石羊河流域出山口径流特征及其与山区气候变化相关关系分析

The Characteristics of Runoff from Mountainous Watershed and Its Correlation of Climatic Change in Shiyang River Basin

采用Mann-Kendall与Morlet小波变换对石羊河流域出山口近50年（1956年-2005年）的径流量进行趋势和周期性分析，结果显示石羊河流域出山口年径流量总体呈现平稳波动走势，近50年来处于历史较低时期。该径流存在30年以上尺度的年际变化和年代变化，以及22年左右的尺度、14年-15年尺度、约12年尺度和10年以下尺度的周期变化；中长尺度周期变化突出，30年表现为第一主周期。石羊河流域出山口年径流的周期变化与鸟鞘岭站年降水量和年均气温周期基本上都能在同一周期上下浮动，其中出山口年径流量与鸟鞘岭山区年降水量相关系数为0．61，说明地表径流量主要是由山区降水补给；年径流量与山区年均气温变化呈0．28的反相关，说明该流域近50年来出山口径流与山区气温呈反比，即径流量随年均气温上升而减少，相关性暂时不十分明显。

Based on the data of annual runoff from the eight meteorological stations of mountainous watershed, the Mann-Kendall method and Molet wavelet transform is applied to the tendency characteristics of total runoff in the resent 50 years in the Shiyang River Basin. The results show that 1 ） the general variance tendency of annual runoff is fluctuated, and keeping lower quantity of historic periods ; 2） The periods of runoff and points of abrupt change at different time scales are analyzed. There are multi-scaled period changes for runoff, which are mid-long periods of 30years, 22years, 14 years 15years, and 12years and below 10years of short periods, especially the periods which are longer than 14years. The wavelet variance verification also indicates that the first main period of the runoff of mountainous watershed in the Shiyang River Basin is 30years, and 22years and 15years are the second and third period respectively; 3）Then we also compared the total runoff of mountain watershed with climate factors of Wushaoling which station is in the mountain headstream area, such as precipitation and temperature, the data record that the correlation coefficient of annual runoff and precipitation variation over the upper reaches in the Shiyang River Basin is 0.61, which indicates precipitation is the main water recharge of the runoff. At the same time, the correlation coefficient of annual runoff and mean temperature variation is - 0.28, and there is an inverse proportion between them, which means runoff is much more when temperature becomes lower, but not in evidence; 4） The reasons that correlation between climate changes and runoff is particular are too difficult to understand. One explains maybe temperature varieties can cause shape of precipitation change, and improve runoff recharge of precipitation instantly. At one time, these periodic rules of these three parts are similar, probably according to the movement of celestial body, such as solar activities. It also affected by other factors which land use/cover changes, and activity of human being. Finally, some problems to be solved in future are briefly analyzed.