The results of investigations carried out in the stream Bukowiński are pre-sented in this paper. The aim of investigation was definition of influence of wood jam on change of dimensionless coefficient of resistance and coefficient of rough-ness. The performed measurements included cross-section leveling and longitudinal leveling of the stream channel, bed sediment sampling, and hydrometric meas-urements. Cross-section leveling included five cross-sections in the 47-m long stream sector; these were located upstream and downstream the wood jam and in its region. Differentiation of water flow velocity in the region of wood log was shown. The dimensionless coefficient of resistance was calculated taking into ac-count the equivalent bottom roughness determined by use of Gladki`s formulae [van Rijn 1984]. In the aim of the qualification of the equivalent bottom roughness three samples of bottoms sediment were taken in the cross-section with the log. It was found that the wood log in the Bukowiński stream caused a change of hydraulic conditions of water flow and, in consequence, the dimensionless coefficient of resistance in the wood jam section increased by about 71%. The coefficient of channel roughness was also determined and it was shown that the coefficient of roughness in the section of wood jam, ...
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 ...
The work aimed at the determination of the silting degree and the silting forecast for water reservoirs at Brzóza Stadnicka and at Brzóza Królewska, which are situated on hydrologically uncontrolled Tarlaka stream. The analysis took into account the influence of upper reservoir - Brzóza Stadnicka - on the amount of se-diment flowing into the lower reservoir - Brzóza Królewska. The analysis of the silting process was carried out in three variants. The first one concerns to the Brzóza Stadnicka reservoir, the second to the Brzóza Królewska reservoir, without taking into consideration the upper reservoir, and the third variant took into ac-count the influence of the upper reservoir on the lower one. It was stated that stu-died small water reservoirs were characterized relatively low values of the sediment trap efficiency what causes extension of their useful life. Sediment trap efficiency of Brzóza Stadnicka reservoir determined on the basis of the balance of the volume of sediment delivered and deposited in this reservoir is carried out 27.9%. The somewhat higher value βrz = 38.7% the Brzóza Królewska reservoir is characterizes. It was also stated that the upper reservoir of the cascade had the in-significant impact on decrease of the silting intensity ...
