Sensitivity Analysis of Water Level and Flow According to the Parameter Change

2017 ◽  
Vol 18 (6) ◽  
pp. 594-603
Author(s):  
Mi Jung Kim ◽  
Seung Seop Ahn ◽  
Ki Bum Park
Keyword(s):  
Sensitivity Analysis ◽  
Water Level ◽  
Parameter Change

scholarly journals Sensitivity Analysis of Storm Duration for Development of Flood Map at Bertam Catchment, Cameron Highlands.

2018 ◽  
Vol 7 (4.35) ◽  
pp. 323
Author(s):  
W.N.C.W. Zanial ◽  
M.A. Malek ◽  
N.A.A. Aziz
Keyword(s):  
Sensitivity Analysis ◽  
Water Level ◽  
Stream Flow ◽  
River Flow ◽  
Flood Hazard ◽  
Mitigation Measures ◽  
Hazard Map ◽  
Design Storm ◽  
Flood Hazard Map ◽  
Storm Duration

The current changes in climate have marked significant impacts in our daily weather. The changes have affected the trend, pattern and magnitude of rainfall-runoff as compared to the events commonly experienced. Flood is one of the effects of weather and climate change. Floods can be classified as one of the most devastating natural hazards and is a major concern to the country as it causes damages to human lives, environment, agriculture, land and structures. Therefore, effective flood planning and mitigation measures should be carried out in order to reduce the effects of flooding. Flood hazard map is one of the non-structural mitigation measures that can be used for planning purposes. Flood can be directly estimated or derived from frequency analysis when long duration of stream flow records is available. However, in the case of limited or no stream flow data available, design storm are generally used to estimate design flood. Downstream of Bertam Catchment is an ungauged river station where no flow records are available. Based on this limitation, in this study, design storm was used to design the flood map. Info Works RS was used to develop the flood model and sensitivity analysis of the design storm was performed. Results obtained in this study presented the comparison of flow between 100-years Annual Recurrence Interval (ARI) at various storm durations of 0.25hr, 0.5hr, 1hr, 3hrs, 6hrs, 12hrs, 1 day, 2days and 3 days. The maximum flow is found to be at 6hrs storm duration at 1103.418m3/s. Besides river flow, comparison of water level at 100-year ARI of various storm durations was also conducted. Results obtained from this study found that 24hrs storm duration will produce the highest water level at 1034.753m. By comparing the flow and water level, the result from river flow produces the maximum at 6hrs storm duration while the result of water level gives the maximum at 24hrs storm duration. Since, water level is preferable in producing flood hazard mapping at 2-D view, therefore, the storm duration is chosen based on results of sensitivity storm duration on water level conducted. Comparison is then conducted between 24-hrs storm duration at various ARIs. It can be concluded that 100-years ARI will lead to the maximum value of 1034.910m  water level. Suitable storm duration and Annual Recurrence Interval (ARI) are to be determined in order to produce the best flood hazard map. In this study, it is found that 100-years ARI and 24hrs storm duration are the best combination, performed based on water level.

scholarly journals Proposed Swedish Spillway Design Guidelines Compared with Historical Flood Marks at Lake Siljan

1989 ◽  
Vol 20 (4-5) ◽  
pp. 293-304 ◽  
Author(s):  
Joakim Harlin
Keyword(s):  
Sensitivity Analysis ◽  
Water Level ◽  
Frequency Analysis ◽  
Return Period ◽  
Design Guidelines ◽  
Water Levels ◽  
Spring Flood ◽  
Design Flood ◽  
Design Floods ◽  
Modelling Assumptions

A comparison between the proposed Swedish spillway design floods and historic flood marks made at lake Siljan in central Sweden, is shown. Frequency analysis is performed incorporating pregauge information on water levels together with a sensitivity analysis of modelling assumptions. A water level of 0.42 to 0.75 metres above the highest historic flood mark (166.10 m.a.sl., 1659) was obtained when routing the design spring flood through lake Siljan. The design autumn flood lifted the lake to 1.56 to 1.52 metres below the highest flood mark. Return period for the design spring and autumn flood was estimated to about 1,000 years. The uncertainty in frequency analysis proved to have larger impact than modelling assumptions on estimating the risk of the design flood.

scholarly journals Sensitivity Analysis of Anchored Slopes under Water Level Fluctuations: A Case Study of Cangjiang Bridge—Yingpan Slope in China

2021 ◽  
Vol 11 (15) ◽  
pp. 7137
Author(s):  
Jinxi Liang ◽  
Wanghua Sui
Keyword(s):  
Sensitivity Analysis ◽  
Slope Stability ◽  
Water Level ◽  
Controlling Factors ◽  
Slope Instability ◽  
Water Level Fluctuations ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Slope Inclination ◽  
Main Controlling Factors

This paper presents an improved slope stability sensitivity analysis (ISSSA) model that takes anchoring factors into consideration in umbrella-anchored sand and clay slopes under reservoir water level fluctuation. The results of the ISSSA model show that the slope inclination and the layout density of anchors are the main controlling factors for sand slope stability under fluctuation of the water level, while the slope inclination and water head height are the main controlling factors for slope stability in the Cangjiang bridge—Yingpan slope of Yunnan province in China. Moreover, there is an optimum anchorage angle, in the range of 25–45 degrees, which has the greatest influence on slope stability. The fluctuation of the reservoir water level is an important factor that triggers slope instability; in particular, a sudden drop in the surface water level can easily lead to landslides; therefore, corresponding measures should be implemented in a timely manner in order to mitigate landslide disasters.

scholarly journals Towards a Correlation between Long-Term Seawater Intrusion Response and Water Level Fluctuations

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 719
Author(s):  
Antoifi Abdoulhalik ◽  
Ashraf A. Ahmed ◽  
Abdelrahman M. Abdelgawad ◽  
G. A. Hamill
Keyword(s):  
Sensitivity Analysis ◽  
Steady State ◽  
Linear Relationship ◽  
Water Level ◽  
Linear Function ◽  
Seawater Intrusion ◽  
Water Level Fluctuations ◽  
Management Perspective ◽  
Perform Sensitivity Analysis ◽  
Water Level Variations

Laboratory and numerical experiments were conducted to provide a quantitative steady-state analysis of the effect of incremental variations of water level on saltwater intrusion. The purpose was to seek mathematical correlations relating both the wedge toe length and the height along the coastline to the boundary head difference. The laboratory experiments were completed in a 2D sand tank where both freshwater and seawater levels were varied. The experiments were conducted for two bead sizes having different hydraulic conductivities. The numerical model SEAWAT was used to validate the results and then to perform sensitivity analysis. The experimental results show that at steady-state conditions, the logarithmic toe length could be expressed as a linear function of the boundary head difference. The linear relationship was recorded in both advancing and receding wedge phases. The linearity of the correlation was also well demonstrated with analytical solutions. Similar relationships were also derived in the scenarios where the sea level fluctuated while the freshwater boundary head was constant. The height of the saltwater wedge along the coastline was also found to be a linear function of the boundary head difference. The sensitivity analysis shows that the regression coefficients were sensitive to the hydraulic conductivity, the dispersivity, and the saltwater density, while the porosity and the rate of boundary head change induced negligible effects. The existence of a linear relationship between the logarithmic toe length and the boundary head difference was also well evidenced in a field-scale aquifer model for all the different hydrogeological aquifer conditions tested. This study is the first attempt in identifying the underlying correlation between the boundary water level variations and the main seawater intrusion (SWI) external metrics under controlled laboratory conditions, which is of great relevance from a water resources management perspective.

scholarly journals The potential for remote sensing and hydrologic modelling to assess the spatio-temporal dynamics of ponds in the Ferlo Region (Senegal)

2010 ◽  
Vol 14 (8) ◽  
pp. 1449-1464 ◽  
Author(s):  
V. Soti ◽  
C. Puech ◽  
D. Lo Seen ◽  
A. Bertran ◽  
C. Vignolles ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Sensitivity Analysis ◽  
Water Level ◽  
Catchment Area ◽  
Remote Sensing Data ◽  
Pond Water ◽  
Hydrologic Model ◽  
Main Stream ◽  
Sensing Data ◽  
Water Height

Abstract. In the Ferlo Region in Senegal, livestock depend on temporary ponds for water but are exposed to the Rift Valley Fever (RVF), a disease transmitted to herds by mosquitoes which develop in these ponds. Mosquito abundance is related to the emptying and filling phases of the ponds, and in order to study the epidemiology of RVF, pond modelling is required. In the context of a data scarce region, a simple hydrologic model which makes use of remote sensing data was developed to simulate pond water dynamics from daily rainfall. Two sets of ponds were considered: those located in the main stream of the Ferlo Valley whose hydrological dynamics are essentially due to runoff, and the ponds located outside, which are smaller and whose filling mechanisms are mainly due to direct rainfall. Separate calibrations and validations were made for each set of ponds. Calibration was performed from daily field data (rainfall, water level) collected during the 2001 and 2002 rainy seasons and from three different sources of remote sensing data: 1) very high spatial resolution optical satellite images to access pond location and surface area at given dates, 2) Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Model (DEM) data to estimate pond catchment area and 3) Tropical Rainfall Measuring Mission (TRMM) data for rainfall estimates. The model was applied to all ponds of the study area, the results were validated and a sensitivity analysis was performed. Water height simulations using gauge rainfall as input were compared to water level measurements from four ponds and Nash coefficients >0.7 were obtained. Comparison with simulations using TRMM rainfall data gave mixed results, with poor water height simulations for the year 2001 and good estimations for the year 2002. A pond map derived from a Quickbird satellite image was used to assess model accuracy for simulating pond water areas for all the ponds of the study area. The validation showed that modelled water areas were mostly underestimated but significantly correlated, particularly for the larger ponds. The results of the sensitivity analysis showed that parameters relative to pond shape and catchment area estimation have less effects on model simulation than parameters relative to soil properties (rainfall threshold causing runoff in dry soils and the coefficient expressing soil moisture decrease with time) or the water loss coefficient. Overall, our results demonstrate the possibility of using a simple hydrologic model with remote sensing data to track pond water heights and water areas in a homogeneous arid area.

3D Numerical Simulation of Majiabian Concrete Gravity Dam

2011 ◽  
Vol 90-93 ◽  
pp. 2624-2632
Author(s):  
Lin Ke Li ◽  
Ai Jun Zhang ◽  
Jin Yu Liu ◽  
Chun Jiao Hou ◽  
Hao Dong Li
Keyword(s):  
Numerical Simulation ◽  
Sensitivity Analysis ◽  
Stability Analysis ◽  
Water Level ◽  
Deformation Modulus ◽  
Gravity Dam ◽  
Tension Stress ◽  
Concrete Gravity Dam ◽  
3D Numerical Simulation ◽  
The Stability

A new method that 3D numerical simulation combined with anti-cut stability analysis is employed to analyze the stability of Majiabian gravity dam, and the results of the analysis conform to the measured value. And this method can be used in analysis of congener gravity dam. When the results of 2D sliding stability analysis satisfy Code’s requirements, elastic material can be used in 3D numerical simulation. The results of water level sensitivity analysis and deformation modulus of its foundation sensitivity analysis indicates that this gravity dam is insensitive to water level; grouting method can be adopted to enhance its foundation. The results of abutment under tension stress analysis indicate that tension stress of abutment must be considered in high gravity dam design, and arch can be used for reducing the tension stress.

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