О ТЕРМИНОЛОГИИ И КЛАССИФИКАЦИИ РАЗВЕТВЛЕНИЙ РУСЕЛ РАВНИННЫХ РЕК

Abstract

Braided river channels are very diverse both morphologically (in terms of the number and water content of channel branches, size and shape of islands, their position, ratios, evolution, etc.), and in the mode of channel changes. Nevertheless, both in Russian and foreign literature, when describing them, there are different points of view on terms and classifications that define them, which make it difficult to analyze types of braided channels and regimes of channel changes, possible reactions of channels to changes in factors due to too much generalization. The classification of Moscow State University is considered to be an exception. It is constantly being improved as new data are obtained based on scientific research. Braided channel reaches are formed at several structural levels – point, midchannel bars, channel (island), floodplain-channel and floodplain (split channels). Each higher level of braided channels includes channel types of the previous levels. The main channel patterns that determine channel regime of braided rivers are island-braided channels, along which there are distinguished morphological homogeneous reaches or single patterns of channels or certain channel branches. In turn, in island-braided channels each of their types has several varieties depending on the number and morphology of islands, channel stability, water content of channel branches and peculiarities of water and sediment runoff dispersion along them. Braided channel types and their varieties are characterized by certain values of the flow quasi-uniformity indicator of I.F. Karasev and special coefficients in hydrological and morphological relationships linking morphological parameters of channels with characteristics of determining factors. The article provides a detailed, most complete classification of braided channels and substantiates the use of terms and concepts that characterize each type or braided channel reaches and their elements.