澜沧江流域水文气象要素变化特征分析

以澜沧江流域为对象,采用气候倾向率、MK检验、Pearson相关性分析等方法,分析1958-2015年气温和降水的空间分布、年内分配及演变趋势,揭示径流演变的驱动要素。结果表明:澜沧江流域气温空间分布不均,上游温度低降水少,下游温度高降水多;降水和径流年内分配不均,主要集中于夏秋两季,径流峰值比降水峰值滞后一个月;1958-2015年气温呈上升的趋势,降水和径流呈下降趋势;2005年为径流出现突变的年份,年径流减少21.5%;气温升高、降水量减少对径流减少有一定贡献;气温与径流的相关性较差,降水径流相关性于2005年之后变差,尤其是夏秋两季。

Characteristics analysis of hydrometeorological elements in Lancang River Basin

Taking Lancang River Basin as a study object, the spatial distribution, intra-annual distribution and evolution trends of temperature and precipitation between 1958 to 2015 were analyzed by using climate tendency rate, MK-test and Pearson correlation analysis, and the diving factors of runoff evolution were revealed. Results indicate that the spatial and intra-annual distribution of the temperature and precipitation is uneven. The upstream has low temperature and few rainfall, while the downstream is on the contrary. The precipitation and runoff distributed uneven in the year, mainly in the summer and autumn. The runoff peak comes one month later than rainfall peak. From 1958 to 2015, the trend of temperature is rising and the trends of rainfall and runoff are falling. Runoff mutation occurred in 2005 and the annual runoff decreased by 21.5%. Runoff reduction is mainly associated with rising temperature and decreasing rainfall. Temperature is weakly correlated to runoff. Precipitation was well correlated to runoff before 2005 while poorly correlated after 2005, especially in summer and fall.