中文摘要：

森林与水的关系一直是生态学和水文学研究的热点（Calder,2007;Laurance,2007;Wang et al.,2011）。一般认为,森林植被具有调节径流的作用,但森林对径流的影响在不同研究之间存在很大差异（郭明春等,2005;魏晓华等,2005;Chirino et al.,2006;索安宁等,2007;王金叶等,2012）。径流变化受森林植被、流域面积和降水等多种因素影响,

英文摘要：

In this paper, runoff processes of a small forested watershed in upper reaches of Lijiang River were in situ monitored and the relationships between runoff and influencing factors were studied from January 2009 to December 2011. The results showed that the precipitation distributed irregularly within a year and there were obvious differences in precipitation amount among years, which resulted in great runoff fluctuation and inter-annual variation in Lijiang River. Summer runoff accounted for 63.2% of the whole year＇s and winter runoff accounted for 9.2% . The runoff coefficient of the whole watershed was 0. 664 2. The precipitation effect on river runoff was accumulated with multiple rainfall events, which resulted in a lag of peak runoff behind the precipitation. Runoff period is usually longer than the precipitation＇s. The runoff would extend to 20 clays for 18 days＇ continued rainfall. The impact of rainfall on runoff decreased in non-linear with the extension of time after rainfall event. The accumulation of lagged runoff can reduce the function of forest on hydrological regulation and might result in large runoff under light rainfall in rain season.