:: Przegląd tematu - mbt zapatos Flood risk analysis of reservoir opera

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(3) Monte Carlo method (MC method)
Reservoir operation runoff process is generally subject to the Markov process (Markov process). Markov process is a class of variables and interrelated effects of non-stationary stochastic process, its basic features are not Aftereffect. Therefore, the state transition probability of Markov processes can be used to inquire Reservoir in the risk of interaction between the risk variable rate issues. Markov process has been successful with Ascertaining the reliability of reservoir regulation scheme of the generation rate (guaranteed rate).
④ discrete state combination method

When the reservoir operation
System is an important method of modern scientific research. It is the overall departure from the system by studying the various aspects of risk between the main house, the risk environment, the relationship between various elements, the main risk of the relationship with the risk environment, the target system to determine risk, the establishment of mathematical model of the whole system,tory burch sale, solving the most optimal risk decision, a risk benefit mechanism, risk control and risk management. The method is widely applicable, in theory is more scientific, the ideal,zapatos nike, but the application is difficult.
③ Risk Analysis Method
Basic principle of this method is to first give the risk estimates of discrete variables; then combined in accordance with principles of probability estimates from these discrete outcome to inquire the size of its possibilities. The scope of the Act is exhaustive, when the risk of more variables, and each discrete state the number of risk variables is large,mbt zapatos, there is However, the number of variables in the risk of less variable within each risk occurrence or non-occurrence of two states that the distribution of the three cases, analysis of risk in this way is very effective.
2.3 qualitative and quantitative methods of analysis
B i for the reservoir drainage, A release of water reservoirs for the storage of water and reservoir water level, then P (B i / A) is known reservoir inflow and reservoir water level conditions, the probability of reservoir drainage. Similarly, can the risk of reservoir drainage rates calculated.
Risk according to the characteristics of reservoir operation, the following describes 4 methods:
Keywords: Reservoir flood risk analysis methods

② calculated based on Bayesian risk ratio
1
Reliability and risk are two complementary concepts, the research began in the former 30 to 40 years of this century, with the probability of machinery and equipment maintenance problems; research began in the latter 50 years, first used by the military production sector proposed. To the early 80s, reliability and risk analysis theory and gradually form a rich, diverse methods, a more complete theoretical system of the edge of science.
2.3.1 Qualitative Risk Analysis Qualitative Risk Analysis is primarily used to measure very small risk to the risk of the subject. Commonly used survey methods, matrix analysis and Delphi method. Delphi Rand Corporation in the United States first proposed advisory body, mainly by means of the relevant expert knowledge, experience, and risk judgments to be estimated and analyzed. Some of the water resources system analysis of uncertainty is difficult to calculate, so the risk of reservoir operation decision-making method has practical value.

2 general method of risk analysis 〔 5 ~ 10 〕
2.1 a combination of static and dynamic methods of investigation
① probability distribution function of a typical hazard rate
This method is widely used in Western countries, investment risk analysis, the basic idea is to project the economic effects of the risk analysis of each variable separately by random sampling, and then random values of each variable to calculate the economic evaluation values for each variable so that a sample taken randomly to calculate the economic evaluation can be a random value, the economic effect evaluation index to make their relationships to achieve the cumulative probability curve, you need to repeat the experiment many times, and with the stochastic risk variable increases,mbt zapatos, the number of repeated simulation also increased, requires the use of computer calculations. In addition, this method can not solve all the interaction between risk variables, and required to give all the risk
[2] Next [/b]
Flood risk analysis Reservoir Review

Abstract: has a variety of risk analysis methods, they are considerations, the input information, computation and the application of different objects, for flood risk analysis, reservoir operation, This area should be combined with the specific circumstances of the region, features, comparison and improvement of existing methods.
Let B 1 , B 2 , ..., B n is a complete set of mutually exclusive set of events, that is, B i mutually exclusive, there are Σ B i = Ω, and suppose P (B i )> 0, then for any event A, Let P (A)> 0, there are:

FD i = σ i / MX = σ i / μ i
P
With the mathematical probability distribution characteristics, such as standard deviation σ or σ - semi-standard deviation, may indicate the size of the risk. σ or σ - the greater the risk the greater the smaller the contrary. Because the probability distribution of the more dispersed, the probability of actual results from the greater expectations.
2.2 a combination of micro and macro systems approach
Reliability in Water Resources Engineering
Where, P (B i ) for the prior probability of (known) or the prior probability; P (A / B i ) is associated with the prior probability The conditional probability (known); P (B i / A) is under the conditions of the event A occurs, causing B i the probability of occurrence for the posterior probability (unknown .)
Survey is conducted by actual survey of the main risks and risk control information. Combination of dynamic and static investigation is necessary to understand the status of the subject, but also to understand the past, but also summarize, predict its future. Water systems used for investigation is not appropriate for some issues, such as reservoir operation risks.
Σ = (DX) 1 / 2 = ( (X i -MX) 2 / ( n-1)) 1 / 2 or σ - = (DX) 1 / 2 = ( (X i -MX) 2 P (X i )) 1 / 2
Σ is the only statistic X i <MX> MX. With σ, σ - compared the size of the risk is simple, clear concept, but the σ - for a physical quantity of the absolute amount, when two very different expectations of the ICP when comparable difference, and compared the results may not be accurate. In order to overcome with σ - comparable bad enough, you can compare the relative amount of parameters as the relative degree of risk is defined as the amount of FD i , with the expectation that the ratio of standard deviation ( coefficient of variation):
In reservoir operation, affect the risk of the main risk of the uncertainty variables (or random variables) most of the probability distribution of the typical subject, such as the triangular distribution, Weibull distribution, normal distribution, Gaussian distribution, gamma distribution, Ⅲ distribution and so on. Therefore, the probability distribution density function with integral indicators can be analyzed and calculated decision to get a reliable rate or hazard rate index, the accuracy of the method is simple and can basically meet the requirements.
Probability theory and mathematical statistics is the study of reliability and risk of reservoir operation rate of the most powerful tools, such as in the past generation of reservoir operation and irrigation guarantee rate calculated to ensure that rates are built on the foundations. The basic theory and methods suitable for solving the risk rate calculation.
(2) the risk based on Markov process analysis
Degree of risk FD i greater the greater the risk, and vice versa. Degree of risk is different from the hazard rate, the former value can be greater than 1, which can only be less than or equal to 1.
(1) based on probability theory and mathematical statistics, risk analysis
apply the concept of early risk, such as reservoir operation, it has long been guaranteed rate with the power generation, irrigation guarantee rate method to evaluate concepts such as the merits of the reservoir operation strategy. Risk Analysis in the late 70's to infiltrate the field of water resources research and water resources development in the United States in the first of applications. ASI was established in 1984, NATO Advanced Research Institute, specializing in water resources engineering reliability and risk studies and proposed water resources engineering reliability and risk research framework and systems theory, method and evaluation. The current world water resources engineering and water system operation risk decision risk analysis have attached great importance, and carried out extensive research 〔 2,3 〕 . However, as water is an important branch system - reservoir operation, and analysis of its concept of risk was raised 80 years, research has just begun.
Recent years, many domestic scholars have studied 〔 4 〕 .学 INTERNATIONAL combination of methods to estimate the probability of such use of the reservoir downstream <LABEL class=lb onclick=risk analysis model; von Equality of the flood water level on flood control and power of influence through risk-benefit comparison quantitatively reasonable flood control level; Hsieh Tsung Po and other analysis of reservoir flood risk calculation in the hydrology, water flow and water storage capacity relationships are not certainty, of a reservoir flood control application of comprehensive risk rate model; Chuan Liang range analysis method to flood control risk assessment; Wang Germany 〔 5 〕 to establish a reservoir flood risk in real time scheduling model that considers the benefit of flood control reservoirs and reservoir risk downstream two goals, and pre-storage reservoir in the discussion of benefits and risks of the necessity and on the basis of the main difficulties, first proposed a kinds of risk rate is calculated, and then propose a target cost and risk was pre-reservoir water level fuzzy control model and its solution; Tianfeng Wei and put forward joint probability distribution function based on typical risk decision making. Li Guofang and Tanai Ji by frequency analysis method, <LABEL class=lb onclick=With the moment method and entropy perfected, can be entropy, probability theory and the combined risk estimates, risk estimates to establish the maximum entropy model. Li Jiqing other 〔 6 〕 using AHP, the economic system is divided into flood water conservancy, power generation, irrigation (water) effective subsystem , identification of risk factors in two risk portfolio, the establishment of maximum entropy model, the risk characteristics by the system cost.
2.3.2 Quantitative Risk Analysis Quantitative Risk Analysis is the main risk of using mathematical tools to study the relationship between the number of features and changes, determine the risk ratio (or degree).
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