Hydrological and hydrobotanic typology of the lake of North-Steppe Dnieper region

Abstract

This article is devoted to the typology of lakes of the North-Steppe Dnieper. In developing the typology of lakes, the parameters were taken into account: landscape location, hydro-chemical and hydro-biological characteristics and the degree of their anthropogenic transformation. The data presented are based on the processing of stationary and route research materials from 1998 to 2018 on the lakes of river valleys: Dnieper, Samara, and Orel. Hydrological indicators are analyzed according to the literature, cartographic and archival data of the Dneprodiprovodkhoz Institute and the Biology Research Institute of Oles Honchar Dnipropetrovsk National University. Floristic studies were carried out using general botanical methods of collection and herbarization, and in the study of typical aquatic flora - special hydro-botanical methods. Geo-botanical studies were carried out according to geo-botanical and special hydro-botanical methods. The article presents the hydrological and hydro-botanical features of the lakes of the valley of a large river (Dnieper) and medium rivers (Samara, Orel). Lakes are located exclusively in valley-terrace landscapes in the northern part of the steppe zone of Ukraine. Despite this, based on cartographic materials, we proposed zoning of the territory of the lakes of the North-Steppe Dnieper according to the criteria: their location in lake regions, in various landscapes and the degree of anthropogenic transformation. The following districts and subareas were identified: Dnieper Lake District (Dnieper floodplain lake subarea with slight flooding of the floodplain, Dnieper Lake subarea of floodplain terraces, Dievsky floodplain lake subarea); Samara Lake District (Lake Subarea of Samara Coniferous forest, Lake Subarea of Estuary part of Samara); Orel Lake District. Lakes are located in various physical and geographical conditions of the floodplain, arena and third saline terrace. The typology of the lakes of the North-Steppe Dnieper basin was developed on the basis of regionalization of the location of the lakes, distribution according to the ecological and topographic profile, hydrological, hydro-chemical regimes, degree and nature of overgrowing. 11 types of lakes are identified based on the above criteria. 6 types were identified for the valley of a large river: floodplain lakes (3 types) with a long-flow regime, lakes of the second (sandy) terrace (2 types) and highly mineralized lakes of the third (saline) terrace. 5 types were identified for the valleys of middle rivers: floodplain lakes (3 types) with an episodic short-burial regime, lakes of the second (sandy) terrace (low-mineralized) and excessively mineralized lakes of the third (saline) terrace.