长江源区1978—2009年径流极值序列变化趋势分析简

 基于长江源区控制站沱沱河和直门达1978—2009年径流观测资料,采用相关分析法和Mann-Kendall法对两站的32 a的径流极值的变化趋势进行了详细分析。结果表明两站在近32 a中径流极值均有增加的趋势,但是沱沱河径流极大值增加趋势显著,直门达河径流极大值增加趋势不显著;两站径流极大值变化相关性显著。其主要原因是气候暖湿化趋势,地表植被变化以及降雨增多。分析结果对制定三江源保护规划,保护流域水资源,预防洪水发生和应对河流枯水变化也具有重要的参考价值。

Variation Trend of Extreme Runoff Series in the Source Region of Yangtze River from 1978 to 2009

The observed runoff data at Tuotuo river and Zhimenda river hydrometric stations in the source region of Yangtze River from 1978 to 2009 are analyzed through Mann-Kendall test and Relevant Analysis method to research the runoff sequence variation. Results show that the maximum annual runoff at both stations has an increasing trend. The maximum runoff increased remarkably in Tuotuo river but unobvious in Zhimenda river. Significant correlation was found between the maximum runoff variation at these two stations, which suggests that the variation of runoff extremum from 1978 to 2009 is mainly affected by warm and wet climate,vegetation coverage variation, and the increase of precipitation.The research result could be of great value for the planning of river source protection, water resource protection, flood prevention and dry season response.