中文摘要：

使用水文统计和交叉小波方法对西江流域1961-2005年径流变化特征及其与气象要素的多时间尺度的关联性进行分析。结果表明,径流量总体呈现减少的变化趋势,可能是人类活动引起流域内蒸发和入渗增加,使径流对降水的响应减弱造成的,径流丰枯变化基本与降水的波动相一致。气温对径流的显著作用主要集中在1990-2000年3-5 a周期上,径流对气温变化的响应时间为6-12个月;降水与径流在大部分时频域中呈同相相位变化,其相互作用主要集中在1992-2003年3-4 a和1980-2000年11-12 a周期上;大气环流变化对径流的影响主要集中在1965-1975年2-3 a及1993-2000年3-5 a周期上,对径流的影响可能是通过对区域降水影响实现的,径流对前一次环流变异响应时间为6-12个月,对后一次响应时间较快,时间的差异可能是下垫面的改变引起流域产汇流机制变化造成的。

英文摘要：

Using hydrological statistics and cross wavelet transform analysis, the variation characteristics of the runoff of the Xijiang River and the relation between the meteorological factors and the runoff in multi-time scales are detected in this research. The analysis indicates that the annual runoff decreases, which might be due to the weaken response of runoff to precipitation caused by increasing of evaporation and infiltration effected by human activities. The annual runoff fluctuation shows good correspondence with the precipitation. The cross wavelet analysis revealed that the impact of temperature to river flow occurred in the circle of 3-5 years in 1990-2000, in which the runoff shows lagging of 6-12 months to the temperature variation; the in-phase rela-tions between the precipitation and river flow are found in almost all the time-frequency domains, good coher-ence can be found in the circle of 3 to 4 years between 1992 and 2003 and 11 to 12 years in 1980-2000; the im- pact of abnormal climate on runoff mainly occurred in the circle of 2 to 3 years in 1965-1975 and 3 to 5 years in 1993-2000, the impacts to the runoff variation might be carried out by the influence on the precipitation in the basin, the lag time between runoff variation and abnormal climate change event is 6 to 12 months in1965-1975 while equated almost to zero in 1980-2000, this phenomenon might be caused by the changing of runoff production process effected by the changing of land use.