Dissolved oxygen in rivers: Concepts and measuring techniques

Abstract

This chapter presents the basic concepts of methods and techniques used in the measurement of dissolved oxygen in flowing water. Based on field tests carried out on the Narew, S´ wider and Vistula Rivers, sensor performance was analysed. The results show that the comparability of sensors depends not only on their accuracy, but also on the hydrological conditions under measurement, as well as the duration of measurement and sensor location. For diel measurement, the time delay between the maximum temperature and minimum oxygen concentration is acknowledged and briefly discussed. Moreover, in contrast to other studies, the main attention has been focused on abiotic factors that affect oxygen conditions in rivers. Finally, the key research challenges are highlighted.