scholarly journals Revisions to suspended-sediment concentration, percent smaller than 0.063 millimeter, and instantaneous suspended-sediment discharge reported for a cooperative program between the U.S. Geological Survey and the U.S. Army Corps of Engineers in the lower Mississippi-Atchafalaya River Basin, October 1989 to February 2015

Author(s):  
Katherine K. Norton ◽  
Lisa D. Olsen ◽  
Todd E. Baumann ◽  
Lane B. Simmons ◽  
Athena P. Clark ◽  
...  
2020 ◽  
Vol 13 (21) ◽  
Author(s):  
Caiwen Shu ◽  
Guangming Tan ◽  
Yiwei Lv ◽  
Quanxi Xu

AbstractUsing experimental data of near-bed suspended sediment concentrations at five typical hydrometric stations of the Three Gorges Reservoir at the early reserving stage, the differences were investigated between the common method and improved method during flood seasons and non-flood seasons. The impact of taking measurements below 0.2 times the water depth on the results was discussed. The results show that the average discharges and velocities at each station calculated by the common method were slightly larger than those calculated by the improved method. Regarding the suspended sediment concentration at each station, the errors in the reservoir and downstream channels in dynamic equilibrium state were small, and the largest errors occurred where the river bed was strongly scoured in the downstream reach below the large dam. There was no significant relationship between water discharge and flow velocity, and the missed measurement phenomenon also occurred. The sediment discharge error was affected by the suspended sediment concentration, implying that errors usually occurred in channels with serious erosion during flood seasons. The correction coefficients (R2) of sediment discharge at each station were given during the experiment, which showed that the sediment discharges at the hydrometric stations where a large amount of sediment transport occurred near the river bottom, needed to be modified. Furthermore, the test methods proposed in this study were applied to calculate the sediment discharges of three rivers, and the results indicate that this method can narrow the gap between bathymetric comparisons and sediment load measurements.


1981 ◽  
Vol 2 ◽  
pp. 103-108 ◽  
Author(s):  
O. P. Shcheglova ◽  
O. P. Chizhov

All available data on suspended sediment concentration and sediment discharge for Central Asian rivers have been used to estimate the small-grained sediment discharge from glaciated areas. Glacial streams discharge the bulk of suspended material during the period of intensive melting (July to September). There is a good exponential relationship between the suspended sediment concentration (or sediment discharge) and air temperature over glaciers. The area of the largest glacier in the watershed is another factor influencing the silt content and sediment run-off. Its contribution is smaller than that of air temperature. Yearly sediment run-off for glacial rivers in the Pamir and Tien Shan has been computed. Highest values are from the Pamir with many rivers yielding 3000 tonnes km–2 (11 200 tonnes km–2 for the Vukhsh river). The highest run-off in Tien Shan is 2 000 tonnes km–2 for the Chatkal river.


2019 ◽  
Vol 5 (3) ◽  
pp. 243
Author(s):  
Bambang Yulistiyanto ◽  
Bambang Kironoto ◽  
Bangun Giarto ◽  
Mariatul Kiptiah ◽  
Muhammad Lutfi Tantowi

The accumulation of suspended sediment reduces the capacity in the river and deteriorates the water quality. Kuning  River in Yogyakarta is one of the main rivers in Yogyakarta, Indonesia, which is currently facing the issue of suspended sediments. To reduce the effect of suspended sediment and determine a preventive measure, hence, it is necessary to study the characteristics of the suspended sediment flow. Therefore, this study aims to investigate the suspended sediment flow characteristics, i.e. the velocity, and the concentration profiles at specific points in the transverse direction of the channel as well as the correlation of the suspended sediment discharge. Thirty (30) profiles of velocity and suspended sediment concentration were measured at six different points along the Kuning River. Opcon probe was used to measure suspended sediment concentration, while the propeller current meter was used to measure mean point-velocity profiles. Results of this study show the suspended sediment discharge ratio, defined as  are higher in the middle part of the channel than the one near the edge of the channel. The position of z/B where the values of  1 occurs at z/B = 0,19 and z/B = 0,75, which depend on the irregularity of the channel cross-sections. For practical purposes, the depth-averaged velocity and suspended sediment concentration can be determined from 1, 2 and/or 3 points measurement at y = 0,2D, 0,4D and 0,8D.


2013 ◽  
Vol 11 (4) ◽  
pp. 457-466

Artificial neural networks are one of the advanced technologies employed in hydrology modelling. This paper investigates the potential of two algorithm networks, the feed forward backpropagation (BP) and generalized regression neural network (GRNN) in comparison with the classical regression for modelling the event-based suspended sediment concentration at Jiasian diversion weir in Southern Taiwan. For this study, the hourly time series data comprised of water discharge, turbidity and suspended sediment concentration during the storm events in the year of 2002 are taken into account in the models. The statistical performances comparison showed that both BP and GRNN are superior to the classical regression in the weir sediment modelling. Additionally, the turbidity was found to be a dominant input variable over the water discharge for suspended sediment concentration estimation. Statistically, both neural network models can be successfully applied for the event-based suspended sediment concentration modelling in the weir studied herein when few data are available.


Sign in / Sign up

Export Citation Format

Share Document