Mapping Arable Lands in Agricultural Landscapes of Volgograd Region According to Remote Sensing Data

Abstract

Currently, more and more attention is being paid to the development of technologies for the satellite monitoring of land use and the state of agricultural landscapes. The lack of up-to-date information about the boundaries of individual agricultural fields does not allow us to fully assess the state of arable land and take them into account. The available statistical sources have discrepancies and do not have information about the spatial distribution of used and unused agricultural fields. The purpose of this work is to establish the spatial distribution of cultivated and uncultivated arable lands of the Volgograd region according to remote sensing data. This paper presents the results of mapping the actual boundaries of arable lands of the Volgograd region as of 2021. High-resolution Sentinel-2 and Google Earth PRO data in the geographic information program are used to decrypt arable land. As a result, 6.05 million ha of arable land are mapped. The data are compared with official statistics for 2021, and an excess of 12% is noted in comparison with the results of decryption. It is noted that, over the past 20 years, according to statistical data, the areas of arable land and deposits have practically not changed. When comparing the decryption results with the data on arable lands of the Vega service, a difference of 4% was noted, which is quite high accuracy. According to the All-Russian Agricultural Census of 2016, the area of arable land used was exceeded by 8%. According to the SRTM digital terrain model, morphometric parameters of arable land were calculated throughout the region. It is determined that agricultural fields are located mainly on the slopes of the western exposure (37%), which is due to the predominance of the general slope of the relief to the west. Most (78%) of the field areas are on slopes with a steepness of up to 1°, and about 2% occupy areas of more than 3°. Water erosion is noted on steep slopes. The smoothest relief in the Volga region is on the territory of the Caspian lowland. Using remote methods, the assessment of the areas of fallow lands was carried out: about 960 000 ha. According to various sources, from 4800 to 891 000 ha of unused arable land are noted. The resulting geoinformation basis will make it possible to fully account for and assess the condition of cultivated and uncultivated arable lands, as well as develop projects for the rational use of land resources to increase yields and prevent the degradation of agricultural landscapes.