雅砻江流域径流极值变化规律及影响因素分析

Changes of Extreme Runoff and the Influencing Factors in Yalong River Basin

利用雅砻江流域雅江和洼里站逐日径流资料,采用Mann-Kendall检验法、有序聚类法、突变检验(Pettitt)法和小波功率谱法对流域极值流量的趋势性、突变性及周期性进行分析。结果表明,雅江和洼里站年最大流量序列均有不显著增加趋势,年最小流量序列则均有不显著减小趋势;雅江站年最大、年最小流量序列和洼里站年最大流量序列均存在1~2 a和6 a周期,洼里站年最小流量序列为1~2 a周期。雅江站年最大日流量在1998年发生突变,与流域极值降水变化有一定关系。

Based on the daily runoff data from the Yajiang and Wali hydrological stations in Yalong River Basin, the MannKendall test, sequential cluster analysis, Pettitt test and wavelet spectrum method are used to analyze the change trend, abrupt change and periodic characteristics of extreme runoff in Yalong River Basin. The results show that,( a) the annual maximum flows at Yajiang and Wali stations all exhibit an insignificant increasing trend, while the annual minimum flows display an insignificant decreasing trend;( b) the annual maximum and minimum flow at Yajiang Station and the annual maximum flow at Wali Station both have 1-2-year and 6-year cycles, and the minimum flow at Wali Station has 1-2-year cycle. The abrupt change point for extreme flow at Yajiang Station occurs in 1998, which is related to the change of extreme precipitation in the basin.