塔里木河流域水化学组成分布特征

Study on Hydrochemical Components of River Water in the Tarim River Basin,Xinjiang,China

于2010年6月对塔里木河干流及主要支流地表水进行水化学采样,共设25个点采集50个样品。分析表明:塔里木河干流水体中阳离子Na++K+>Ca2+>Mg2+,与南北侧支流Na++K+>Mg2+>Ca2+存在显著差异,但均以Na++K+为主,阳离子浓度分别占干流、南北侧支流的68.6%、62.6%和62.5%。与1965年对应采样点同月份水化学成分相比,塔里木河流域主要可溶性离子浓度增幅较大,整体平均增加8.0倍,尤其是Cl-达21.7倍,这可能是近年来塔里木河流域气温上升降水增加等自然因素,间接促进降水过程中水化学侵蚀地表可溶性物质所致。同时,流域内工农业快速发展,生活污水、工农业废水大量排放到塔里木河,这可能是影响塔里木河水质变化的重要因素之一。

In this study,some surface water samples were collected from the mainstream and main distributaries of the Tarim River Basin in June 2010 to analyzed the hydrochemical components.The ionic concentrations of Koxkar glacier meltwater collected from the headwaters of the Tarim River were compared with those of the Heihe River,the second longest continental river in China.The results revealed that the main basic ionic concentrations in the Tarim River Basin were higher than those in the Heihe River.The concentrations of cations of mainstream of the Tarim River were in an order of Na＋＋K＋Ca2＋Mg2＋,which were significantly different from those of its main distributaries,i.e.Na＋＋K＋Mg2＋Ca2＋,and the main basic cations were Na＋ and K＋ but not Ca2＋.The Na＋＋K＋ concentrations of the mainstream and the south and north distributaries accounted for 68.6%,62.6% and 62.5% of the total basic cationic concentrations respectively.The mean ionic concentrations（except NO-3） of the north distributary were lower than those of the south one.Compared with the values in 1965,the ionic concentrations in the Tarim River Basin were significantly increased by 8 times in average,and especially,the Cl-concentration was as high as 21.7 times of that in 1965,which were possibly related to the increase of both air temperature and precipitation in the Tarim River Basin in recent years.Moreover,river water in the Tarim River Basin was polluted due to the rapid industrial development and sewage discharge.