scholarly journals Hydrological Risk Analysis of Dams: The Influence of Initial Reservoir Level Conditions

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 461 ◽  
Author(s):  
Ivan Gabriel-Martin ◽  
Alvaro Sordo-Ward ◽  
Luis Garrote ◽  
Isabel Granados
Keyword(s):  
Risk Analysis ◽  
Flood Control ◽  
Evaluation Method ◽  
Risk Index ◽  
Flood Routing ◽  
Dam Safety ◽  
Global Risk ◽  
Reservoir Level ◽  
Design Flood ◽  
Relevant Variable

In this paper, we present a method to assess the influence of the initial reservoir level in hydrological dam safety and risk analysis. Traditionally, in professional practice, the procedures applied are basically deterministic. Several physical processes are defined deterministically, according to the criteria of the designer (usually in the conservative side), although there is a high degree of uncertainty regarding these processes. A relevant variable is the reservoir level considered at the beginning of flood events. Hydrological dam safety assessment methods traditionally assume that the reservoir is initially full when it receives the design flood, thus, staying in the conservative side when designing a new dam. However, the distribution of reservoir levels at the beginning of flood episodes takes more importance for evaluating the real risk for the dams in operation. We analyzed three different scenarios—initial reservoir level equal to maximum normal level, equal to a maximum conservation level, and following the probability distribution from the historical records. To do so, we presented a method applied to a gated-spillway dam located in the Tagus river basin. A set of 100,000 inflow hydrographs was generated through a Monte Carlo procedure, by reproducing the statistics of the main observed hydrograph characteristics—peak flow, volume, and duration. The set of 100,000 hydrographs was routed through the reservoir applying the Volumetric Evaluation Method as a flood control strategy. In order to compare the three scenarios, we applied an economic global risk index. The index combines the hydrological risk for the dam, linked to the maximum water level reached in the reservoir, during the flood routing, and the flood risk in the downstream river reach, linked to the discharge releases from the dam. The results showed the importance of accounting for the fluctuation of initial reservoir levels, for assessing the risk related to hydrological dam safety. Furthermore, a procedure to quantify the uncertainty associated with the effects of initial reservoir level on hydrological dam safety, has been proposed.

scholarly journals Stochastic Assessment of the Influence of Reservoir Operation in Hydrological Dam Safety through Risk Indexes

Proceedings ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 12
Author(s):  
Ivan Gabriel-Martin ◽  
Alvaro Sordo-Ward ◽  
Luis Garrote ◽  
Isabel Granados
Keyword(s):  
Probability Distribution ◽  
Flood Risk ◽  
Management Strategy ◽  
Flood Control ◽  
Evaluation Method ◽  
Risk Index ◽  
Reservoir Management ◽  
Dam Safety ◽  
Reservoir Level ◽  
Design Flood

Hydrological dam safety assessment methods traditionally assume that the reservoir is full while it receives the design flood. In practice, reservoir management strategy determines the probability distribution of reservoir levels at the beginning of flood episodes. In this study, we present a method to economically assess the influence of reservoir management strategy on hydrological dam safety and downstream flood risk. The method was applied to a gated spillway dam located in the Tagus River basin. A set of 100,000 inflow hydrographs was generated through a Monte Carlo procedure, reproducing the observed statistics of main hydrograph characteristics: peak flow, volume, and duration. The set of 100,000 hydrographs was routed through the reservoir applying the volumetric evaluation method as a flood control strategy. Three different scenarios were studied: Initial reservoir level equal to maximum normal level, equal to a maximum conservation level, and following the probability distribution of initial reservoir levels. In order to evaluate economically the influence of initial variable reservoir level and compare the three scenarios, a global risk index was applied. The index combines the hydrological risk for the dam, linked to the maximum water level experienced in the reservoir while the flood is routed, and the flood risk in the downstream river reach, linked to the discharge releases from the dam. The results highlighted the importance of considering the fluctuation of initial reservoir level for assessing the risk related to hydrological dam safety.

scholarly journals Probabilistic Model for Real-Time Flood Operation of a Dam Based on a Deterministic Optimization Model

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3206
Author(s):  
Víctor Cuevas-Velásquez ◽  
Alvaro Sordo-Ward ◽  
Jaime H. García-Palacios ◽  
Paola Bianucci ◽  
Luis Garrote
Keyword(s):  
Real Time ◽  
Optimization Model ◽  
Flood Control ◽  
Evaluation Method ◽  
Risk Index ◽  
Mixed Integer ◽  
Global Risk ◽  
Case Based Learning ◽  
Milp Model ◽  
Conventional Models

This paper presents a real-time flood control model for dams with gate-controlled spillways that brings together the advantages of an optimization model based on mixed integer linear programming (MILP) and a case-based learning scheme using Bayesian Networks (BNets). A BNet model was designed to reproduce the causal relationship between inflows, outflows and reservoir storage. The model was trained with synthetic events generated with the use of the MILP model. The BNet model produces a probabilistic description of recommended dam outflows over a time horizon of 1 to 5 h for the Talave reservoir in Spain. The results of implementing the BNet recommendation were compared against the results obtained while applying two conventional models: the MILP model, which assumes full knowledge of the inflow hydrograph, and the Volumetric Evaluation Method (VEM), a method widely used in Spain that works in real-time, but without any knowledge of future inflows. In order to compare the results of the three methods, the global risk index (Ir) was computed for each method, based on the simulated behavior for an ensemble of hydrograph inflows. The Ir values associated to the 2 h-forecast BNet model are lower than those obtained for VEM, which suggests improvement over standard practice. In conclusion, the BNet arises as a suitable and efficient model to support dam operators for the decision making process during flood events.

scholarly journals Inflow Flood Simulation and Risk Analysis of Cascade Reservoirs

2018 ◽  
Vol 246 ◽  
pp. 01106
Author(s):  
Jing Huang ◽  
Jiqing Li ◽  
Pengteng Liang
Keyword(s):  
Risk Analysis ◽  
Flood Control ◽  
Flood Routing ◽  
Three Gorges ◽  
Design Flood ◽  
Flood Simulation ◽  
Cascade Reservoirs ◽  
The Three Gorges ◽  
Flood Regulation ◽  
Risk Rate

The risk of flood control in cascade reservoirs reflects the possibility of unforeseen events in upstream reservoirs under certain space-time conditions during the operation of flood control. Using @RISK software and a stochastic simulation model to simulate the inflow flood of cascade reservoirs, the flood routing of cascade reservoirs and the risk analysis of the highest water level were carried out based on the flood regulation rules of Three Gorges-Gezhouba cascade reservoirs. The results of simulation calculations show that the risk rate of the Three Gorges-Gezhouba cascade reservoir is lower than its design flood standard, which can ensure the safety of flood control.

Risk analysis for flood-control structure under consideration of uncertainties in design flood

2010 ◽  
Vol 58 (1) ◽  
pp. 117-140 ◽  
Author(s):  
Shiang-Jen Wu ◽  
Jinn-Chuang Yang ◽  
Yeou-Koung Tung
Keyword(s):  
Risk Analysis ◽  
Flood Control ◽  
Control Structure ◽  
Design Flood

scholarly journals Multi-Ship Collision Avoidance Decision-Making Based on Collision Risk Index

2020 ◽  
Vol 8 (9) ◽  
pp. 640
Author(s):  
Yingjun Hu ◽  
Anmin Zhang ◽  
Wuliu Tian ◽  
Jinfen Zhang ◽  
Zebei Hou
Keyword(s):  
Decision Making ◽  
Decision Support ◽  
Risk Analysis ◽  
Real Time ◽  
Collision Avoidance ◽  
Evaluation Method ◽  
Risk Index ◽  
Collision Risk ◽  
Ship Collision ◽  
Risk Thresholds

Most maritime accidents are caused by human errors or failures. Providing early warning and decision support to the officer on watch (OOW) is one of the primary issues to reduce such errors and failures. In this paper, a quantitative real-time multi-ship collision risk analysis and collision avoidance decision-making model is proposed. Firstly, a multi-ship real-time collision risk analysis system was established under the overall requirements of the International Code for Collision Avoidance at Sea (COLREGs) and good seamanship, based on five collision risk influencing factors. Then, the fuzzy logic method is used to calculate the collision risk and analyze these elements in real time. Finally, decisions on changing course or changing speed are made to avoid collision. The results of collision avoidance decisions made at different collision risk thresholds are compared in a series of simulations. The results reflect that the multi-ship collision avoidance decision problem can be well-resolved using the proposed multi-ship collision risk evaluation method. In particular, the model can also make correct decisions when the collision risk thresholds of ships in the same scenario are different. The model can provide a good collision risk warning and decision support for the OOW in real-time mode.

Les évacuateurs de crues en labyrinthe : dimensionnement, fonctionnement, exemples et particularités

1995 ◽  
Vol 22 (5) ◽  
pp. 916-924 ◽  
Author(s):  
Nacer Eddine Zerrouk ◽  
Claude Marche
Keyword(s):  
Key Words ◽  
Flood Control ◽  
Experimental Studies ◽  
Flood Routing ◽  
Design Flood ◽  
Labyrinth Weir ◽  
Right Of Way ◽  
Attractive Option ◽  
Flow Diagrams ◽  
Calculation Procedures

The purpose of this paper is to demonstrate that labyrinth spillways can be a better option than rectilinear ones. The stages that have led to development of the labyrinth spillway are briefly reviewed as are applicable design and calculation principles. Discharge flow diagrams given by Hay and Taylor, Darvas, Lux and Hinchliff, and Magalhaes and Lorena for a trapezoidal labyrinth weir are compared. Calculation procedures and design diagrams were automated, making it possible to study flood routing through a labyrinth spillway and compare its performance to that of an equivalent rectilinear spillway. A real case was used for validation: routing through the trapezoidal labyrinth weir selected for the Keddara Dam in Algeria was compared with routing through the rectilinear spillway of the initial design. Dimensions, discharge values and expected maximum heights show calculated results agree with results of experimental studies of the structure and confirm that technically the labyrinth spillway is an attractive option. Labyrinth spillways can be particularly attractive for upgrading existing developments to satisfy more demanding design flood criteria in the limited right-of-way of an existing spillway. The Sainte Brigitte-des-Saults development in Quebec on the Nicolet Sud-Ouest River is a good case in point. Key words: flood control works, spillway, labyrinth weir, polygonal weir, nonrectilinear weir.[Journal translation]

Study on Flood Control Pre-Discharge Dispatching Scheme of Reservoir Based on Fuzzy Optimum Selection

2013 ◽  
Vol 353-356 ◽  
pp. 2641-2644
Author(s):  
Xiao Meng ◽  
Xian Bing Wu
Keyword(s):  
Flood Control ◽  
Risk Index ◽  
Fuzzy Optimization ◽  
Design Flood ◽  
Discharge Time ◽  
Model Method ◽  
Optimum Selection ◽  
Ex Ante ◽  
Objective Risk ◽  
Reliable Basis

Flood control dispatching of reservoir belongs to the ex-ante decision. This paper established the flood pre-discharge dispatching multi-objective risk index system and fuzzy optimization model method, taking Long Men reservoir as an example, to study the design flood pre-discharge scheme for different frequency, different frequency analysis of design flood pre-discharge flow and pre-discharge time, provide the reservoir flood pre-discharge scheme of different frequency flood and provide reliable basis for reservoir flood control pre-discharge dispatching.

Risk Analysis for Dam Safety Evaluation: Hydrologic Risk.

1996 ◽  
Author(s):  
Jery Stedinger ◽  
David C. Heath ◽  
Kay Thompson
Keyword(s):  
Risk Analysis ◽  
Safety Evaluation ◽  
Dam Safety

Research on Oil Depot Safety Evaluation Based on Dow Chemical Fire and Explosion Index Assessment Method

2013 ◽  
Vol 748 ◽  
pp. 1256-1261
Author(s):  
Shou Hui He ◽  
Han Hua Zhu ◽  
Shi Dong Fan ◽  
Quan Wen
Keyword(s):  
Production Management ◽  
Evaluation Method ◽  
Risk Index ◽  
Safety Evaluation ◽  
Assessment Method ◽  
Theoretical Ground ◽  
Potential Hazard ◽  
Process Unit ◽  
Safety Production ◽  
Fire And Explosion

At the present time, the Dow Chemical Fire and Explosion Index (F&EI) is a kind of risk index evaluation method that is comprehensively used in evaluating potential hazard, area of exposure, expected losses in case of fire and explosion, etc. As the research object to oil depot storage tank area, this article ultimately confirms establishing appropriate pattern of process unit as well as reasonable safety precautions compensating method, in order to insure the reasonableness of evaluating result, by means of selecting process unit, confirming material factor and compensating safety precautions, using F&EI method. This can provide the basis for theoretical ground in aspect of oil depot development and safety production management.

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