金沙江下游及三峡段水文气象因子演变与响应的分析

Temporal Analysis of Hydrological and Meteorological Factors in Downstream of Jinsha River and Three Gorges Reach of Yangtze River

对金沙江下游及三峡段3个水文站1954~2008年径流序列和2个气象站1951~2008年降雨、气温序列运用滑动平均法和Mann-Kendall法进行趋势性检验,利用有序聚类法、均值检验法分析突变性及小波分析法进行周期性诊断,并应用Pearson法对径流、降雨和气温的相关关系进行研究。研究表明：（1）研究区径流量的年内分配不均匀性和年际变化不显著。（2）金沙江下游段屏山站的径流量呈上升趋势,并在1997年发生突变,但该区域宜宾站的降雨量呈下降趋势并在1991年发生突变;三峡段寸滩站和宜昌站的径流量呈下降趋势,分别在1968年和2005年发生突变,同时该区域沙坪坝站的降雨量呈上升趋势并在1961年和1995年发生突变。（3）径流和降雨时间序列都存在小于10a的主周期以及20a以上的次周期。（4）各水文站夏季径流量受同期降雨量和同期气温的共同影响,而秋季径流量受前期气温的影响最大。

Using the mean monthly runoff at the 3 hydrology stations from 1954 to 2008 as well as the precipitation and tempera- ture series at the 2 meteorology stations from 1951 to 2008 in the downstream of the Jinshajiang River and Three Gorges Reach, this paper investigated the change tendency of hydrological and meteorological factors with moving average method and Mann- Kendall rank correlation test, and examined the mutability and periodicity with sequential clustering analysis, mean value test method and wavelet analysis. In addition, the sensitivity of runoff to precipitation and temperature change was analyzed. The results show that： （1） Inner-annual distribution and inter-annual variation of runoff in the study area is not significant. （2） The runoff at the Pingshan Station in the downstream of the Jinshajiang River indicates an uptrend and an abrupt change in 1997, meanwhile, the precipitation at the Yibin Station reflects the opposite trend with a mutation point in 1991. Similarly, the annual runoff at the hydrology stations in the Three Gorges Reach presents a downtrend and abrupt changes in 1968 and 2005, while the precipitation at the Shapingba Station shows an increasing trend with obviously mutation points in 1961 and 1995. （3） Series of runoff and pre- cipitation all show main cycles less than 10 years and secondary cycles over 20 years. （4） Runoff in summer is jointly influenced by precipitation and temperature in the corresponding period, and foregoing temperature mostly impacts runoff in autumn.