| 引用本文: | 张云峰,张振克,王万芳,张凌华,陈影影,徐华夏.江苏省石梁河水库高分辨率沉积速率变化及环境意义.湖泊科学,2014,26(3):473-480. DOI:10.18307/2014.0319 |
| ZHANG Yunfeng,ZHANG Zhenke,WANG Wanfang,ZHANG Linghua,CHEN Yingying,XU Huaxia.The changes of sedimentation rates and the environmental significance based on high resolution cores in Shilianghe Reservoir, Jiangsu Province. J. Lake Sci.2014,26(3):473-480. DOI:10.18307/2014.0319 |
|
| 摘要: |
| 石梁河水库是江苏省最大的人工湖泊.开展水库沉积速率研究,对认识水库环境变化具有重要意义.本文对石梁河水库沉积物岩芯粒度组成特征进行了分析,表明沉积物以黏土质粉砂和粉砂质黏土为主,从底部向上呈明显的变细趋势,并记录了1970年的强降雨事件.采用137Cs同位素测年分析,得到1963年和1986年两个时标.通过石梁河水库的沉积年代序列,推算出平均沉积速率:1963 1970年为10.85 cm/a,1970 1986年为3.81 cm/a,1986 2005年为1.32 cm/a.对比粒度沉积特征和流域降水记录,粗颗粒物质和降雨量的变化趋势基本相同,沉积物粒度组成特点直接反映了沉积时的降水、水动力搬运强度等信息.在河川来水来沙、坝前水位变化和地形等条件下,石梁河水库表现为三角洲淤积,且沉积速率逐渐变缓,符合水库淤积的一般规律.此外,石梁河水库上游建设的众多大型水库,拦截了大量泥沙,也使得沉积速率呈现减小趋势. |
| 关键词: 石梁河水库 沉积速率 137Cs测年 环境变化 |
| DOI：10.18307/2014.0319 |
| 分类号: |
| 基金项目:湖泊与环境国家重点实验室开放基金项目(2010SKL004);国家自然科学基金项目(41071006)联合资助 |
|
| The changes of sedimentation rates and the environmental significance based on high resolution cores in Shilianghe Reservoir, Jiangsu Province |
|
ZHANG Yunfeng, ZHANG Zhenke, WANG Wanfang, ZHANG Linghua, CHEN Yingying, XU Huaxia
|
|
Key Laboratory of Coast and Island Development of Ministry of Education, School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing 210093, P. R. China
|
| Abstract: |
| Shilianghe Reservoir is the largest artificial lake in Jiangsu Province. It is very important to study the sedimentary rates of the reservoir in order to understand the environmental change in the river basin. 137Cs technique is used to date a sediment core collected from Shilianghe Reservoir. Two distinct 137Cs peaks are identified in the core, which are ascribed to the abundant fallouts occurring in 1963 and 1986. The grain size analysis indicates that clayey silt and silty clay are the main sedimentary types with a trend of gradually fining from the bottom to the top, and revealed a heavy rainfall event in 1970. Sedimentary rates of the core can be divided into several distinctive stages:10.85 cm/a from 1963 to 1970, 3.81 cm/a from 1970 to 1986, and 1.32 cm/a from 1986 to 2005. Furthermore, the environment significances were explained by using the sedimentary records. Through the comparison between grain size characteristics and historical precipitation records, the changes of coarse sediments contents and rainfall are of the similar trend, which directly reflects the information such as the intensities of rainfall and hydrodynamic transportation. Sedimentary environment of the Shilianghe Reservoir is typical deltaic under the controls of runoff and sediment transport, variations of water level and local terrain. Therefore, sedimentary rates are becoming low gradually following the general law of reservoir siltation. Furthermore, human activities have influenced the changes of sedimentary rates, such as construction of large reservoirs in the upstream of the river. |
| Key words: Shilianghe Reservoir sedimentation rates 137Cs dating environmental change |
