| Orlovka (Mamyn) Орловка / Мамын | |
|---|---|
_USSR_map_NN_52-11_Mayskiy.jpg) Map section of the confluence of the Mamyn (Orlovka) and the Selemdzha | |
  Mouth location inAmur Oblast, Russia | |
| Location | |
| Country | Russia |
| Physical characteristics | |
| Source | |
| • location | Dzhagdy Range |
| • coordinates | 53°04′36″N129°33′05″E / 53.07667°N 129.55139°E /53.07667; 129.55139 |
| • elevation | 268 m (879 ft) |
| Mouth | Selemdzha |
• coordinates | 52°05′01″N129°25′40″E / 52.08361°N 129.42778°E /52.08361; 129.42778 |
• elevation | 179 m (587 ft) |
| Length | 208 km (129 mi) |
| Basin size | 11,300 km2 (4,400 sq mi) |
| Discharge | |
| • average | 160 m3/s (5,700 cu ft/s) |
| Basin features | |
| Progression | Selemdzha →Zeya→Amur→Sea of Okhotsk |
TheOrlovka (Russian:Орловка), also known asMamyn (Russian:Мамын),[1] is a river inMazanovsky District,Amur Oblast,Russia. It is the 4th longest tributary of theSelemdzha after theByssa, with a length of 208 kilometres (129 mi)[2] and the second in drainage basin area, with 11,300 square kilometres (4,400 sq mi).[1]
The river basin includes the Garinskoyeiron ore deposit, one of the largest in the Russian Far East,[3] as well asgold prospecting areas.[4] The only settlement in the river basin isOktyabrsky, located by riverGar, the main tributary.[2] In the past there had been other settlements by the river, such as theSlava collective farm on the left bank near the mouth, but they were abandoned.[5]
The originalTungusic name of the river was replaced in 1972 under theUSSR administration at thetime of the renaming of geographical sites in the Russian Far East.[6] The name "Orlovka" honorsWarrant Officer Orlov, who visited the area in 1847 to trade with the localEvenks on behalf of theRussian-American Company.[7][2]
In 1999, the Orlovsky Zakaznik (Орловский заказник), a 121,456 ha (300,120 acres)protected area, was established in the lower basin of the river. The fauna of the state reserve includeselk,red deer,roe deer, wild boar, bear, sable, mink, lynx, otter,Oriental stork,hooded crane,mandarin duck, white-tailed eagle, osprey andgreater spotted eagle.[8]
The Orlovka is a righttributary of the Selemdzha. It has its origin in the southern slopes of theDzhagdy Range at the confluence of the 44 km (27 mi) long Left Orlovka (Left Mamyn) and 74 km (46 mi) long Right Orlovka (Right Mamyn) rivers. In its upper reaches the Orlovka flows with relatively moderate speed as a mountain river with somerapids among pebbles and boulders. After its confluence with theGar, it progresses slowly southwards in a widefloodplain,meandering through swampland dotted with small lakes.[2][9] It divides into branches near the area where it joins the banks of the Selemdzha, 78 kilometres (48 mi) from its mouth in the Zeya. The mouths of the Orlovka are nearAbaykan, downstream from the mouth of theNora (river).[2][10]
The river basin is almost entirely within theAmur-Zeya Plateau. The climate is harsh, with long and very cold winters. In January, the average temperature sinks to −31.1 °C (−24.0 °F). Summers are short, with an average temperature in July of 20 °C (68 °F). The annual precipitation in the basin ranges between 550 millimetres (22 in) and 580 millimetres (23 in).[2]
There is patchy distribution ofpermafrost in the basin, the layer being closest to the surface in river wetlands withmoss cover. The river freezes in mid October and stays under ice until the end of April.[2]
The river has many tributaries, the longest one being the 208 km (129 mi)([dubious –discuss]) long Gar with a basin size of 3,870 square kilometres (1,490 sq mi), which joins the right bank of the Orlovka in its lower course.[11] Other important ones are the 89 km (55 mi) long Inkan, the 68 km (42 mi) long Byki, the 71 km (44 mi) long Sartama and the 64 km (40 mi) long Ushmyn from the right, and the 76 km (47 mi) long Sokhatinaya and the 56 km (35 mi) long Armiya from the left.[2]
