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

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.

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 461 ◽  
Author(s):  
Ivan Gabriel-Martin ◽  
Alvaro Sordo-Ward ◽  
Luis Garrote ◽  
Isabel Granados

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.


2018 ◽  
Vol 7 (4.34) ◽  
pp. 473
Author(s):  
Nurul Afiqa Adila Zakaria ◽  
Ahmad Shakir Mohd Saudi ◽  
Mohd Khairul Amri Kamarudin ◽  
Muhammad Hafiz Md Saad

The objective of this research is to determine the correlation of selected hydrological variables, to analyzed the significance factors influenced the occurrences of flood, to propose the flood control limit system and establish new flood risk index model in Lenggor River Basin based on secondary data derived from Department of Drainage and Irrigation (DID). Application of Chemometric technique such as Spearman’s Correlation Test, Principle Component Analysis, Statistical Process Control and Flood Risk Index created the most efficient results. Result shows water level has strong factor loading of 0.78 and significant for flood warning alert system application. The Upper Control Limit (UCL) for the water level in study area is 33.23m while the risk index for the water level set by the constructed formula of flood risk index consisting 0-100. The results show 20.6% classified as High Risk Class with index range from 70 and above. Thus, these findings are able to facilitate state government to come out with a comprehensive plan of action in strengthening the flood risk management at Lenggor River basin, Johor.  


2018 ◽  
Vol 7 (4.34) ◽  
pp. 473
Author(s):  
Nurul Afiqa Adila Zakaria ◽  
Ahmad Shakir Mohd Saudi ◽  
Mohd Khairul Amri Kamarudin ◽  
Muhammad Hafiz Md Saad

The objective of this research is to determine the correlation of selected hydrological variables, to analyzed the significance factors influenced the occurrences of flood, to propose the flood control limit system and establish new flood risk index model in Lenggor River Basin based on secondary data derived from Department of Drainage and Irrigation (DID). Application of Chemometric technique such as Spearman’s Correlation Test, Principle Component Analysis, Statistical Process Control and Flood Risk Index created the most efficient results. Result shows water level has strong factor loading of 0.78 and significant for flood warning alert system application. The Upper Control Limit (UCL) for the water level in study area is 33.23m while the risk index for the water level set by the constructed formula of flood risk index consisting 0-100. The results show 20.6% classified as High Risk Class with index range from 70 and above. Thus, these findings are able to facilitate state government to come out with a comprehensive plan of action in strengthening the flood risk management at Lenggor River basin, Johor.  


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3206
Author(s):  
Víctor Cuevas-Velásquez ◽  
Alvaro Sordo-Ward ◽  
Jaime H. García-Palacios ◽  
Paola Bianucci ◽  
Luis Garrote

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.


2013 ◽  
Vol 353-356 ◽  
pp. 2641-2644
Author(s):  
Xiao Meng ◽  
Xian Bing Wu

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.


2018 ◽  
Vol 7 (4.34) ◽  
pp. 370
Author(s):  
Nurul Afiqa Adila Zakaria ◽  
Ahmad Shakir Mohd Saudi ◽  
Mohd Khairul Amri Kamarudin ◽  
Muhammad Hafiz Md Saad

The objective of this research is to determine the correlation of selected hydrological variables, to analyzed the significance factors influenced the occurrences of flood, to propose the flood control limit system and establish new flood risk index model in Lenggor River Basin based on secondary data derived from Department of Drainage and Irrigation (DID). Application of Chemometric technique such as Spearman’s Correlation Test, Principle Component Analysis, Statistical Process Control and Flood Risk Index created the most efficient results. Result shows water level has strong factor loading of 0.78 and significant for flood warning alert system application. The Upper Control Limit (UCL) for the water level in study area is 33.23m, while the risk index for the water level set by the constructed formula of flood risk index consisting 0-100. The results show 20.6% classified as High Risk Class with index range from 70 and above. Thus, these findings are able to facilitate state government to come out with a comprehensive plan of action in strengthening the flood risk management at Lenggor River basin, Johor.  


2007 ◽  
Vol 56 (4) ◽  
pp. 87-95 ◽  
Author(s):  
A. Winterscheid

It is now commonly accepted that the management of flood risks has to be fulfilled within an integrated framework. About two decades ago flood risk was managed from a limited perspective predominantly by means of structural measures aimed at flood control. In contrast integrated flood risk management incorporates the complete management cycle consisting of the phases prevention, protection and preparedness. In theory it is a well described concept. In the stage of implementation, however, there is often a lack of support although a consistent policy framework exists. Consequently, the degree of implementation must be rated as inadequate in many cases. In particular this refers to the elements which focus on preparedness and prevention. The study to which this paper refers emphasises the means and potentials of scenario technique to foster the implementation of potentially appropriate measures and new societal arrangements when applied in the framework of integrated flood risk management. A literature review is carried out to reveal the state-of-the-art and the specific problem framework within which scenario technique is generally being applied. Subsequently, it is demonstrated that scenario technique is transferable to a policy making process in flood risk management that is integrated, sustainable and interactive. The study concludes with a recommendation for three applications in which the implementation of measures of flood damage prevention and preparedness is supported by scenario technique.


2013 ◽  
Vol 748 ◽  
pp. 1256-1261
Author(s):  
Shou Hui He ◽  
Han Hua Zhu ◽  
Shi Dong Fan ◽  
Quan Wen

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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