Ecological assessment of water quality for different water uses: the upstream sub-basin of the Dnieper and Desna rivers

Abstract

Novelties of this study include a synthesis of water quality parameters for the upstream sub-basin of the Dnieper River. This upstream sub-basin includes the Desna River. The synthesis revels new insights on the sources of the water pollution and the status of the water quality for different purposes such as drinking, aquaculture and recreation. The main research objective was to identify the main sources of water pollution and how those sources could decrease the water quality. As a result of our analysis, we conclude the following. The levels of ammonium-nitrogen and nitrite-nitrogen in the Desna River (upstream sub-basin) are by 2-43 times and up to 53 times higher than the water quality thresholds, respectively. This poses a risk for recreational activities since too much nutrients often lead to blooms of harmful algae. We also find an increased level of biological oxygen demand in the river for drinking purposes. For aquaculture, decreased levels of dissolved oxygen are found. Climate change has an impact on water quality. For example, extreme floods caused by too much precipitation can bring pollutants to nearby waters. Monthly average temperature has increased by +2.7 degrees contributing to increased microbiological processes that could stimulate blooms of harmful algae. Main sources of water pollution are sewage discharges in cities, agricultural runoff and erosion activities after floods.