scholarly journals Simplified Simulation Method for Flood-Induced Bend Scour—A Case Study Near the Shuideliaw Embankment on the Cho-Shui River

2017 ◽  
Author(s):  
Wen-Dar Guo ◽  
Jian-Hao Hong ◽  
Cheng-Hsin Chen ◽  
Chih-Chiang Su ◽  
Jihn-Sung Lai
Keyword(s):  
Flow Simulation ◽  
Field Measurements ◽  
Practical Method ◽  
Simulation Method ◽  
Water Levels ◽  
Two Dimensional ◽  
Short Term ◽  
Common Causes ◽  
Two Dimensional Flow

The modeling of flood-induced bend scour near embankment toes can provide important information for river engineering, embankment safety warnings, and emergency action management. During the rainy seasons, short-term general scour and bend scour are the most common causes for the failure of reinforced concrete embankments in Taiwan. To gain a deeper understanding of the scouring process near levee foundations, this study proposed a straightforward and practical method for bend scour simulation. The proposed simulation method is subdivided into three stages: two-dimensional flow simulation, general scour estimation, and bend scour estimation. A new bend-scour computation equation is proposed and incorporated into a two-dimensional hydraulic finite-volume model for simulating the evolution of bend scour depth around embankment toes. The proposed method is applied to simulate the temporal evolution of bend scouring near the Shuideliaw Embankment on the Cho-Shui River in Taiwan, where serious failure occurred during the June 2012 monsoon. Field data were gathered using the numbered-brick technique at the Shuideliaw Embankment to demonstrate the accuracy of the proposed method. The results of the bend scour simulations compared reasonably well with field measurements, indicating close agreement in terms of water levels and bend scour depths near the Shuideliaw Embankment. The proposed method was found to quickly estimate the maximum short-term general scour and bend scour depths for further enhancement of the safety of the embankment toe.

scholarly journals Evaluating Efficiency Improvement of Deep-Cut Curb Inlets for Road-Bioretention Stripes

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3368
Author(s):  
Xiaoning Li ◽  
Chuanhai Wang ◽  
Gang Chen ◽  
Qiang Wang ◽  
Zunle Hu ◽  
...  
Keyword(s):  
Flow Simulation ◽  
Urban Drainage ◽  
Two Dimensional ◽  
Efficiency Improvement ◽  
Sponge City ◽  
The Road ◽  
Wide Range ◽  
Two Dimensional Flow ◽  
Simulation Results

Making a deep cut on the curb inlet has been used in some sponge-city (SPC) projects for road-bioretention stripes to manage stormwater runoff since they were easily implemented in the field. The efficiencies of the deep-cut curb inlets in those projects were unknown for lacking equation to evaluate their efficiencies. Two kinds of retrofit scenarios are commonly used: (1) The curb-cut cases when the deep cut is made only over the width of the curb inlet; (2) the road-curb cut cases when both the curb inlet and a small part of the road surface have a deep cut. An updated two-dimensional flow simulation program, FullSWOF-ZG, was used to determine two important parameters in road curb inlet design: The 100% interception curb inlet lengths (LT) and the curb inlet efficiencies (Eci). Eight-hundred retrofit modeling cases were compared with the no-cut cases to quantify the efficiency improvement of the deep-cut curb inlets. The simulation results show both LT and Eci of the curb-cut cases do not improve much. This case study with limited combinations of longitudinal and cross slopes and inlet lengths demonstrated that Eci of the road-curb cut cases improves to a large extent so that they can be used in the SPC projects and other urban drainage projects to reduce the flooding potentials. A general equation used to design and evaluate the road-curb cut inlets can be developed based on more simulation cases with a wide range of input parameters in a future study.

scholarly journals The influence of long- and short-term volcanic strain on aquifer pressure: a case study from Soufrière Hills Volcano, Montserrat (W.I.)

2020 ◽  
Vol 223 (2) ◽  
pp. 1288-1303
Author(s):  
K Strehlow ◽  
J Gottsmann ◽  
A Rust ◽  
S Hautmann ◽  
B Hemmings
Keyword(s):  
Water Level ◽  
Pore Pressure ◽  
Crustal Deformation ◽  
Water Levels ◽  
Short Term ◽  
Soufriere Hills Volcano ◽  
Soufrière Hills Volcano ◽  
Water Level Changes ◽  
Soufriere Hills

Summary Aquifers are poroelastic bodies that respond to strain by changes in pore pressure. Crustal deformation due to volcanic processes induces pore pressure variations that are mirrored in well water levels. Here, we investigate water level changes in the Belham valley on Montserrat over the course of 2 yr (2004–2006). Using finite element analysis, we simulate crustal deformation due to different volcanic strain sources and the dynamic poroelastic aquifer response. While some additional hydrological drivers cannot be excluded, we suggest that a poroelastic strain response of the aquifer system in the Belham valley is a possible explanation for the observed water level changes. According to our simulations, the shallow Belham aquifer responds to a steadily increasing sediment load due to repeated lahar sedimentation in the valley with rising aquifer pressures. A wholesale dome collapse in May 2006 on the other hand induced dilatational strain and thereby a short-term water level drop in a deeper-seated aquifer, which caused groundwater leakage from the Belham aquifer and thereby induced a delayed water level fall in the wells. The system thus responded to both gradual and rapid transient strain associated with the eruption of Soufrière Hills Volcano (Montserrat). This case study gives field evidence for theoretical predictions on volcanic drivers behind hydrological transients, demonstrating the potential of hydrological data for volcano monitoring. Interrogation of such data can provide valuable constraints on stress evolution in volcanic systems and therefore complement other monitoring systems. The presented models and inferred results are conceptually applicable to volcanic areas worldwide.

scholarly journals Improving applicability of neuro-genetic algorithm to predict short-term water level: a case study

2013 ◽  
Vol 16 (1) ◽  
pp. 218-230 ◽  
Author(s):  
Gooyong Lee ◽  
Sangeun Lee ◽  
Heekyung Park
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Artificial Neural Network ◽  
Water Level ◽  
Neural Network Model ◽  
Artificial Neural Network Model ◽  
River Management ◽  
Water Levels ◽  
Short Term

This paper proposes a practical approach of a neuro-genetic algorithm to enhance its capability of predicting water levels of rivers. Its practicality has three attributes: (1) to easily develop a model with a neuro-genetic algorithm; (2) to verify the model at various predicting points with different conditions; and (3) to provide information for making urgent decisions on the operation of river infrastructure. The authors build an artificial neural network model coupled with the genetic algorithm (often called a hybrid neuro-genetic algorithm), and then apply the model to predict water levels at 15 points of four major rivers in Korea. This case study demonstrates that the approach can be highly compatible with the real river situations, such as hydrological disturbances and water infrastructure under emergencies. Therefore, proper adoption of this approach into a river management system certainly improves the adaptive capacity of the system.

scholarly journals Investigation of the 18O Content of a 100 m Ice Core From the Ronne Ice Shelf, Antarctica

1988 ◽  
Vol 10 ◽  
pp. 43-47 ◽  
Author(s):  
W. Graf ◽  
O. Reinwarth ◽  
H. Moser ◽  
W. Stichler
Keyword(s):  
Flow Model ◽  
Accumulation Rate ◽  
Ice Core ◽  
Snow Accumulation ◽  
Two Dimensional ◽  
Ice Shelf ◽  
Short Term ◽  
The Core ◽  
Two Dimensional Flow ◽  
Field Season

A 100 m ice core from the Ronne Ice Shelf, drilled during the 1983-84 field season, was dated by isotopic stratigraphy, using the well-known seasonal variation in the 18O content in firn and ice; the layers at a depth of 89 m are probably 400 years old. Layer thicknesses deduced from the 18O profile indicate short-term variations of the snow-accumulation rate over the last 400 years. The area of deposition of the material recovered with the core is estimated by a two-dimensional flow model and by the 18O content of the core, which decreases from –27.5‰ in the upper part of the core to –32.0‰ at 89 m depth.

scholarly journals Two-Dimensional Computational Model for Wave Rotor Flow Dynamics

1997 ◽  
Vol 119 (4) ◽  
pp. 978-985 ◽  
Author(s):  
G. E. Welch
Keyword(s):  
Stokes Equations ◽  
Flow Simulation ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Wave Rotor ◽  
Navier Stokes Equations ◽  
Flow Features ◽  
Rotor Experiment ◽  
Two Dimensional Flow ◽  
Rotor Flow

A two-dimensional (θ, z) Navier–Stokes solver for multiport wave rotor flow simulation is described. The finite-volume forms of the unsteady thin-layer Navier–Stokes equations are integrated in time on multiblock grids that represent the stationary inlet and outlet ports and the moving rotor passages of the wave rotor. Computed results are compared with three-port wave rotor experimental data. The model is applied to predict the performance of a planned four-port wave rotor experiment. Two-dimensional flow features that reduce machine performance and influence rotor blade and duct wall thermal loads are identified.

scholarly journals Two-Dimensional Computational Model for Wave Rotor Flow Dynamics

1996 ◽  
Author(s):  
Gerard E. Welch
Keyword(s):  
Stokes Equations ◽  
Flow Simulation ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Wave Rotor ◽  
Performance Impact ◽  
Flow Features ◽  
Rotor Experiment ◽  
Two Dimensional Flow ◽  
Rotor Flow

A two-dimensional (θ,z) Navier-Stokes solver for multi-port wave rotor flow simulation is described. The finite-volume form of the unsteady thin-layer Navier-Stokes equations arc integrated in time on multi-block grids that represent the stationary inlet and outlet ports and the moving rotor passages of the wave rotor. Computed results are compared with three-port wave rotor experimental data. The model is applied to predict the performance of a planned four-port wave rotor experiment. Two-dimensional flow features that reduce machine performance and influence rotor blade and duct wall thermal loads are identified. The performance impact of rounding the inlet port wall, to inhibit separation during passage gradual opening, is assessed.

scholarly journals Transducer Field Imaging Using Acoustography

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Jaswinder S. Sandhu ◽  
Robert W. Schoonover ◽  
Joshua I. Weber ◽  
J. Tawiah ◽  
Vitaliy Kunin ◽  
...  
Keyword(s):  
Current Practice ◽  
Practical Method ◽  
Two Dimensional ◽  
Axial Field ◽  
Cross Sectional ◽  
Scanning Time ◽  
Field Distributions ◽  
Data Points ◽  
Field Imaging

A common current practice for transducer field mapping is to scan, point-by-point, a hydrophone element in a 2D raster at various distances from the transducer radiating surface. This approach is tedious, requiring hours of scanning time to generate full cross-sectional and/or axial field distributions. Moreover, the lateral resolution of the field distribution image is dependent on the indexing steps between data points. Acoustography is an imaging process in which an acousto-optical (AO) area sensor is employed to record the intensity of an ultrasound wavefield on a two-dimensional plane. This paper reports on the application of acoustography as a simple but practical method for assessing transducer field characteristics. A case study performed on a commercial transducer is reported, where the radiated fields are imaged using acoustography and compared to the corresponding quantities that are predicted numerically.

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