中天山典型内陆河流域水化学时空特征分析

基于2011—2013年不同季节乌鲁木齐河流域6个站点52组地表水化学的测试结果,结合流域气象水文资料,利用水化学分析方法和SPSS统计软件分析了乌鲁木齐河流域地表水化学时空变化特征、地表水各离子间相关性以及流域水化学特征的控制因素。结果表明:(1)乌鲁木齐河流域地表水总体矿化度较低,水体呈弱碱性。(2)流域地表水化学具有明显的季节变化趋势即早春融雪季、春末夏初季和秋季融雪季TDS值偏高,夏季TDS值低;同时也表现出较明显的年际差异性:多雨的年份地表水TDS值较低,少雨的年份地表水TDS值较高。(3)控制地表水体的主要离子为HCO_3~-,Ca~(2+),SO_4~(2-),离子质量浓度大小依次为HCO_3~-Ca~(2+)SO_4~(2-)Cl-Na+Mg~(2+)K+CO_3~(2-);不同季节控制水体的主要离子具有差异性:枯水期河水呈Ca~(2+)-HCO_3~-型;丰水期河流离子浓度受降水、冰川水的稀释影响离子浓度低,呈Ca~(2+)-HCO_3~--SO_4~(2-)型。(4)站点1到站点2河水中SO_4~(2-)浓度突然升高,主要是由于此段河水的含水层中分布有石膏夹层,石膏夹层释放了大量硫酸和氯酸。(5)通过对地表水水化学过程的分析显示控制流域地表水化学过程的主要影响因素为水岩交互运动。

Analysis of Temporal and Spatial Variation of Hydrochemical Characteristics of the Typical Inland River in the Middle of Tianshan Mountains

Based on the results of water chemistry of six stations in Urumqi River Basin in different seasons of 2011-2013,we analyzed the temporal and spatial characteristics of surface water chemistry in Urumqi River Basin by using water chemistry analysis method and SPSS statistical software in combination with hydrological data.The results show that:(1) the TDS of Urumqi River is lower and the water is slightly alkaline;(2) water hydrochemical characteristics varied over the years,TDS is lower in summer than that in early spring,early summer and autumn;(3) the control ions of the surface water are HCO3-,Ca2+,SO42-,the icon concentrations decrease in the order:HCO3-＞Ca2+ ＞SO42-＞Cl-＞Na+ ＞Mg2+ ＞K+ ＞CO32-;the main ions changed with years:Ca2+ and HCO3 are the main ions in dry season;while Ca2+,HCO3 and SO42-start to dominate in wet season for the dilution of abundant water;(4) the SO42-concentration suddenly rises in site 1 to site 2 due to the release of sulfuric acid and chloric acid in the gypsum horizon of the river segment;(5) the conclusion indicates that water-rock interaction movement is the main factor controlling the surface water hydrochemical properties.