The many years' measurements of silting the small water reservoir, closing the cachment covered loesses soils, allowed on the change qualification of the silt-ing degree during operation. In this work was compared the archival data from the measurements of silting the water reservoir in Zesławice, executed in the pe-riod before his desilting, with the results of measurements executed after desilting and building the side assistant reservoir. Water reservoirs in Zesławice are characterize the high intensity of silting. The Annual mean of silting ratio of res-ervoirs carries out: 3,0 % – the main reservoir before desilting, 1,87 % – the main reservoir after desilting and 1,00 % – the side assistant reservoir. Disposing the volume of sediment stopped in reservoirs the coefficient of the mechanical denudation was counted, definite by Wiśniewski as the relation of the volume of sediment deposited in the reservoir to the catchment area. The defi-nite approximate value of the denudation, for the help of this coefficient, proved considerably diverse in the individual years in which the measurements of silting were made. The mechanical denudation coefficient was counted for periods before and after desilting of the main reservoir. The results of the calculations of the transportation of ...
Suspended sediment constitutes about 90% of the total river sediment transport. Recognition of river sediment transport, its kind intensity is indispensable in designing, execution, and operation of objects realized for needs of water economy. It is of great importance in water reservoir silting forecast.Intensity of suspended sediment transport may be determined by use of var-ious methods i.e. direct ones - measurement methods and indirect - calculation ones. Among the direct ones the following ones may be distinguished: bathometric, photometric, electro-resistance, ultrasonic and radioisotope method. Indirect methods permit to calculate sediment transport basing upon empiric, semi-empiric and theoretical equations. Description of suspended sediment transport based on empiric investigation is connected with the necessity of introduction of hydraulic parameters describing water flow and parameters characterizing suspended sedi-ment. Introduction of these parameters into description of water and sediment movement requires consideration of their reciprocate dynamic influence. Determi-nation of water flow velocity, distribution in the river bed section, forces, and stresses acting on the bottom characterizing the beginning of movement is also significant. Distribution of suspended sediment concentration, taking into regard its granulometric composition and fall velocity of particular grains, as well as hy-draulic parameters, permit description of transport of the water-sediment mixture and ...
