4. When the sediment concentration reaches 500-600kg/m3 in the Weihe River, the velocity distribution along the vertical still follows the logarithmic distribution.
In order to seek the unity of buoy standard, it is suggested that the bulk density G of all kinds of buoys should be fix as 7, 84×10~3 N/m~3 and the resistance coefficience A of a buoy used on rivers with lower sediment concentration as 0.023. For the convenience to applicate, the paper gave out the table for selection of the resistance coefficient A according to the sediment concentration of flow.
This study shows that the event-averaged suspended sediment concentration C=35 kg/m~3 and the event-averaged index C/Q=(0.015 kg·s)/m~6 are the optimal values for the optimization of F_s, and so is the bankfull water discharge.
the correlated equation of sedimentcontent and unit discharge is Q=0. 7976-0.0012S, with a coefficient of-0. 8. The efficiency of theplant decreases as the sediment content increases.
The daily average sediment content in two big floods in the years of 1988 and 1989 was increased by 88. 7% in comparison with the pre-mining with the same flood discharge.
The Nianchu river has increased 28.3% and 16.4% on sediment yield and sediment content, while the Lasha river has increased 87.9% and 50% respectively since 1990s.
The basic equation is similar to the reference[2], but the ratio of the bottom silt concentration to the vertical average concentration is unequal to the relevant ratio of silt carrying capacity.
Based on the observed data of the Yellow River Estuary, the relation between the condition of sediment transportation of the Yellow River Estuary and the discharge, silt concentration, grain dameter, channel configuration of the estuary have been studied in this paper.
Based on the above,the distribution of suspended sediment concentration are simulated,the result of wich was compared with the mean sediment load in the same vertical of monitoring points proving that the simulation was successful.
4 ) when most of sediment load of a river is carried by hyperconcentration flood and floods with low sediment concentration which are the main cause of bank erosion occur rarely, a stable narrow and deep channel is formed to suit hyperconcentration floods.
Scouring is taking place when sediment consentration of the flow is higher than 600kg/m~3 or less than 100 kg/m~3, and siltation occurs when sediment consentration is in a range of 100~600 kg/m~3. Therefore the regulirity of the sediment delivery and annual sediment load at the outlet section of the river cannot reflect a real regime of sediment yield on the river basion.
The function of the system includes input of velocity and sediment concentration,computation of tidal volume,sediment load at specified sections and printing of the corresponding forms as well as tidal harmonic analysis and predication by use of component tide optimization.
An analysis of variations in suspended sediment concentration (SSC) over one year is presented for the joint area between the Yangtze Estuary and the Hangzhou Bay.
Seasonal changes in sea level, tidal range, wind, riverine discharges, nearshore SSC (suspended sediment concentration) and bed-level of intertidal flat at 4 different sites were shown.
Using bottom field research facilities, detailed measurements of near-bottom currents and suspended sediment concentration distribution within 1.0 m above bed have been obtained in the Changjiang Estuary - a high concentration estuary.
Nine groups of water bodies are used to demonstrate the existence of a relationship between the bottom sediment content of organic matter, forms of phosphorus and calcium, and the morphometric characteristics of lakes.
Fungal dominance of microbial standing crops declined when autumn leaves bent downward and acquired a large sediment content (ash=35% of dry matter); the bacterial crop then rose to 7% of the total microbial crop.
Regular recordings of the phytoplankton community in the water column showed that only these specific bloom species could be the source of the sediment content of diatoms and chlorophyll a.
Many researchers, such as Qian Ning et al., have found that the sediment load of the Yellow River comes mainly from the sandy and gritty area of the Loess Plateau.
The average annual runoff accounts for 16% and the sediment load 26% of the total at Yichang therefore it's one of the main contributors of sediment to the Three Gorges Reservoir.