In the world professional literature can find many formulae and the nomograph using to apprise of sediment trap efficiency of water reservoirs. Sediment trap efficiency of water reservoirs, introduces in the form of nomograph or formulae, is defined in the function of the coefficients which they are the most often: capacity- inflow ratio – C/I and capacity-watershed ratio – C/W. The reservoir sediment trap efficiency is determined from Łopatin’s, Drozd’s, Karaušev’s, Brune’s formulae in dependence on the capacity-inflow ratio. The C/W ratio is used methods of Brune-Allen’s, Brown’s and Gottschalk’s. Churchill defined the reservoir sediment trap efficiency in function of sedimentation index. Qualification of sediment trap efficiency of small water reservoirs creates considerable difficulties, because the majority of existing formulae and nomograph using to apprise of sediment trap efficiency was worked out in the result of the investigations of large and middle water reservoirs. The results of real sediment trap efficiency of the small water reservoir βrz in the following years of operation were introduced in this work. Sediment trap efficiency was qualified on the basis of several the measurements of silting and on the basis of calculations of the quantity of suspended sediment delivered to the water reservoir. The ...
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 ...
The study and the qualification of the spatial distribution of accumulated bottom sediments in small reservoirs is considerably not only on the design stage, but also during the of operation. The majority of investigative papers concerns to the distributions of the accumulated sediments in average and large water reser-voirs. In this work was introduced and describes for the help of the Dendy's method the spatial distribution of the accumulated sediments in the main water reservoir at Zesławice in the period before and after his desilting.In consideration of building the side reservoir, which to take of the functions of the main reservoir in the period its desilting and reconstruction, the conditions of the flow of the water and the sediment was change. It is had the impact on the dis-tribution of the bottom sediments in the main reservoir.It was showed in this work, on the basis of the executed measurements of silting and the determined the silting degree of the main reservoir, that the decrease the intensity of silting studied reservoir had taken place in the result of the split of water and sediment and it also influenced on the change of the spatial distribution of the sediment deposited. It was ...
