Modeling of the Impact of the Rock Fill Weir on River Morphology of Lam Pha Chi River

2021 ◽  
Vol 32 (2) ◽  
Author(s):  
Rakbordin Yeelansuwan ◽  
Wisuwat Taesombat ◽  
Supapap Patsinghasanee
Keyword(s):  
River Morphology ◽  
Rock Fill ◽  
The Impact

scholarly journals Effects of Spur Dikes on Water Flow Diversity and Fish Aggregation

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1822
Author(s):  
Tingjie Huang ◽  
Yan Lu ◽  
Huaixiang Liu
Keyword(s):  
Water Flow ◽  
Diversity Index ◽  
Spur Dike ◽  
Rock Fill ◽  
Aggregation Rate ◽  
Different Types ◽  
Spur Dikes ◽  
Fish Aggregation ◽  
The Impact ◽  
The Relationship

As a typical waterway modification, the spur dike narrows the water cross section, which increases the flow velocity and flushes the riverbed. Meanwhile, it also protects ecological diversity and improves river habitat. Different types of spur dikes could greatly impact the interaction between flow structure and local geomorphology, which in turn affects the evolution of river aquatic habitats. Four different types of spur dikes—including rock-fill, permeable, w-shaped rock-fill, and w-shaped permeable—were evaluated using flume experiments for spur dike hydrodynamics and fish aggregation effects. Based on Shannon’s entropy, an index for calculating water flow diversity is proposed. Additionally, the impact of the different spur dikes on water flow diversity and the relationship between water flow diversity and fish aggregation effects were studied. The water flow diversity index around the spur dike varied from 1.13 to 2.96. The average aggregation rate of test fish around the spur dike was 5% to 28%, and the attraction effect increased with increasing water flow diversity. Furthermore, we plotted the relationship between water flow diversity index and average fish aggregation rate. A fish hydroacoustic study conducted on the Laohutan fish-bone dike in the Dongliu reach of downstream Yangtze River showed that the fish aggregation effect of the permeable spur dike was greater than the rock-fill spur dike. These research results could provide theoretical support for habitat heterogeneity research and ecologically optimal design of spur dikes.

The impact of hydro-powers system development in the Mekong basin on the Hau river morphology process

2021 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Nguyen Dinh Hoang ◽  
Doan Huy Phuong ◽  
Huynh Thi Lan Huong ◽  
Nguyen Xuan Hien
Keyword(s):  
System Development ◽  
River Morphology ◽  
Mekong Basin ◽  
The Impact

A modified approach for determination of nonlinear properties in seismic response analyses for 200 m high core rock-fill dams

2008 ◽  
Vol 45 (8) ◽  
pp. 1064-1072 ◽  
Author(s):  
Hongjun Li ◽  
Shichun Chi ◽  
Gao Lin ◽  
Hong Zhong
Keyword(s):  
Site Response ◽  
Confining Pressure ◽  
In Situ Stress ◽  
Nonlinear Properties ◽  
Rock Fill ◽  
Equivalent Linear ◽  
Wide Range ◽  
Confining Pressures ◽  
The Impact

Equivalent linear analyses are widely used for estimation of site response and safety status of rock-fill dams subjected to strong earthquakes. However, the average normalized curves incorporated in the equivalent-linear iterative process cannot precisely depict the variations of dynamic parameters with shearing strain for one type of soil material under a wide range of confining pressures. Thus, a modified approach for the determination of nonlinear properties for soil elements confined under a broad range of effective pressures in site response analyses for high rock-fill dams (>200 m) is proposed. In this approach, the normalized confining-pressure-interpolating curves (CPI curves) of each soil element under different effective stress are obtained by linearly interpolating or extrapolating by its in situ stress. By comparing the results obtained by equivalent linear analyses incorporating the average curves and the CPI curves, respectively, the impact of utilizing the recommended curves when determining nonlinear soil properties on site response analyses of high rock-fill dams (>200 m) is discussed. It is shown that the refinement in the determination of nonlinear properties during site response can be utilized in the near future by incorporating the results of this study in practice.

The impact of discharge change on physical instream habitats and its response to river morphology

2012 ◽  
Vol 116 (3-4) ◽  
pp. 827-850 ◽  
Author(s):  
Christoph Hauer ◽  
Günther Unfer ◽  
Hubert Holzmann ◽  
Stefan Schmutz ◽  
Helmut Habersack
Keyword(s):  
River Morphology ◽  
The Impact

Sensitivity Analysis of Concrete Face Rock-Fill Dam Parametric Based on the Intelligent Algorithm

2014 ◽  
Vol 580-583 ◽  
pp. 1940-1945
Author(s):  
Qiao Yan ◽  
Zhan Hong Gao ◽  
Zhi Cheng Song
Keyword(s):  
Sensitivity Analysis ◽  
Orthogonal Design ◽  
Model Parameters ◽  
Analysis Method ◽  
Range Analysis ◽  
Unknown Parameters ◽  
Rock Fill ◽  
Dam Deformation ◽  
Parameters Inversion ◽  
The Impact

Sensitivity analysis of model parameters is a rock fill parametric inversion analysis method to determine the unknown parameters. Traditional sensitivity analysis is basically a lot of trial or the method of single factor analysis based on a large amount of calculation, but, unable to reflect the real situation. The method of particle swarm optimization based on neural network based nonlinear mapping relationship between model parameters and displacement to finite element simulation of dam deformation. Basing on the orthogonal design, the methods of range analysis and variance analysis method were used for sensitivity analysis of the parameters of Duncan E-B model and the impact of various parameters on the dam displacement, and then it can be as the parameters of rock fill dam provide basis for determining the unknown parameters inversion.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

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