HYDROLOGICAL AND MORPHOLOGICAL CHARACTERISTICS OF PERMANENT WATER COURSES IN KOLOGRIVSKI FOREST NATURE RESERVE

Abstract

Introduction. Water courses found on the territory of Kologrivski Forest Nature Reserve are currently understudied; the research attempts carried out on the territory of the nature reserve are random and fragmented. The work aims to map the permanent water courses on the territory of the nature reserve in order to define the main water sheds, and study hydrological- morphological indicators of small rivers found on the territory of Kologrivski Forest Nature Reserve, followed by monitoring of their state. Materials and methods. The research was carried out from May to September 2014-2016 in Kologrivski and Manturovski sites of the reserve. The work uses field data obtained from the permanent observance sites, as well as from en-route inspection. All the measurements were carried out in triple replication. Results. On the territory of Kologrivski site of the nature reserve there are only small rivers, the right tributaries of the Unzha river. All the rivers feature different depth parts: the least depth is observed on the rifts with stone-sandy bottoms and current velocity up to 1.0 m/c. The river structure features the reaches of over 1.0 m depth and current velocity of 0.5 m/c, and also pits of over 1.5-2.0 m depth with a considerably slow current. All the territory of Manturovski site of the nature reserve belongs to Kastovo river basin – the left tributary of the first order of the Unzha. The largest water courses are the Kastovo and Ivanchikha rivers. The riverbeds of all the rivers are relatively straight, which is proved by curvature coefficient. The value of this coefficient for the Kastovo river within the nature reserve is 1.3, and in terms of the whole water course the coefficient is 1.4. The value of the curvature coefficient of the Ivanchikha river in 1.3 within the reserve and 1.2 in terms of the whole water course. Conclusions. As a result of the carried out research it was found out that the rivers ofKologrivski Forest Nature Reserve are characterized by the obvious spring flood, summer and autumn low water periods interrupted by floods and winter low water periods. The depth and width of rivers, as well as water consumption vary depending on the season and for short periods of time depending on precipitations. The rivers found in the Kologrivski site of the nature reserve are characterized by large scale overgrowing open low flow riverbank areas and exposed to a considerable zoogenic factor – beavers. The rivers of the Maturovski site of the nature reserve significantly differ from the rivers of Kologrivski site in terms of hydrological and morphological indicators.