流域径流演变多时间尺度特征探讨

采用Morlet子波变换等分析方法,结合逐月实测径流资料分析了大沽夹河流域径流演变的多时间尺度变化特征.结果表明,流域径流演变过程存在明显的多时间尺度特征,具有18～32 a,8～17 a和3～7 a的3类尺度的周期变化规律.流域径流的演变过程在一定程度上受降水控制,但其变化趋势和降水的变化趋势并不能完全吻合,同时还受人类活动的影响.在不同的时间域和时间尺度内,气候变化和人类活动对流域径流变化的影响同时存在.

Discussion on Multiple Timescales Characteristics of Runoff Variation in Basin

Based on the monthly runoff data observed by hydrological stations in Dagujia River Basin which is regarded as a typical basin in Shandong Peninsula,the multiple time scales characteristics and driving forces of annual runoff are studied by use of wavelet analysis and other mathematical methods. The results suggested that there were obvious multiple time scales in annual runoff variation process and the major periods of the time series were about 28 years, 14 years and 4 years. The variation process of annual runoff was controlled by the precipitation to a certain extent, while the variation trends of runoff and precipitation were not consistent. It was also affected by human activities. At different time periods and scales,the affection on annual runoff variation by climate change and human activities existed at the same time. Annual runoff change was mainly affected by climate change before 1980s and the human activities were the main driving forces since 1981 year.