نتایج جستجو برای: check dams
تعداد نتایج: 60439 فیلتر نتایج به سال:
With Taiwan’s steep terrain and fracture geology, natural disasters are likely to occur after heavy rainfall. To reduce the effects of upstream sediment on human surroundings, check dams are an essential transverse structure for streams in watersheds. However, there is likely to be a detrimental visual impact on the landscape without consideration of the integration of dams with the environment...
The purpose of this study was investigating the effect of eleven gabion and five masonry dams on trapping eroded particles in the razin watershed located north of Kermanshah township. The frequency of sand particles increased by 40.67 percent and the percentage of gravel, silt and clay particles decreased by 14.37, 56.55 and 69.93 percent in sediments behind the gabion dams as compared to the w...
Check dams are one of the structures used to control debris flows. In this study, in order to evaluate the effect of hydraulic parameters on debris sediment trapping rate by the slit trapezoidal check dams with different angles, and to develop an empirical relation for determination of trapping coefficient of the dam reservoirs, three physical models of the check dams were used. The tests were ...
In this research, fractal relationships were used to evaluate the particle size distribution of the check dam. Three check dams with height of 2, 2 and 2.6 meters were selected and the hole was drilled same the height of the check dam at the sediment deposits. Then, depending on the color of the deposited layers, the thickness of the layers was determined and sampling was down from each layer t...
The objective of current study was to invstigate the accuracy of Tyler and Wheatcraft, Bird et al. and Kravchenko and Zhang fractal models in describing particle size distribution (PSD) of sediment in 14 successive check dams for two depths of 0-15 and 15-30 cm. Sediment PSD were determined in 28 samples using hydrometer method . The referred fractal models were fitted on sediments PSD data. Re...
The design of open check dams at mountain rivers for flood protection has an essential impact on the sediment budget of downstream river reaches. A key issue is the bedload transfer hindering and retention which can be influenced by the geometry of the openings of check dams. Contemporary design concepts provoke the retention of too much or insufficient bedload with regard to the downstream tra...
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