Оренбургский край

Geographically, the territory of the Orenburg region covers the south-eastern margin of the East European Plain, the southern tip of the Urals and the southern Trans-Urals. The Orenburg region's climate is characterized by well-defined continentality due to its significant remote location from the oceans. The index of continentality is the high oscillation amplitude of average air temperature between winter (January) and summer (July), which reaches 34-38°C in the Orenburg region.

The continental climate is also characterized by the lack of atmospheric precipitation, the annual amount of which ranges from 450 mm in the north-west to 260 mm in the south and south-east of the region. About 60-70% of the annual precipitation falls on a warm season. The low moisture supply of the Orenburg steppes often leads to drought. The snow cover duration is from 135 days in the south to 154 days in the north. The frost line varies from 70 cm in the north-west to 1 m in the east.

The percentage of different types of lands in the region is the following: 49% of arable lands, 38% of forage lands, 5% of forests, 8% of other lands. The region's territory consists of landscapes of the forest-steppe belt of Russia, the steppes of the Trans-Volga and Turgay, the sylvan low-hill terrain of the Southern Urals, the mixed pine and birch forest-steppe of Western Siberia.

The area is characterized by a rather significant density of the river and gully network. The Ural River (the largest river of the region) is the transit one, the most of its flow is formed due to the Sakmara, its main tributary. Two large rivers Sakmara and Ilek originate in the Republic of Bashkortostan and Kazakhstan, respectively, and flow into the Ural already within the region. Most of the other significant rivers (the Samara, the Chagan, the Bolshoi and Malyi Kinel, the Dyoma, the Tobol) have sources and a significant part of the water-collecting area in the region, but its lower courses go beyond the borders of the region. The stream flow of medium and minor rivers is completely formed on the territory of the region. Almost all rivers belong to the Caspian Sea basin. Most of the river water is fed of the atmospheric precipitation (60-95%).

The surface waters form the river systems of the Ural (63% of the territory), the Volga (31%), the Tobol (2%) basins and the endorheic basin of the Svetlinsky Lakes in the east of the region. The most significant rivers are the Ural, 2428 km long (1164 km within the region with a basin area of ​​about 78 thousand km2), Sakmara (798 km), Ilek (623 km), Samara (594 km).

A significant area (about 5 th. km2) in the east is occupied by the endorheic basin of the lakes Shalkar-Yega-Kara, Zhetykol, Ayke. Lake Shalkar-Yega-Kara is the largest natural water body with the area of ​​9600 hectares and a coastline of 96 km. The area of lake Zhetykol is more than 3000 hectares. Ancient lakes are widespread in the floodplains of large rivers.

Artificial reservoirs are an integral part of the region's water resources and its water management. There are more than 312 ponds and reservoirs in the region with the total area of ​​about 15,600 hectares. This area does not include the water surface of the Iriklinskoye reservoir, the largest artificial reservoir in the region. The largest artificial reservoirs based on storage volume are the following: Iriklinskoye (3257 mln. m3), Krasnochabanskoye (54,6), Chernovskoye (52,7), Kumakskoye (48,0), Elshanskoye (23,6), Ushkottinskoye (10,0 mln. m3).

The region is located mainly in the steppe zone and the total forest area is 620 thousand hectares (5% of the region's territory). The highest forest cover is in Buzuluksky (22%) and Northern (19%) districts, the lowest forest cover is in Akbulaksky (0.5%) and Dombarovsky (0.4%) districts.

More than 2,500 deposits of 75 types of minerals have been explored in the bowels of the region. The most important for the Orenburg region are deposits of gas, oil, copper-pyrite ores and halite. The western and central parts of the region have significant reserves of oil and gas, building materials made out of sedimentary rocks. In the east of the region there are deposits of metallic minerals: copper, gold, chromites, nickel, iron, manganese ores, molybdenum. There are also non-metallic deposits, including chrysotile asbestos, kaolin, facing marbles, ornamental jaspers, rock crystal, high-quality flux limestones and quartzites, high-strength building stone, refractory and infusible clays, sands and sand and gravel resources, brick and expanded clay feedstocks, bentonites.