金沙江流域气温降水变化特性分析

Characteristics Analysis on Temperature and Precipitation Variation in Jinsha River

根据金沙江流域气温和降水资料,采用M ann-Kendall趋势分析、有序聚类、小波分析方法分析流域气温和降水的年际变化特征、趋势性、突变性和周期性。研究表明:(1)金沙江流域上游多年平均气温在0℃以下,年际变化稍大,下游多年平均气温在12℃左右,中游处于二者之间,且年际变化较小;流域大部分地区年均气温呈显著性升高趋势,气温升高主要发生在1980年以后,且普遍存在7～9年、14～15年和23～25年的近似周期,在1997、1992年和1986年发生突变;(2)金沙江流域降水丰富,干流年降水量自上游至下游逐渐增大,支流相对较均匀,且年降水年际变化较小;流域大部分地区年降水呈不显著的增加趋势,局部出现降水减少现象;普遍存在2～3年、7～8年和15年的近似周期;在1997、1993、1986年左右存在突变性。

According to the data of temperature and precipitation in Jinsha River analyzed by stochastic hydrology method,the annual variation and the tendency,mutation and periodicity of annual temperature and precipitation was reflected.The results show that： Firstly,the average annual temperature was below zero in upstream with interannual variation slightly,about 12℃ in downstream and between the two with smaller interannual variation in midstream.After 1980,the annual temperature increased observably,having the mutations period in 1997,1992 and 1986,and the period of 7 to 9 years,14 to 15 years,23 to 25years.Secondly,the abundant annual precipitation increased gradually from upstream to downstream in main stream,well-distributed in affluent basin with smaller interannual variation.It increased indistinctively in most areas and decreased in part with the period of 2 to 3years,7 to 8 years,and 15 years,also changing in 1997,1992 and 1986 suddenly.