Evaluation of water dissolved oxygen under climate change and its modeling in Bodrog River at Streda nad Bodrogom

Abstract

The oxygen is one of indicators of water quality that plays a crucial role in affecting the biological processes in surface water. In the context of the climate change, there are also changes in the oxygen regime of the water in the streams. The paper presents an evaluation of the changes in long-term data of the dissolved oxygen (DO), water temperature T w , biochemical oxygen demand (BOD) and chemical oxygen demand (COD), and flows ( Q ) in the Bodrog River at Streda nad Bodrogom, during the period of 1965–2021. The aim of the study is to detect whether significant trends occur in the time series of analyzed data. The first part of the paper dealt with the trend analyses of monthly and annual data. The results can be useful to quantify the possible threat to its balanced regime. The study shoved an increasing trend in the long-term trend of the DO and a decreasing trend in biochemical oxygen demand. The following section is focused on regression between selected components of the hydrosphere and modelling them. The ability to model the components of the hydrosphere is an essential part of water resource management.