The quantity of sand fraction sediment in reservoirs as the basis of an assessment of the bedload transport from a reservoir catchment

Abstract

A knowledge of the quantity of the sand fraction in the sediments deposited in reservoirs makes it easier to determine the bedload transport, which is a rarely measured parameter. The current study discusses the results of investigations into the siltation and physical properties of sediment in two small reservoirs located in the southeastern part of Poland. Also, the quantity of the bedload sand fraction was estimated. The estimation of the reservoir capacity loss after t years of operation was based on hydroacoustic measurements. The sediment density, organic matter content, and granulometric composition were evaluated by means of investigations and analyses of bottom sediment core samples. The interpolation of the parameters describing the sediment properties was done using the Kriging method. The analyses indicate that 10.80 thousand m3 of sediment were deposited into the Zalew Kielecki Reservoir in the years 2004–2015. Their overall mass was 7320 t, of which sand fraction sediments constituted 39.7%. Between the years 2004 and 2014, the Umer Reservoir retained 11.79 thousand m3 of sediment having a mass of 7200 t, of which sand fraction constituted 34.6%.