Time Scale Variation of the Yellow River Ice in the Inner Mongolia Section Using Wavelet Analysis

Abstract

Due to the comprehensive effects of thermal factor, power factor, river course factor and human factor, indicated that ice information, such as flow ice date, frozen river date, breakup date of river ice and ice thick and so on presents complex change, this article attempts to analyze ice information whether has varied characteristic in the time criterion with the wavelet method. Through analyzing wavelet transform coefficient and wavelet variance in Inner Mongolia section, and the time series rules are summarized of ice characteristic. At the same time, wavelet variational figures and wavelet transformation frequency variance figures are drawn of Inner Mongolia station. Research results show that flow ice date sequence have obvious frequency variance extreme value of about 12 years criterion, therefore said that flow ice date exists about 12 years cycle, frozen river date and breakup ice date sequence have not remarkable frequency variance extreme value, but there is no obvious peak in about 6 years place of frozen river date frequency variance and in about 12 years place of breakup ice date frequency variance, which explained that frozen river date and breakup ice date sequence exist weak cycle.