A method for quantifying coupling degree of drought and heat wave based on time-varying moment model and decomposing driving force

Abstract

This invention discloses a method for quantifying the coupling degree of drought-heat wave and decomposing its driving forces based on a time-varying moment model (PMOE). It constructs a time-varying moment-constrained maximum entropy distribution (POME) model for heat wave and drought sequences, expressing the key Lagrange multipliers of the PMOE model as a linear function of climate indices and urbanization factors to characterize the time-varying characteristics of univariate marginal distributions. Based on pseudo-observations, a time-varying Copula model considering physical driving factors is constructed. Through the optimal combination of various parameter structures, the dynamic evolution of the interdependent structure between drought and heat waves is characterized. By calculating and comparing risk impact indicators under multiple models, the influence of climate change and human activities on the coupling degree of drought-heat waves is quantified and separated. This invention achieves simultaneous characterization of the dynamic evolution and non-stationary characteristics of complex extreme events, and effectively identifies and decomposes the contributions of key physical driving factors, providing a scientific basis for dynamic risk assessment and adaptive countermeasure formulation for regional complex events.

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