Manifestation of tectonic and neotectonic structures in morphodynamic types of river channels (on the example of the Kolva river, Perm Urals and Pre-Urals)

The purpose of the study was to establish the relationship between the types of morphodynamic river channel and tectonic and neotectonic structures of different sizes and orders. The typification of the channel and its elementary forms was carried out in accordance with the classification scheme of Moscow State University. Google Earth Pro and Yandex Maps resources were used in the process of deciphering satellite materials and obtaining quantitative information (relief height, length of a river section). Geologic data was analyzed using the materials from the tectonic zoning of the Perm region, maps of neotectonic block structures and geodynamically active zones and seismicity. It has been established that the set of morphological varieties of meanders and braided channels in the structure of morphodynamic types in the upstream, midstream and downstream of the Kolva River differs from each other. Thirteen sections with varying channel types were identified on the Kolva River. The morphometric characteristics of the elements of the channel and the bottom of the river valley were used as identification criteria. These are the size of meanders, the length of straight sections of the channel, the width of the floodplain, and others. The presence or absence of a connection between the development of morphodynamic river channel types and morphological varieties of meanders and braided channels with the geostructural plan of the study area is considered by identifying the spatial correspondence of the locations of morphodynamic sections of the channel and geological structures of different scales and different hierarchical levels. In zones of changing neotectonic activity between adjacent areas, a change in the leading varieties of meanders and/or braided channels was recorded. Areas of a relatively straight channel are replaced by a meandering channel within the forward folds of the Urals. Varieties of meanders are represented mainly by active forms (segmental, forced). In the Pre-Ural trough, the reaction of channel processes to changes in the activity of neotectonic and modern movements was most pronounced within areas in which neotectonic structures are complicated by structures of a lower order.