To investigate the impacts of urbanization processes,water conservancy project and human activities on the evolution trend of river water environment,sediment core (CH1) was collected in the Changhu Reservoir,Wengjiang River basin,in September 2015.Measurements of sediment unsupported 210Pb (210Pbex) activity,TOC,TN,TP content,δ13C and particle size were conducted.The results showed that the sedimentary record of CH1 was obtained in about 58years.The average contents of TOC,TN and TP in the sediment core were 1.07％ (range:0.65％～1.66％),0.12％(0.08％～0.20％),438.00mg/kg (294.74～675.44mg/kg).Vertical distribution characteristics of TOC,TN and TP in the sediment core of the reservoir showed that before 1957,the TN,TP and TOC content of sediment core exhibited a slowly increasing trend,the content initially increased and then decreased in 1957 to 1991,and generally increased from 1991 to 2015.However,the storm flood occurred in 1994 significantly changed the sediment particle composition,thus decreasing TOC,TN and TP content.In combination with characteristics of C/N and δ13C,the source of organic matter was mainly identified as the mixture of terrestrial and aquatic sources,and the dam construction mainly resulted in the input of terrigenous organic matter in the reservoir area.%为了探究城市化进程、水利工程建设等人类活动对河流水环境演变趋势的影响,于2015年9月在广东省滃江长湖水库采集沉积物柱状样品(CH1),测试沉积物剩余210Pb(210pbex)活性、TOC、TN、TP含量、δ13C及粒径大小.结果表明,CH1的沉积历史约58a,沉积物TOC、TN和TP的平均含量分别为:1.07％(范围:0.65％～1.66％)、0.12％(0.08％～0.20％)、438.00mg/kg (294.74～675.44mg/kg);沉积物TOC、TN、TP含量在3个时段的分布特征:1957年之前,均呈现缓慢增加的趋势,在1957～1991年先减小后增加,在1991～2015年总体呈现出升高的趋势;1994年的暴雨洪水改变了沉积物的粒径特征进而减小了TOC、TN、TP的含量;结合C/N和δ13C特征辨析了沉积物有机质的来源主要为陆源和水相的混合源,大坝的修建是导致沉积物(24cm～20cm)有机质偏向陆源的一个重要原因.
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