Influence of Cascading River–Lake Systems on the Dynamics of Nutrient Circulation in Catchment Areas

Abstract

Matter circulates in nature constantly, between terrestrial and aquatic ecosystems, exchanging elements between the biotope and biocenosis. Each aquatic ecosystem is resistant to a specific load, above which its degradation occurs. It seems that the resistance of cascade reservoirs is higher than that of drainless reservoirs. Changes taking place in one part of the river–lake system cause disturbances in the dynamics of nutrient circulation in another. Rivers supplying water to lakes in a river–lake system have a significant impact on their water quality and on the spatial distribution of pollutants in their bottom sediments and in macrophytes located along their route. The assimilation capabilities of cascading river–lake systems result from their reaction to environmental stressors in the form of anthropogenic factors. They act as natural biogeochemical barriers, limiting the transport of pollutants outside ecosystems. In-depth knowledge of the processes taking place in the river–lake systems enables analyses aimed at forecasting the directions and intensity of these changes and predicting the response of the river–lake systems to the loads from the catchment areas. The collected information makes it possible to create simulations of processes occurring in river–lake systems, which allows for effective action to be taken to protect surface waters. This article provides an overview of available literature, presenting significant research results which enable an understanding of these processes.