The role ofenvironmental factors in the land use structure formation within the Vorona-Tsna interfluve during the recent 300 years
The results of studying 300 years of land use changes in the north-western part of the Privolzhskaya Upland are presented. A key plot with the area of 1950 km2 in the Kirsanov district of Tambov region in the northern forest-steppe zone was studied. Land cover map of the territory showing the locality types was compiled by automated and visual interpretation of Landsat 7 and 8 images and global DEM SRTM with account of field data, as well as the land use map showing settlements, arable lands, forests, meadows, bogs and erosion network. Characteristic feature of the region is widespread hydromorphic territories within the interfluve undrained and interfluve slowly-drained locality types, limiting the agricultural development. Large-scale materials of the General Land Survey were used for land use structure reconstruction as of the end of the 18th century; they show specific features of half-century long regional economic development. Correlation of land cover map with the recent and reconstructed land use maps revealed that in the 18th century arable lands were much more determined by land cover than nowadays. 300 years ago arable lands were more common for interfluves and gentle slopes with slight hydromorphism; nowadays these restrictions are partially leveled by agrotechnical practices. The percentage of arable lands within the interfluve undrained locality type increased from 50 to 70% and from 62 to 90% in the intermittent slowly-drained type. At the end of the 18th century forests and virgin steppes accounted for larger areas (as compared with nowadays) within the interfluve undrained, floodplain and terrace locality types, which are marginally suitable for agriculture.