younger than other lakes, as it dates back to about 400,000 years. Formed when west-flowing rivers were blocked by an upward crustal massif. It seems that the lake has undergone several changes over history, ranging from its current shallow level to a series of tinier lakes.
An area of 59,596 km2, one of the largest lakes in North America, with a length of 331 km, a width of 295 km, and an average depth of 59 meters. The lake was formed by glacial movements, and its water sources are the Saint Mary River and the Strait of Mackinac.
It has an area of 58,016 km2, is located in North America, and contains 4,918 km 3 of water. The length of the lake is 494 km, while its width is 190 km, and its deepest point is 282 meters, due to its formation due to glacial movements.
It has an area of 32,893 km2, and is the longest freshwater lake in the world, with a length of 677 km, while its width reaches a maximum of 50 km. The lake is located within the Great Rift West of the Rift Valley. It is the largest rift in Africa and the second-largest lake on the continent. It is the deepest lake in Africa and holds the largest volume of freshwater. The reason for its formation is due to terrestrial tectonic movements.
Its area is 31,500 km2, and contains 20% of the world’s fresh water. Its deepest point reaches 1642 meters, while its average depth is 744.4 meters. It was formed due to changes in the tectonic fault zone. It is considered the oldest lake on earth, as it is estimated to be at least 25 million years old.
Lake Baikal is a great lake located in southern Siberia in Russia. It is also the oldest lake in the world and was formed about 25 million years ago due to the movements of the earth’s crust. Since 1996, it has been included in the UNESCO World Heritage List. It is located in a rift groove, which is similar to Lake Tanganyika in Africa and contains more than 20% of the world’s non-frozen fresh water.
The large volume of the lake’s water affects the atmosphere of the neighboring regions. It is cold in summer from far away from the areas and the surface of the lake freezes in the period from January to May, and despite the mouth of 336 rivers in Lake Baikal, there is only one river that comes out of it, which is the Angara River.
Big Bear Lake
Its area is 31,080 km2, and it is the fourth largest lake in North America, and its length is 320 km, its width is 175 km, and its average depth is 71.7 meters. The source of its water is the Big Bear River. The lake is characterized by very low temperatures in Winter.
An area of 30,044 km2, an African lake located in eastern Africa. Lake Malawi is the third largest lake in Africa and the second deepest lake as well. Its depth reaches 706 meters, and its length is 579 km. The lake is located at an altitude of 500 meters above sea level. The reason for its formation is the separation of tectonic plates from each other.
Great Slave Lake
Its area is 28,930 km2, located in North America, and its depth reaches 614 meters. Its water sources are the Hay River and the Mackenzie River, and its water is frozen on most days of the year.
Great Pier Lake
Great Pier Lake is located south of the Arctic within the northwest region of Canada, and is the fourth largest lake in North America with approximately 31,000 km2. The lake extends for 320 kilometers, has a width of 175 kilometers, and a maximum depth of 446 meters, with an average of 71.7 meters.
There are 26 islands with a combined area of 759.3 kilometers. The Great Pier Lake derives its water from a river of the same name. It rises 186 meters above sea level and is famous for its unbearable coldness in winter.
Lake Malawi, about 30,000 km2, is located between the countries of Tanzania, Mozambique and Malawi, and besides being ranked ninth in the world, it is the third largest and second deepest lake in the African continent. Lake Malawi has a maximum depth of 706 meters, a length of 579 kilometers, and an average depth of 292 meters, and its main tributary is the Ruhuhu River.
The lake, which was formed at an altitude of about 500 meters above sea level as a result of the separation of tectonic plates, is famous for being the home of the largest number of fish species in the world, including about a thousand species of crustaceans.
Great Slave Lake
It is approximately 29,000 km2. Great Slave Lake is the deepest lake in North America. With a depth of 614 meters, it is the second largest lake in northwest Canada. The length of the lake is 480 km, its width ranges from 19 to 109 km, and it covers an area of 28,930 km. Its main tributary of water is the Hai River and flows into the Mackenzie River. Due to its location in the far north, it is known that its waters are frozen in most parts of the year.
Types of Lakes
- Lakes are usually divided by limnology into three sections:
- Littoral zone, is a sloping area close to the land.
- Profundal zone (deep-water) as little sunlight can penetrate through.
- Photic zone (open-water), as sunlight can easily penetrate through.
There are several types of lakes according to their nutritional content or the nature of their composition, these types include:
- There are three basic types of lakes according to their nutritional content:
- eutrophic lakes
- oligotrophic lakes
- dystrophic lakes
- Lakes can also be classified into:
- freshwater lakes
- saltwater lakes
- temporary lakes
- permanent lakes
- Lakes formed by the movement of the earth:
- tectonic lakes
- rift valley lakes
- Lakes formed by ice
- mountain lakes
- hollow rock lakes
- lakes formed by earthen dams of valleys
- Lakes formed by volcanic activity.
- Lakes formed by erosion.
- Lakes formed by sediments
- lakes formed by river sediments
- lakes formed by marine sediments
- dam lakes
- man-made lake
They are bodies of water rich in nutrients, and in which many creatures live from birds to reptiles to mammals to plankton, and the depth of this type of lake usually ranges from one to several feet, and the spread of disturbing plants in this type of lake varies according to its breadth, depth and conditions surrounding environment.
This type of lake is limited in terms of the nutrients contained in it, and the shape of these lakes is more attractive to the eye, due to the lack of leaves and plants that grow above them.
They are also characterized by low sources of nutrition, and their water is often brown due to floating soil and abundant clay particles.
Permanent and Temporary Lakes
Temporary lakes are lakes that fill small depressions in the ground after heavy rainfall, and evaporation of the waters of these lakes occurs. Examples of these lakes are small lakes that form in deserts. Permanent lakes are deep and hold more water than can be evaporated. An example of these lakes is the East African Rift Lakes.
Most of the lakes in the world are freshwater lakes, fed by rivers, an example of fresh lakes is the Great Lakes of North America.
Water is drained to saline lakes from groundwater that contains a higher salt content than usual or does not have a natural outlet from freshwater, and due to intense evaporation, the balance between the freshwater acquired from rivers and the saltwater in the lake is lost, and its water becomes salty. Examples of salt lakes are the Aral Sea and the Dead Sea, which contains a salt content of 250 parts per thousand, and salt lakes are one of the components of desert environments.
Tectonic lakes are formed as a result of a slight distortion or distortion in the earth’s crust. The so-called tectonic depressions occur, and these depressions lead to the formation of lakes of enormous sizes and depths. An example of tectonic lakes is the Caspian Sea.
Rift Valley Lakes
A rift valley is formed by the movement of two masses of land from each other, and this causes the mass between them to slide downwards. An example of the Rift Valley is Lake Albert, and the Dead Sea is also one of the Rift Valley lakes.
Hollow Rock Lakes
The advance and retreat of glaciers can scrape depressions at the surface where water accumulates, and these lakes are common in Scandinavia, Patagonia, Siberia, and Canada.
Lakes Formed by Volcanic Activity
During a volcanic eruption, the top of the cone may erupt, leaving behind a natural hollow area called a crater, and that area expands with time to be an area called a caldera, and when it rains heavily, a lake called a caldera is formed.
The Difference between a Lake and a Pond
An ecosystem consists of all the non-living elements and living species in a specific local environment. The components of most ecosystems include water, air, sunlight, soil, plants, microorganisms, insects, and animals. Ecosystems may be terrestrial, i.e. on land or aquatic, and the sizes of ecosystems vary. It could be just a small pond or a vast expanse of desert.
Both ponds and lakes represent areas of interior water that are mostly fresh and contain living organisms, and at first, they look very similar, but the difference between them is due to depth and surface area.
The lake is deeper than the pond. The area of the lake is usually greater than the area of the pond. The pond and lake water comes from external sources such as wells or streams. In addition, all the pond’s water is located in the photovoltaic zone, which means that it is shallow enough to allow the sun’s rays to reach its bottom, and the lake contains deeper areas that may not reach the sun’s rays.
Because of the light reaching the bottom of the ponds, many plants of the components of the aquatic ecosystem grow at the bottom of the pond and on its surface, while the lakes grow fewer plants. Waves in ponds are much less than in lakes. The water temperature throughout the pond is approximately equal, while some lakes can have some differences in water temperature depending on the depth.
A lake can affect the surrounding environment by affecting the climate, while a pond is always affected by the climate of the surrounding environment. Both ponds and lakes are types of aquatic ecosystems and they both lie on land and are not part of the ocean.
Types of Ponds
Spring Ponds (ephemeral)
These ponds are formed in the spring by melting snow and increased rainfall, and usually, dry up within a few months, and on the rum of the short life of these ponds, a group of wetland types depends on them, such as salamanders, frogs, and some herbs, and mammals and birds use them for drinking as well as To catch food that alba is scarce after winter is over.
They are formed as a result of the retreat of glaciers, which leave behind water-filled depressions, where part of the glacier separates and becomes an integral part of the land and with the gradual melting of the ice forms a pond rich in glacial sediments, often very old boiler basins, and in some cases the depth of these Ponds over 100 feet. Most boiler ponds are found in open areas near mountains, savannas, and prairie areas.
Ponds Fed by Springs
The ponds fed by the springs are very clean and rich in minerals, as clean water is constantly pumped to them from the ground during the flow of groundwater to the surface. When researching the aquatic ecosystems of ponds fed by springs, we find a wide range of species such as salamanders, dragonflies and various plant species. However, the species that need clean water, yet we rarely find life at the bottom of the pond itself because cold spring water reaches the bottom.
Mountain pools are formed around the mountains, usually at the base of the mountain itself or within its cracks. Mountain pools are formed from melting snow, runoff, and changing rocks, and are only found in mountainous areas.
Meadows Flow Ponds
Meadow ponds form alongside streams, provide valuable water and food sources for various animals, usually have muddy bottoms, and species such as salmon, wandering ungulates such as elk, a great variety of minute and large invertebrates, birds, and anything else in the system depend on them. The ecological sequence of grasslands, and may exhibit forms of the ecological succession of plants in that environment.
Human used ponds because they are small in size compared to lakes for a variety of purposes such as:
- Fish breeding
- Flood Control
- Man-made promotional items in zoos, amusement parks and palaces
- Preserving the water, as people used it to maintain an adequate amount of rain water reserves and to preserve it from waste and loss