基于隐马尔可夫模型的安徽省降水特征研究

Research of Precipitation Characteristics in Anhui Province Using Hidden Markov Model

通过隐马尔可夫模型(Hidden Markov Model,HMM)对安徽省降水规律及特征进行分析模拟,以验证其在区域性降水方面的适用性。采用包含4个隐式状态的HMM对省内6个主要城市的多年日降水数据序列进行拟合。用贝叶斯信息准则(Bayesian Information Criterions,BIC)确定模型中隐式状态数量,用Baum-Welch算法训练得到最优模型参数,用Viterbi算法确定模型中最优状态序列。采用上述方法模拟安徽省6个城市在1960—2009年夏季共50个时段的降水情况。前40 a用于模型分析训练,后10 a用于模型验证及评价,结果表明HMM能更好地模拟降水特征,具有较高的实用性。

The laws and characteristics of precipitation in Anhui Province were analyzed and simulated using the Hidden Markov Model （HMM） to verify its applicability in regional precipitation. HMM with four implicit states was employed to fit the daily precipitation data sequence of many years in six major cities in the province. Bayesian Information Criterion was adopted to determine the implicit state quantity, the Baum-Welch algorithm to train and obtain the optimal model parameters, and the Viterbi algorithm to determine the optimal sequence of the model states. The above methods were adopted to simulate the precipitation in the summer of 1960-2009 in six cities of Anhui Province. The first 4-decade was for model training and analyzing, and the later 1 decade for model valida- tion and evaluation. Results showed that HMM is of high practicability by better simulating rainfall characteristics.