三峡水库成库初期丰水期水环境化学特征

Characteristics of Water Environmental Chemistry in Flood Season in Incipient Three Gorges Reservoir

于2003年9月8～15日三峡水库成库后,利用航测的方法对三峡水库11个点位的部分水环境化学指标进行测试,结果表明金属及非金属离子浓度比成库前普遍增高。阳离子以钙为主,阴离子以硫酸根为主;重金属中Pb、Cd含量高,各点位平均值仅能达到Ⅴ类水质标准(GB3838-2002),其余重金属浓度均优于Ⅱ级标准。调查区域营养盐浓度较高,其中TN各监测点均超过国家地表水环境质量标准Ⅲ类水。成库后叶绿素a含量增加显著,变化范围在1.58～7.35mg/m3,平均浓度为4.69mg/m3,但水库区域水体总体上处于中营养水平。利用系统聚类方法,水环境化学指标有明显的地域分布特征。

The characteristics of water environmental chemical in the Three Gorges reservoir were determined by cruise during 8th to 15th September 2003 with 11 sites, after it became dam. The results indicated concentration of main iron was more high than before dam. The main cation was calcium and main anion was SO_4^(2-). The pollution of heavy metal was different. Concentration of Cu, Zn, Ni, Co were low and Pb, Cd were high, which only can reach the national surface water body quality standard Ⅴ(GB3838-2002).The restes of heavy metal were excelled water body quality standard Ⅱ.Concentration of nutrient was high. The concentration of nitrogen was exceed the national surface water body quality standard Ⅲ. After dam, chlorophyll a ranged from 1.58 to 7.53 mg/m^3.The average concentration of chlorophyll a was 4.69 mg/m^3 at surface layer. Which was increased than before. Water body was the degree of mesotropher. Using the method of system cluster, it showed there was distinct area distribution characteristics which could dispart three clusters.