摘要
融雪径流是三江源地区水资源重要的组成部分。随着全球气候变化的加剧,融雪径流时间在发生变化,对于该区年径流量及其季节分配将产生重要影响。本文通过计算流量质心时间(Timing of the Center of Massfor Flow)来表示融雪径流的开始时间,利用时间序列的趋势分析方法,发现在1957年～2000年间,三江源地区主要水文站的融雪径流时间都有提前的趋势,其中澜沧江源的香达站、黄河源唐乃亥站以及长江源的直门达站融雪径流时间的提前趋势在95%的置信水平上表现显著,从变化幅度来讲,香达站融雪径流时间提前最大,大约有10天左右,而沱沱河提前最少,约为4天左右。通过相关性分析,认为三江源地区融雪径流时间与年径流量存在正相关关系,即融雪径流时间越晚年径流量越大,这种关系在直门达、吉迈以及唐乃亥站都表现显著。融雪径流时间的提前同时也会影响径流的季节分布,即会伴随着春季径流增加、夏秋季径流的减少,而与冬季径流的关系在各站不一。最后,对三江源地区融雪径流时间与大尺度气候信号的关系进行了探讨,分析了三江源地区融雪径流时间的可预测性。该研究的开展将会为三江源地区水资源的管理和预测提供科学借鉴。
Snowmelt runoff is one of the most important components in water resources across the source regions of the Yangtze River, Yellow River and Lancang River （Sanjiangyuan）. Timing of snowmelt runoff may be influenced by climate change. The variations in timing of snowmelt may thus impact annual runoff and its seasonal allocation. Timing of the Center of Mass for Flow （CT） was used as a proxy of timing of snowmelt runoff in this study as it is difficult to measure timing of snowmelt runoff in field. Trend analyses showed that, in the period 1957-2000, the snowmelt runoff in Sanjiangyuan has shown a trend to become earlier with 95% confidence level in Xiangda Station of the Lancang River, Tangnaihai Station of the Yellow River and Zhimenda Station of the Yangtze River. The Xiangda station showed the largest change while the Tuotuohe station showed the smallest one. Correlation analysis performed in this study demonstrated that there is a positive correlation between the timing of snowmelt runoff and the annual runoff in the Zhimenda Station, Jimai station and Tangnaihai station during the study period. This suggests that the earlier shift of snowmelt runoff timing may lead to decreases in annual runoff in Sanjiangyuan. Under the condition of earlier shift of snowmelt runoff timing, runoff observed in these stations increased in spring while decreased in summer and autumn. However, there was no obvious change in winter. The relationship between the timing of snowmelt runoff and the large-scale climate signals was examined. To evaluate the utility of large-scale climate signals for predicting timing of snowmelt runoff, the lag correlation between timing of snowmelt runoff and ENSO, PDO were calculated. It was found that timing of snowmelt runoff is negatively correlated with the PDO in August of the previous year, showing a correlation with 95% confidence level （i.e. Xiangda station （r=-0.359, P= 0.017）, Tangnaihai station （r=-0.313, P=0.029）, and Zhimenda station （r =-0.314, P=0.028））. It was al
出处
《资源科学》
CSSCI
CSCD
北大核心
2009年第10期1704-1709,共6页
Resources Science
基金
科技部国际合作重点项目:"青海省三江源国家级自然保护区水资源预测系统研究"
关键词
三江源
融雪径流时间
趋势分析
径流
Source regions of the Yangtze River, Yellow River and Lancang River （Sanjiangyuan）
Timing of snowmelt runoff
Trend analysis
Runoff.
