Uvs Lake Basin, also called Uvs Nuur Basin or Ubs Nuur Basin (Mongolian: Увс нуурын хотгор), is a basin that does not drain into the ocean. It is located on the border between Mongolia and Tuva, a region in Russia. The basin is part of the Central Asian Internal Drainage Basin and is named after Uvs Lake (Uvs Nuur, Ubsu Nur), a large salty lake in the western part of its area. Uvs Lake is a shallow lake with an area of 3,350 square kilometers (1,290 square miles). The entire basin, which includes several smaller lakes, covers 70,000 square kilometers (27,000 square miles).

Uvs Lake Basin may also refer to Ubsunur Hollow (Russian: Убсунурская котловина, Ubsunorskaya Kotlovina), the western part of the drainage basin, or to over 10,000 square kilometers (3,900 square miles) of protected areas around the lake. The hollow is part of the Great Lakes Depression, a region with a surface area of more than 100,000 square kilometers (39,000 square miles). Most of the hollow and the drainage basin are located in the Khövsgöl, Zavkhan, and Uvs Provinces of northwestern Mongolia, as well as in the Mongun-Tayginsky, Ovyursky, Tes-Khemsky, and Erzinsky Districts of southern Tuva.

The basin is part of a landscape with raised areas and hollows found in the Tannu-Ola and Altai mountain regions. Here, the world’s northernmost desert meets the southernmost tundra in the Northern Hemisphere. An area of 10,560 square kilometers (4,080 square miles), with about three-fourths in Mongolia, was declared a Biosphere Reserve in 1997. A similar-sized area, partly overlapping with it, was named a UNESCO World Heritage Site in 2003. The Mongolian part of the lake and its surroundings were recognized as a Ramsar wetland in 2004.

Geography

The Tannu-Ola Mountains are the northern boundary of Ubsunur Hollow. Tere-Khol' Lake is the only freshwater lake in the basin. It is located on the Russian-Mongolian border, similar to Uvs Lake. The eastern part of the Uvs Lake drainage basin reaches the Sengilen Ridge in the Sayan Mountains to the north and extends to the Sangiin Dalai Lake basin to the east. The southern part of the hollow is next to the Khyargas Lake basin. The Khan Khökhii Mountains separate these basins in the Great Lakes Depression. Further east, the Bulnai Mountain Range forms the southern boundary of Uvs Lake's drainage basin. To the west of the Uvs Lake Basin is the endorheic basin of Üüreg Lake, which is surrounded by the Altai Mountains. The Tsagan-Shibetu Ridge partially separates the Uvs and Üüreg Lake basins. The southwestern part of the Uvs Lake Basin covers most of the Türgen Uul Range and includes the northeastern slopes of the Harhiraa Mountain.

Archaeology

Greenpeace reports that Ubsunur Hollow contains 40,000 archaeological sites from nomadic groups such as the Scythians, Turks, Huns, and other tribes. Many of the artifacts found there have not been studied yet. In Central Asia, this area has the greatest number of burial mounds, which make up about half of all its archaeological sites. Many of these mounds are older than the Egyptian pyramids. Thousands of rock carvings and stone sculptures from medieval settlements and Buddhist temples still remain.

Studies conducted between 2007 and 2008 at the Por-Bazhyn ruins, located on an island in the Russian part of Tere-Khol' Lake, suggest that the structure was built around the middle of the second half of the 8th century during the Uyghur Khaganate.

Population

The Ubsunur Hollow has a low population density. Few people live there, mostly the Tuvan people, who are nomadic, and cattle herders who live in yurts. There is little industry in the area, and the people rely on traditional ways of life, such as moving their herds of cattle from place to place. These practices have not harmed the environment much, allowing the ecosystem to stay mostly untouched by human activity. In both the Russian and Mongolian parts of the hollow, nomadic Tuvan herders live in yurts and make up almost all the population.

Flora and fauna

The Hollow is located on the border between Mongolia and Russia. It is where different types of environments meet. The area covers 10,688 km² (4,127 mi²). The land includes glaciers, deserts, alpine tundra, sub-alpine meadows, and large mountain taiga areas. Other features are forested steppes, treeless steppes, semi-arid deserts, and moving sand dunes. This area has a variety of natural habitats, where plant and animal life from the Euro-Siberian and Central Asian-Mongolian regions interact.

Because it lies between the Siberian and Central Asian-Mongolian regions, the Hollow has a high level of biodiversity for its location. Animals that live in both mountains and tundra, such as the Siberian roe deer and Altai snowcock, thrive here. The endangered snow leopard also lives in the area, along with taiga animals like the Caspian red deer, lynx, and wolverine. Animals found in the steppes include the Mongolian lark, demoiselle crane, and long-tailed Siberian squirrel. Desert animals include the bustard and midday gerbil. There are about 359 bird species in the region. Since the Hollow is a protected area, some species that are no longer found elsewhere have found a safe home here.

Conservation instruments

In 1993, Russia established the Ubsunur Hollow as the Ubsunurskaya Kotlovina State Nature Biosphere Reserve to protect its natural environment. In 1995, Greenpeace Russia proposed that Ubsunur Hollow, along with Mongolia, be recognized as a World Heritage Site. This proposal described the area as "one of the largest intact watersheds in Central Asia."

The Ubsunur Hollow Biosphere Reserve is a mountainous depression located on the border between Mongolia and the Republic of Tuva in Russia. It lies between the Tannu-Ola Mountains and the Altay Mountains, where the northernmost desert meets the southernmost tundra region.

In 1998, the Ubsunur Hollow Reserve in Tuva was officially designated as an international Biosphere Reserve. This step aimed to protect the wilderness of southern Siberia, which contains some of Russia's largest areas of untouched Siberian Pine and Siberian Fir forests.

In 1995, Ubsunur Hollow was nominated for inclusion in Russia’s second World Heritage Site (the first being the Virgin Komi Forests). The nomination described the area as "one of the largest intact watersheds in Central Asia" and noted the presence of up to 40,000 unexcavated burial mounds and other archaeological sites from ancient nomadic tribes, such as the Scythians, the Turks, and the Huns. This nomination involved cooperation between Russia, Mongolia, and the Tuva Republic, and it covered 75,000 square kilometers of forest, steppe, and cultural and natural heritage.

The Uvs Lake Basin World Heritage Site, designated as 769rev in 2003, includes the following areas:

• Mongun Taiga, Russia (50°12′N 90°12′E), located west of the Uvs Lake drainage basin.
• Ubsu-Nur, Russia (50°37′N 93°8′E), at the northeastern tip of Uvs Lake.
• Oroku-Shinaa, Russia (50°37′N 94°0′E), in the northern part of the zone around the Tes River, near the Mongolian border.
• Aryskannyg, Russia (50°40′N 94°44′E), east of the previous zone, partly within the Tannu-Ola Mountains.
• Jamaalyg, Russia (50°15′N 94°45′E), west of Erzin.
• Tsugeer els, Russia (50°5′N 95°15′E), in the northern part of Tere-Khol' Lake and its surrounding areas.
• Ular, Russia (50°32′N 5°38′E), in the western part of the Sengilen ridge.
• Tsagan shuvuut, Mongolia (50°19′N 91°9′E), part of the Tsagan-Shibetu ridge.
• Turgen, Mongolia (49°46′N 91°22′E), a mountain range south of Üüreg Lake, near Türgen, Uvs.
• Uvs Lake, Mongolia (50°20′N 92°53′E), covering most of the Uvs Lake zone.
• Altan els, Mongolia (49°50′N 5°0′E), a sand dune region south of Tere-Khol' Lake, including the Mongolian part of that lake.
• Tes River, Mongolia (50°28′N 93°45′E), the area between the river’s delta at Uvs Lake and the Russian border.