Dynamics of Natural Resource Use in the Selenga River Delta as a Result of Regulating the Level of Lake Baikal

A cartographic assessment of the dynamics of residential and agricultural natural resource use in the territory of the Selenga River delta based on topographic maps for different points in time for 1952‒2015 is presented. This period is characterized by the regulation of the level of Lake Baikal to maintain the operation of the Irkutsk hydroelectric power station and by a transformation of the system of natural resource use at the Selenga River delta and the lake shore. Based on vectorization of retrospective layers of topographic objects, a file geodatabase representing a cartographic reconstruction of natural resource use in 1952 was created in the ArcGIS software environment. This provides a retrospective snapshot of the natural state of coastal geosystems of the lake and makes it possible to establish physical and geographical features of past economic use of the territory. Based on the elevations and contours of the topographic basis at the scale of 1 : 50 000 based on a 1952 survey, a digital terrain model was compiled, as was a map of geomorphological structure of the study area. By combining the reconstruction with modern digital layers, the dynamics of waterlogging and flooding of the delta territory as a result of long-term level regulation of Lake Baikal were established, and a spatiotemporal assessment of the dynamics of individual objects of natural resource use was performed. By physical and geographical location within the estuary and by mode of traditional natural resource use, all settlements were divided into three groups: coastal, island, and estuarine. A register of settlements with a breakdown by area, number of households, and population size has been compiled. A cartographic assessment of the dynamics of the water surface area was used to identify waterlogged and flooded areas, stable areas, abandoned settlements, abandoned socioeconomic facilities, and abandoned arable land. Maps of the dynamics of the water surface and natural resource use were compiled.