Mann-Kendall 方法是一种非参数统计检验方法。非参数检验方法也称无分布检验，其 优点是不需要样本遵从一定的分布，也不受少数异常值的干扰，更是用于类型变量和顺序变 量，计算也比较方便。-Mann-Kendall method is a non-parametric statistical tests. Non-parametric test method, also known as non-distribution test, the advantage is not required to comply with certain distribution of samples, it is not subject to interference few outliers, it is the type of variable and variable order to calculate more convenient.