Selenga

The Selenga is a large river.

It flows through Mongolia and Russia. It starts from two smaller rivers. Then it flows into Lake Baikal.

This river is very important to the lake. It brings almost half of the water there. The river forms a wide delta at the end. A delta is a place where the river meets the lake.

The weather can be very harsh. The river freezes from November to April. In the summer, it can flood after heavy rain. These floods can cover many areas.

Many animals live in the wet lands. You can find over 170 kinds of birds there. Some fish live only in this area too. It is a special home for them.

The river's name might mean "to swim." It is a very big part of the land.

The Selenga is a major river. It flows through Mongolia and Russia. It starts from two rivers called the Ider and the Delger. The river flows northeast. It joins the Orkhon River at Suhbaatar. Then it moves into Russia. It flows past the city of Ulan-Ude. Finally, it flows into Lake Baikal.

This river brings almost half of the water into Lake Baikal. At the end, it forms a wide delta. A delta is a place where a river spreads out. This area has many marshlands. It is a home for over 170 kinds of birds. Some fish, like the Siberian Baikal sturgeon, live only here.

The weather can be very harsh. The river freezes from November to April. The land has cold winters and warm summers. The river can also flood. Some floods are very big. In 1830, a large flood hit the city of Ulan-Ude. It destroyed many buildings. People had to move to higher ground. Today, humans use the river for mining and farming. These things can change the water quality.

The Selenga is a very important river in Asia. It flows through northern Mongolia and the Russian Republic of Buryatia. The river starts when two smaller rivers, the Ider and the Delger, meet. From there, it travels northeast and joins the Orkhon River at a place called Suhbaatar. After that, the river moves into Russia and flows toward the city of Ulan-Ude. Finally, it reaches its end by flowing into the huge Lake Baikal.

This river is a major part of the Arctic Ocean Basin. It brings almost half of all the river water into Lake Baikal. When the river reaches the lake, it spreads out into a wide area called a delta. This delta is shaped like a lobe and is about 40 km wide. The area is surrounded by many marshlands and wetlands.

Life in the Selenga basin follows the changing seasons. The weather is shaped by a strong wind system called the Siberian High. This causes very harsh winters with low temperatures. In January, the average temperature can drop to -19.4 degrees Celsius. The river stays frozen from November until April. During the summer, the weather becomes warm. In July, the average temperature is around 14 degrees Celsius. Most of the rain falls during the summer months. This extra water causes the river to flow much faster in the spring.

Sometimes, the river experiences very large floods. People group these floods by how much they affect the land. Some are called "catastrophic" because they cover the whole river basin. These big floods can happen three or four times every hundred years. Between the years 1730 and 1900, there were twenty-six documented floods. Out of those, three were catastrophic. One famous flood happened in 1830. It caused the river to burst its banks and flood many areas. The city of Verkhneudinsk, which is now Ulan-Ude, was flooded that year.

Archaeologists have found many interesting things near the river. In the late 1800s, people found stone tools from a very old culture. Later, studies in the 1940s uncovered 30 new sites in the region. One special site was called Ust-Kyakhta-3. Scientists found more than 40,000 stone artifacts there. They even found two small pieces of human teeth. These teeth helped scientists learn about the ancestors of Native Americans. They showed a link between those people and people from East Asia.

Many living things rely on the Selenga delta to survive. The wetlands are a protected site known as a Ramsar site. This area is a home for over 170 different species of birds. It is also where the Siberian Baikal sturgeon lives. This is a special fish that is found only in this area. However, humans have changed the river in some ways. Building power stations and using the water for mining can change the environment. These activities can make the water quality lower or change how the delta stays wet.

The Selenga is a vital river system in Asia. It flows through northern Mongolia and the Russian Republic of Buryatia. The river is a major part of the Arctic Ocean Basin. It serves as the primary source of water for Lake Baikal. In fact, the Selenga provides almost half of the total riverine inflow to the lake.

The river begins when two headwater tributaries meet. These are the Ider and the Delger mörön. The Delger flows from the Sangilen Mountains on the border of Mongolia and Tyva. The Ider starts in the Hangyn Mountains of central Mongolia. After these rivers converge, the Selenga moves northeast. It joins the Orkhon River at Suhbaatar. Then, the water flows north into Russia. It turns east toward Ulan-Ude before moving north to Tataurovo. Finally, it flows west into a wide delta. This delta is lobate in shape and is 40 km wide.

The climate of the Selenga basin is driven by the Siberian High. This is a powerful anti-cyclone, or a large system of high pressure. It forms in September and October. It disappears in April and May. This system creates harsh winters with very low temperatures. In January, the mean air temperature is -19.4 degrees Celsius. The river is covered in ice from November to April. Summers are warm, with a mean temperature of 14 degrees Celsius in July. The river is ice-free from May to October. During spring and early summer, snowmelt causes the maximum discharge. This means the river flows with its greatest volume.

Flooding is a regular feature of the Selenga. Scientists classify these floods by their impact. They use terms like "ordinary," "large," or "catastrophic." A catastrophic flood covers most of the river basin. These events can flood entire settlements and cause human casualties. They are estimated to occur three to four times per century. Between 1730 and 1900, there were twenty-six documented floods. Only three of these were catastrophic. The catastrophic floods occurred in 1830, 1869, and 1897. The 1830 flood was the first to be recorded in great detail. It caused the city of Verkhneudinsk, now Ulan-Ude, to flood.

Archaeology provides deep links to the past in this region. At the end of the 19th century, stone implement artifacts were found. These artifacts belonged to a Paleolithic culture. In 1928 and 1929, G. P. Sosnovskii led a study near Kiakhta. Later, from 1947 to 1958, A. P. Okladnikov directed a large expedition. This study uncovered 30 new sites. One important site was called Ust-Kyakhta-3. It was excavated in 1976 and 1978. Researchers found over 40,000 stone artifacts and many faunal remains. In 2012, scientists found two human tooth fragments at this site. A study in the journal Cell used these teeth. It established a link between Native Americans and ancestors in East Asia.

The Selenga delta is a highly significant ecological area. It is a Ramsar site, which is a protected wetland. The area is surrounded by marshlands. It is home to over 170 species of birds. It also provides a habitat for the Siberian Baikal sturgeon. This fish is an endemic species, meaning it is found nowhere else. However, human activities have caused environmental changes. Mining, agriculture, and wastewater dumping have lowered water quality. These are known as anthropogenic factors. Erosion and weathering also affect the water naturally.

River modifications have also changed the delta's environment. The Irkutsk Hydroelectric Power Station was completed in 1956. It sits on the Angara River. The station was built to raise the water level of the Angara. This was done to match the level of Lake Baikal. This causes water-level fluctuations in the lake. These changes can make parts of the Selenga Delta waterlogged. In 2015, Mongolia planned the Shuren Hydropower Plant Project. Environmental groups protested this plan. They feared it would disrupt river flow. They also worried about the breeding grounds of endemic fish in Lake Baikal.