Cherny Iyus

Cherny Iyus   is a mountain river in the northern part of Khakassia, Russia. It flows through the territories of the Shirinsky and Ordzhonikidze districts. Merging with the Bely Iyus it forms the Chulym River, the right tributary of the Ob.

Etymology
Also known as Hara-Üüs, Chërnyy Iyus, Chyorny Iyus, Chyorny Yus, Czernoi Ijus, Tchernoi Yious Russian name Чёрный Июс comes from local name Хара-Ӱӱс. Occurs in the pre-reform spelling Старой Iюсъ, and in the Khakass spelling  Кара-Ӱс.

An analysis of the toponymy of the Khakass-Minusinsk basin and the areas adjacent to it indicates that, along with the stratified Turkic toponyms of a later origin, toponyms clarified from the Ugric and Samoyedic languages dominated here.

The inhabitants of the Urals call the rivers flowing to the West White rivers; those that flow to the East or to Siberia, in Black rivers.

Description
Cherny Iyus belongs to the middle size rivers of Khakassia. The length of the river is 178 km long. Drainage basin of Cherny Iyus is 4290 km2.

Source of Cherny Iyus are the tarn lakes (Chernoye (Black) 1310 m:, Vysokoye (High) 1310 m, Dolgoye (Long) 1210 m, Verkhneye (Upper) 1220 m, Lake #80747788 1150 m Lake #583652017 1260 m )  and Glaciers #80747767, #80747752,  #80747704  on the eastern slope of Mount Bely Golets 1594 m in Kuznetsk Alatau.

Mouth of Cherny Iyus is river Chulym where Cherny Iyus and Bely Iyus join together. The height of the source is 1340 m, the height of the mouth is about 300 m.

The swampiness of the river basin is about 5%, the forest cover is 75%. In the annual course of the water regime, spring floods are distinguished (starting from the second or third decade of April, lasting up to a month), summer-autumn (lasting 2–4 months) and winter (from late October to early November) base flow. Summer-autumn base flow is repeatedly interrupted by rain pickups. The total spring-summer runoff is 80–85%. In winter, icing is observed with the release of water onto the ice. The average annual water consumption is 43.1 m3/s according to Stream gauging station in Sarala about 55 км from Source of the Cherny Iyus river. The waters of the rivers of mountainous regions, in the nutrition of which high-mountain snows and glaciers play a significant role, are characterized by a bicarbonate-calcium composition and very low (less than 0.1 g/dm³) mineralization.

Upstream (before the confluence of the Bolshoi Injul river) the river has a sublatitudinal direction of the valley with a typical mountainous nature of the watercourse. The valley is narrow, its width is up to 100 m - 300 m m, the height of the sides is up to 700 m, winding, has a significant longitudinal slope (0.013). The speed of the river flow is 1.2 m3/s - 2 m3/s m / s, channel width 20 m - 50 m, depth 0.8 m - 1.4 m. In this part of the basin, the river has many tributaries, the main of which are: on the left - the rivers Podsnezhnaya, Demidovka, Izbass with Uspenka. Nameless and Bobrova, Berezovaya, Injul; on the right - the rivers Poltavka, Sargaya, Krutoy, Karagainsky Injul, Small Black Iyus, Big Injul. Tributaries on the right are smaller and shorter from 6 km to 25 km than the left tributaries, which usually have their own well-developed basins.

After the confluence of the rivers Big and Small Inzhul, Kolchakovsky stream, the general direction the river flow changes sharply to submeridional, the width of the valley increases to 3 km-5 km (near the village of Chebaki and the village of Gaidarovsk). A single channel is divided into many channels, branches, the largest of which reach a width of 25 m - 40 m at a depth of up to 2 m, a longitudinal slope decreases to 0.0028. Further, before the confluence of the Sarala River, the valley narrows to 1 km - 1.5 km, but her character remains the same. On this section of the valley, they flow into the Black Iyus River: on the left - small rivers and streams Systygchul, Stuchul, Blinzhul, Kerebezhik, Tranzhul, Sektinsky, Pelageikin, Chesnokov; on the right - Belaya Pilnya, Martachul, Izekiyula. After the confluence of the river Sarala Black Iyus again changes its direction to sublatitudinal, the width of the valley increases to 1.5 km - 2 km, it also has many ducts, branches, small lakes and oxbow lakes, the longitudinal slope decreases to 0.0015. The river has only one tributary here on the left - the river Pechische

In its upper reaches, the river flows in limestones, but in general its left-bank mountains consist of granites and syenites, and the right-bank ones consist of clay shales, limestones and sandstones. Many gold-bearing rivers flow into the river.

Kyzyl people live in the valley of the Black Ius River.

Tributaries
(km from mouth)


 * 6 km: Pechesche (Kostinsky Pechische) (left)
 * Ustinkin (left)
 * 52 km: Pravaya Sarala (Sarala) (left)
 * 84 km: unnamed watercourse
 * Kokchen (left)
 * Chesnokov (left)
 * Pelageiken (left)
 * 93 km: Tranjul
 * 104 km: Cheryomushka (Sastygchul, Sistychul) (left)
 * 115 km: Small Inzhul (Rozhdestvenskiy)
 * Bolshoi Injul (Big Injul)
 * 120 km: Maly Cherny Iyus (Small Black Iyus)
 * 128 km: Inzhul (left)
 * 140 km: Izbass (left)
 * 155 km: unnamed watercourse
 * Nizhnyaya Demidovka (left)
 * Demidovka (left)
 * Poltavka (right)

Water registry data
According to the State Water Register of Russia, it belongs to the Upper Ob Basin District, the water management section of the Chulym river from the city of Achinsk to the water metering station in the village of Zyryanskoye, the river sub-basin of the Chulym river. The river basin of the river is the (Upper) Ob to the confluence of the Irtysh.

History
The earliest scientific and cartographically accurate description of  Cherny Iyus river  region  was done by German doctor and naturalist Daniel Gottlieb Messerschmidt in the expedition on the territory of the Yenisei  Siberia 1720–1727 who was personally accepted into the Russian service by Peter the Great.

In it was described by German historian and geographer Müller Gerhard Friedrich in his notes during Great Northern Expedition1733 -1743, at that time upper part of Chulym also was called Iyus.

In 1812 it become famous for the richest placers of gold and its development of gold mining. Gold placers began to be developed 1832,  507 poods of gold was mined in the Cherny Iyus river basin from 1834 and by 1900.

In 1835 it was also mentioned in "Description of the Yeniseisk Governorate" by the first governor of Yeniseysk Governorate in Krasnoyarsk Alexander Petrovich Stepanov in his work awarded the half Demidov Prize by the scientific community in the "Statistics" section and Nicholas I awarded Stepanov a diamond ring for this book.

In 1881 it was described by Pestov and noted that Chulym Tatar population was living around area between Cherny Iyus and Bely Iyus.

In 1890 was described by Nikolaii Vasilʹevich Latkin  in the Brockhaus and Efron Encyclopaedic Dictionary  and beside gold mining also mentioning copper mine and a factory in the tributary of the Cherny Iyus, the Pechishche River. The river basin region was known for  monuments of ferrous metallurgy.

in 1967, a teacher at the Novokuznetsk Pedagogical Institute, Shpin discovered the first glacier in the upper reaches of the Black Ius River with an area of 0.2 km2, the results of the following expeditions of 1968–1975 a Catalog of glaciers was compiled, aerial photographs were analyzed and a whole glacial system was discovered, consisting of cirque, hanging and slope glaciers with a predominantly northeastern exposure.

Fauna
Moschus moschiferus listed in Red Data Book of Khakassia.