Trend Analysis of the Runoff Variation in Lhasa River Basin in Tibetan Plateau during the Last 50 Years
Trend Analysis of the Runoff Variation in Lhasa River Basin in Tibetan Plateau during the Last 50 Years
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青藏高原拉萨河流域近50年径流变化趋势分析
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Liu Linshan
中科院分区：
文献类型：
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作者：
Liu Linshan
以青藏高原拉萨水文站以上的拉萨河流域为研究对象，利用拉萨、唐嘎两个水文站的水文资料和当雄、拉萨、唐嘎三个气象站的气象资料，分析了1956-2003年拉萨河流域年平均径流量和月平均径流特征。利用非参数Mann-Kendall检验和Pettit-Mann-Whitney变点统计量，分析了1956-2003年间径流和气候的变化趋势和变点。利用多元线性回归分析了径流与气候变化的相关性。主要研究结果如下：(1)1956~2003年的年平均径流量具有波动大、趋势正的特点，有两个转折点(1970年前后和1980年代初)，此后径流呈增加趋势，近20年来增加幅度较大。除年平均径流量外，冬半年(11~4月)和夏半年(5、7、9月)的月平均径流量呈正趋势。(2)研究区气候变化趋势与径流变化趋势基本一致，但引起径流变化的主导气候因素明显。夏半年降水是影响年平均径流量和月平均径流的主要因素，冬季温度是影响年平均径流和月平均径流的主要因素。
Taking the Lhasa River Basin above Lhasa hydrological station in Tibetan plateau as a study objective, the characteristics of the annual and monthly mean runoff in 1956-2003 were analyzed, which were based on the hydro-data of the two hydrological stations (Lhasa and Tangga) and the meteorological data of the three meteorological stations (Damxung, Lhasa and Tangga). The trends and the change-points of runoff and climate from 1956 to 2003 were detected by using the nonparametric Mann-Kendall test and Pettitt-Mann-Whitney change-point statistics. The correlations between the runoff and climate change were analyzed by using multiple linear regression. The major results could be summarized as follows: (1) The annual mean runoff in 1956~2003 is characterized by a great fluctuation and a positive trend with two change-points (around 1970 and the early 1980s), after which the runoff tended to increase and was increasing intensively in the last 20 years. Besides the annual mean runoff, the monthly mean runoff with a positive trend is in winter half year (from November to April) and summer half year (May, July and September). (2) The trends of the climate change in the study-area are generally consistent with the trend of the runoff, but the leading climate factors which aroused the runoff variation are distinct. Precipitation is the dominant factor influencing the annual and monthly mean runoff in summer half year, while temperature is the primary factor in winter.