Method for quantitatively analyzing underground water numerical simulation uncertainty based on information entropy

Abstract

The invention provides a method for quantitatively analyzing underground water numerical simulation uncertainty based on information entropy. The method comprises the steps that the information entropy of predictive variable probability distribution is adopted as the uncertainty of a variable, and according to the predictor formula and information entropy theory of a Bayesian model averaging method, the underground prediction uncertainty is decomposed into a model structure, model parameters and the overlapped uncertainty among various concept model prediction distributions. The uncertainty of each probability distribution type random variable can be measured, the defect that a traditional variance method can only measure normal distribution is overcome, and the application range of quantitative uncertainty analysis is enlarged; the underground water numerical simulation uncertainty breaks up into model parameters, the model structure and the overlapped uncertainty, and the defect that the overlapped uncertainty cannot be described through the traditional variance method can be overcome; the model parameter uncertainty is defined as the difference obtained by subtracting the model overlapped uncertainty from the sum of various concept model interior (parameter) uncertainty weights, and therefore the uncertainties are described more accurately and reasonably.

Description

technical field [0001] The invention relates to an uncertainty quantitative description method, in particular to a groundwater numerical simulation uncertainty quantitative analysis method. Background technique [0002] Numerical simulation of groundwater is affected by many factors, and the sources of uncertainty in simulation (prediction) results can usually be summarized as follows: (1) Uncertainty of model parameters, that is, uncertainty caused by unreasonable setting of model parameters; ( 2) The uncertainty of the model structure (conceptual model), that is, the uncertainty caused by the unreasonable generalization of the hydrogeological conceptual model. The uncertainty of model parameters has first been noticed by groundwater workers, but the uncertainty of conceptual models is usually not given enough attention. Generally, a single hydrogeological conceptual model is used to represent the groundwater system, ignoring the possibility of the existence of other model ...

AI Technical Summary

Problems solved by technology

[0016] The traditional variance method is simple in principle and easy to operate, but it can be found in the application process: (1) The concept of variance cannot reasonably describe the uncertainty of certain types of probability distributions, such as multimodal distributions, and this type of probability distribution is common in Predicted distribution of groundwater numerical simulation; (2) The variance method defines the weight of the variance of the predicted distribution of each conceptual model as parameter uncertainty, and defines the variance of the mean value of the predicted distribution of each conceptual model as the uncertainty of the model structure, which cannot describe similar structures Overlap Uncertainty Between Conceptual Models

Therefore, there are certain limitations and unreliability when using the variance method to quantitatively analyze the uncertainty of groundwater numerical simulation.

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