scholarly journals Case Study: Risk Analysis by Overtopping During an Upstream Landslide in Peñitas Dam, Mexico

2019 ◽  
Author(s):  
Humberto J. F. Marengo ◽  
Alvaro A. Aldama
Keyword(s):  
Risk Analysis ◽  
Water Levels ◽  
Risk And Uncertainty ◽  
Empirical Formulas ◽  
Explicit Equation ◽  
Systematic Risks ◽  
Natural Dam ◽  
Risk And Reliability Analysis ◽  
Dam Overtopping

Abstract. Risk and uncertainty analysis by mathematical and statistical methods is often used to assess systematic risks and uncertainties. This research presents the procedure and application of risk and reliability analysis to dam overtopping (Peñitas) located downstream of a natural dam that could have failed. For the analysis are used six statistical variables and their uncertainties, the peak flood of the upstream dam, are evaluated with empirical formulas. The highest water levels of the break dam event were computed using reservoir routing with an explicit equation developed by the authors. Afterward, the overtopping risk analysis of Peñitas Dam was assessed for different stages of excavation of the natural dam that were made during making a sensitivity analysis of duration of dam break event, and also is calculated the possible upper elevation of Peñitas dam, finding that is a recommended practice measurement in similar further cases. A methodology to do an orderly and consistently analysis of risk is proposed to solve similar situations.

Risk Analysis for Dam Overtopping—Feitsui Reservoir as a Case Study

2007 ◽  
Vol 133 (8) ◽  
pp. 955-963 ◽  
Author(s):  
Jan-Tai Kuo ◽  
Ben-Chie Yen ◽  
Yung-Chia Hsu ◽  
Huei-Fen Lin
Keyword(s):  
Risk Analysis ◽  
Feitsui Reservoir ◽  
Dam Overtopping

scholarly journals Overtopping Risk Analysis of Earth Dams considering Effects of Failure Duration of Release Structures

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Lijun Liu ◽  
Zhenyu Wu
Keyword(s):  
Risk Analysis ◽  
Safety Margin ◽  
Dam Safety ◽  
Earth Dams ◽  
Emergency Plans ◽  
Seismic Landslides ◽  
Rockfill Dam ◽  
The Earth ◽  
Dam Overtopping

For modern high earth dams, sufficient safety margin is considered in the designs of flood discharge capacity and dam crest elevation to prevent flood overtopping. However, for high earth dams which may induce catastrophic consequences, during their long operational period, extremely hazardous scenarios which could occur and threaten dam safety need to be considered. For the earth dams located in areas with intensive seismicity, there is a possible scenario that the release structures fail due to seismic landslides and gate failures caused by a severe earthquake when the flood begins to enter the reservoir. Thus, it is desirable to investigate the influence of failure duration of release structures on dam overtopping risk. Based on the Bayesian network, a methodology for overtopping risk analysis of earth dams considering effects of failure duration of release structures is proposed. The overtopping risk of the PBG earth-rockfill dam was analyzed to illustrate the methodology. The critical release structures which dominate the dam overtopping risk are identified. The dam overtopping risk is most sensitive to the failure duration of the spillway. The tolerable failure duration of the spillway is approximately 3 days, and when the failure duration of the spillway reaches 4 days, the dam overtopping risk drastically rises to an unacceptable level. The case study suggests that the proposed methodology could be helpful to analyze the influences of possible failure durations of release structures on dam overtopping risk and could facilitate preparation for emergency plans.

scholarly journals Investigation into the Cause of Iron-Related Clogging of Groundwater Bores Used for Viticulture in the Limestone Coast, South Australia

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 683
Author(s):  
Birte Moser ◽  
Meruyert Beknazarova ◽  
Harriet Whiley ◽  
Thilini Piushani Keerthirathne ◽  
Nikki Harrington ◽  
...  
Keyword(s):  
Groundwater Resources ◽  
South Australia ◽  
Water Levels ◽  
Clear Correlation ◽  
Problem Analysis ◽  
Persistent Problem ◽  
Root Cause ◽  
Complex Interactions ◽  
Iron Manganese

Iron-related clogging of boreholes, pumps and dripper lines is a significant and costly problem for irrigators worldwide. The primary cause of iron-related clogging is still debated. Previous studies have described complex interactions between biological clogging and inorganic iron/manganese oxide precipitation. This case study examined groundwater bores used for viticulture irrigation in the Limestone Coast region, a highly productive wine growing area in the SE of South Australia. Iron clogging of bore screens, pumps and dripper systems has been a persistent problem in the region and the issue is perceived to be growing, with irrigators suggesting the widespread introduction of iron-related bacteria (IRB) through drilling equipment to be the root cause of the problem. Analysis of the groundwater microbiology and inorganic chemistry found no apparent correlation between the presence of IRB and the clogging status of wells. In fact, IRB proved to be widespread throughout the limestone aquifer. However, a clear correlation could be found between clogging affected bores and the redox potential of the groundwater with the most severely affected bores strongly oversaturated in respect to iron oxide minerals. Elevated dissolved concentrations of Fe(II) thereby tended to be found in deeper bores, which also were generally more recently drilled. Following decades of less than average rainfall, a tendency to deepen bores in response to widespread declines in water levels has been documented for the SE of South Australia. The gradually widening clogging problem in the region is postulated to be related to the changes in climate in the region, with irrigators increasingly driven to rely on deeper, anoxic iron-rich groundwater resources.

Experiments on the characteristics of breach variations due to natural dam overtopping

2021 ◽  
Vol 80 (10) ◽  
Author(s):  
Xiangang Jiang ◽  
Wencai Xu ◽  
Xiaoqing Chen ◽  
Huayong Chen ◽  
Chunhu Zhang
Keyword(s):  
Natural Dam ◽  
Dam Overtopping

scholarly journals Risk analysis of gas leakage in gas pressure reduction station and its consequences: A case study for Zahedan

Heliyon ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. e06911
Author(s):  
Peiman Dadkani ◽  
Esmatullah Noorzai ◽  
AmirHossein Ghanbari ◽  
Ali Gharib
Keyword(s):  
Risk Analysis ◽  
Gas Pressure ◽  
Pressure Reduction ◽  
Gas Leakage ◽  
Pressure Reduction Station

scholarly journals Rainfall Threshold for Flash Flood Warning Based on Model Output of Soil Moisture: Case Study Wernersbach, Germany

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1061
Author(s):  
Thanh Thi Luong ◽  
Judith Pöschmann ◽  
Rico Kronenberg ◽  
Christian Bernhofer
Keyword(s):  
Soil Moisture ◽  
Flash Flood ◽  
Rainfall Threshold ◽  
Probability Of Detection ◽  
Water Levels ◽  
Critical Success ◽  
Flood Warning ◽  
Critical Discharge ◽  
Critical Success Index

Convective rainfall can cause dangerous flash floods within less than six hours. Thus, simple approaches are required for issuing quick warnings. The flash flood guidance (FFG) approach pre-calculates rainfall levels (thresholds) potentially causing critical water levels for a specific catchment. Afterwards, only rainfall and soil moisture information are required to issue warnings. This study applied the principle of FFG to the Wernersbach Catchment (Germany) with excellent data coverage using the BROOK90 water budget model. The rainfall thresholds were determined for durations of 1 to 24 h, by running BROOK90 in “inverse” mode, identifying rainfall values for each duration that led to exceedance of critical discharge (fixed value). After calibrating the model based on its runoff, we ran it in hourly mode with four precipitation types and various levels of initial soil moisture for the period 1996–2010. The rainfall threshold curves showed a very high probability of detection (POD) of 91% for the 40 extracted flash flood events in the study period, however, the false alarm rate (FAR) of 56% and the critical success index (CSI) of 42% should be improved in further studies. The proposed adjusted FFG approach has the potential to provide reliable support in flash flood forecasting.

scholarly journals Integrating Schedule Risk Analysis with Multi-Skilled Resource Scheduling to Improve Resource-Constrained Project Scheduling Problems

2021 ◽  
Vol 11 (2) ◽  
pp. 650
Author(s):  
Muritala Adebayo Isah ◽  
Byung-Soo Kim
Keyword(s):  
Risk Analysis ◽  
Project Scheduling ◽  
Resource Scheduling ◽  
Scheduling Problems ◽  
Project Schedule ◽  
Risk And Uncertainty ◽  
Resource Constrained ◽  
Resource Constrained Project Scheduling ◽  
Schedule Risk ◽  
Schedule Risk Analysis

Construction projects are planned in a complex and dynamic environment characterized by high risks and uncertainties amidst resource constraints. Assessing construction schedule risk facilitates informed decision-making, especially in a resource-constrained situation, and allows proactive actions to be taken so that project objectives are not jeopardized. This study presents a stochastic multiskilled resource scheduling (SMSRS) model for resource-constrained project scheduling problems (RCSPSP) considering the impact of risk and uncertainty on activity durations. The SMSRS model was developed by integrating a schedule risk analysis (SRA) model (developed in MS Excel) with an existing multiskilled resource scheduling (MSRS) algorithm for the development of a feasible and realistic schedule. The computational experiment carried out on three case projects using the proposed SMSRS model revealed an average percentage deviation of 10.50%, indicating the inherent risk and uncertainty in activity durations of the project schedule. The core contribution of the proposed SMSRS model is that it: (1) presents project practitioners with a simple tool for assessing the risks and uncertainty associated with resource-constrained project schedules so that necessary response actions can be taken to ensure project success; (2) provides the small-scale construction businesses with an affordable tool for evaluating schedule risk and developing a feasible and realistic project schedule.

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