Changes in a river’s regime of a watercourse after a small water reservoir construction

Abstract

The paper deals with the analysis of a river’s regime of a small watercourse and the evaluation of its changes after the construction of a small water reservoir. The aim of the work was to analyse 12 years of flow rate measurements at two profiles of a small watercourse, between which a small water reservoir was built, in the middle of the period of the measurements. The analysis uses traditional characteristics (average flow rate, discharge volume), as well as modern indices from applied hydrology (Richards-Baker flashiness index, hydrogram pulse analysis), which study the variability of the flow rate in hourly and daily intervals. The evaluation showed that at the average flow rate, the effect of the water reservoir was the smoothening of the peak flow rates and prolonging the duration of the discharge waves. At higher flow rates, the water reservoir causes a delay in the culmination and in terms of discharge balance causes a decreased discharge volume, in particular during the vegetation period.