由于气候变化和人类活动的影响,水文要素的分布形式和参数可能在统计意义上产生了变异。为了揭示水文要素在时间尺度上的变异关系.将乌力吉木仁河梅林庙测站1956-2000年的逐月径流资料,按照不同的时间尺度划分为季度、汛/非汛期和年径流序列,利用水文变异诊断系统分别对其进行变异诊断,并查阅相关文献得出剧烈的人类活动是导致变异的主要原因。通过归纳不同时间尺度的变异诊断结果得出,对于按照季度尺度划分的径流序列,不同月份径流量占年径流量的比例是影响季度变异的主要因素,在变异程度方面,第一季度的变异程度最大,而第三季度的变异程度则最小;对于汛/非汛期尺度划分的径流序列,其变异则受所包含月份的综合影响,且月径流量比例系数越大,其影响程度也越大;对于年径流序列.其变异则主要受到第三季度或汛期径流的影响。
Under the influence of climate change and human activities, alterations may happen to the distribution regulations and parameters of hydrological elements in time scale statistics. In order to uncover the relationship of hydrological element alterations on time scale, the monthly runoff series at the Meilinmiao station in the third grade Wulijimuren River from 1956 to 2000 were divided into different time scales, i.e. seasonal, flood seasonal, non-flood seasonal and annual runoff series, then the hydrological alteration diagnosis system was used to analyze the alteration, and by looking up for references, the main reason caused the alteration is extensive human activities. Based on alteration diagnosis results in different time scales, it was concluded that, in respect of seasonal scale of runoff series, the main factor that influence the seasonal alteration is the proportion of different monthly runoff to the annual runoff, the degree of alteration in the first season is the biggest and the third season is the smallest. In the other aspect of flood and non-flood seasonal scale runoff series, the alteration condition is influenced comprehensively by all the months included, and the bigger monthly runoff proportion, the greater the influence. To the annual runoff series, it is mainly influenced by the third season or the flood season.