Sediment flushing of reservoirs is an operational technique, whereby previously accumulated sediments in the reservoirs are hydraulically removed by accelerated flow when the bottom desiltingoutlets of the dam are opened. In this research, the process of sediment flushing is simulated by a three dimensional numerical model in which sediment and flow interaction are reflected in the reservoirs. ...

This study used particle size analysis to investigate the initial accumulation and trap efficiency of radiocesium ((137)Cs) in four irrigation ponds, ~4-5 months after the Fukushima Dai-ichi nuclear power plant (DNPP) accident. Trap efficiency, represented by the inventory of (137)Cs in pond sediment to the inventory of radiocesium in soil surrounding the pond (i.e., total (137)Cs inventory), w...

This paper presents a framework for predicting embryo survival in salmonid spawning gravels as a function of sediment deposition. This framework integrates three quantitative relationships modeling the variations of substrate permeability with sediment deposition, apparent velocity with substrate permeability, and embryo survival rate with apparent velocity. The model allows evaluation of the i...

[1] In this work we combine existing ideas on gravel and sand entrainment into a simulation model for flows that flush sand from the surface and subsurface of a gravel riverbed. A flume experiment is conducted to provide a test of the flushing model. The primary advance represented in this paper is incorporation of a two-fraction entrainment approach into a routing model to account for the effe...

The Water Department will open fire hydrants to flush out sediment that has collected in the water mains during the past year. This flushing program is a standard operating procedure for water departments. Flushing the mains may cause some slight but temporary reduction in water pressure and possible water discoloration. However, your water remains safe for drinking. We suggest you refrain from...

Abstract: Control of reservoir sedimentation in order to ensure their sustainable use has drawn attention among water engineers and water resource managers. Several methods have been proposed, but most of the developed methodologies are incapable of modelling bed evolutions, while at the same time, compute sediment flushing efficiency. In this study a two-dimensional bed evolution model is prop...

The trap efficiency of a shallow reservoir depends on the characteristics of the inflowing sediments and the retention time of the water in the reservoir, which in turn are controlled by the reservoir geometry. With the purpose of controlling the trapped and flushed sediments in shallow reservoirs, the effects of the geometry on sediment deposition and removal were investigated with systematic ...

control of sedimentation in dam reservoirs is considered to be one of the most important issues in exploitation of dams and increasing the their useful life. reservoirs act as traps for sediments and prevent transport of sediment to the river. the deposited sediment decreases the capacity of reservoirs so that they can not be in use any more. various methods dealing with removing part of the de...

This paper highlights a preliminary study on the potential of a tipping flush gate to be used in an open storm drain to remove sediment. The investigation was carried out by using a plasboard model of the tipping flush gate installed in a rectangular flume. A steady flow experiment was carried out to determine the discharge coefficients and also the outflow relationship of the tipping flush gat...