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矿井涌水量时间序列包含矿区地下水系统长期演化的信息。根据相空间重构技术,首先采用自相关函数法和虚假邻点法,确定最佳延迟时间和最佳嵌入维数。重构相空间后,再利用Wolf提出的从单变量时间序列中提取Lyapunov指数的方法。该文分别计算了湖南湘中涟邵煤田大水岩溶矿区4个矿井涌水量时间序列的Lyapunov指数,按照混沌特性判别准则,4个矿井涌水量时间序列均存在明显的混沌特性。这不仅为今后矿区地下水系统的非线性研究提供了理论依据,而且为矿井涌水量预测模型的选择提供了有力的依据。
Mine influx time series contains information on the long-term evolution of the groundwater system in the mining area. According to the technique of phase space reconstruction, the optimal delay time and the optimal embedding dimension are firstly determined by the method of autocorrelation function and the pseudo-neighbors method. After reconstructing the phase space, we use Wolf’s method to extract the Lyapunov exponents from the univariate time series. In this paper, the Lyapunov exponents of time series of four mine shafts in Da Shui karst mine in Lianshao coalfield, Hunan province, are calculated respectively. According to the criteria of chaotic characteristics, the chaotic characteristics of four mine shafts are obvious. This not only provides a theoretical basis for the nonlinear study of underground mine water system in future, but also provides a strong basis for the selection of mine water inflow prediction model.