近百年来东平湖沉积通量变化与环境  

Sedimentary Flux Variation and Environment of Dongping Lake During the Last Century

作　　者：陈影影[1] 陈诗越[1] 姚敏[2] 刘加珍[1] 张菊[1] 

机构地区：[1]聊城大学环境与规划学院,山东聊城252059 [2]中国科学院南京地理与湖泊研究所,南京210008

出　　处：《沉积学报》2010年第4期783-789,共7页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(批准号:40772209);山东省社科规划项目(编号:07DJGZ08)资助

摘　　要：根据210Pb、137Cs法建立的东平湖现代沉积年代序列,结合沉积物粒度与烧失量变化特征以及黄河变迁与流域人类活动的特点,分析探讨了1889年以来东平湖沉积通量的变化。研究表明,百年来东平湖沉积环境不稳定,沉积通量变化较大:1889～1938年,沉积通量较高且基本稳定,1938～1965年,沉积通量逐年下降,1965～2000年,沉积通量整体较低且基本稳定,2000年以来,沉积通量呈逐年上升趋势。早期的高沉积通量与东平湖作为黄河自然滞蓄洪区有关,后期由于人类活动(湖区治理、黄河水利工程建设等)控制了黄河水的自然倒灌,导致了沉积通量的下降并趋于稳定,近期沉积通量的上升是湖区经济活动增强的反映。Dongping lake is located in the southwest of Shandong Province,it is the second lake in size in Shandong Province and is also an important flood control reservoir at the lower reaches of the Yellow River.Based on the modern sedimentary age sequence of the Dongping Lake which was established according to ^210Pb and ^137Cs methods,the sedimentary flux changes since 1889 were estimated and the reasons were analyzed and discussed.By using ^137Cs method,three obvious peaks were observed in the core and the sedimentary flux was 0.145g·cm^-2·a^-1 by ^137Cs time marker（1963）.The CRS model of 210Pb dating was used to caculate the sedimentary flux at different time intervals since 1989,the results showed that the sedimentary flux changed greatly,indicating that the sedimentary environment of Dongping Lake was unstable more than a century： from 1989 to 1938,the average sedimentary flux was high and stable,which was about 0.292 g·cm^-2·a^-1;decreased year by year during 1938 to 1965,with an average of 0.213 g·cm^-2·a^-1;was low and stable and showed a good agreement with the 137Cs method from1965 to2000;and started increasing year by year since 2000,with an average of 0.167 g·cm^-2·a^-1.The early high depostion flux maybe relevant to the fact that Dongping Lake has acted as a natural flood storage basin of the Yellow River,and the latter as a result of human activities（lake governance,water conservancy construction of the Yellow River,and so on） which controled the natural flooding of the Yellow River and led to a decline in sedimentary flux and tend to be stable,while the recent rise is a reflect of the increased economic activity.In this paper,the spatial distribution regularity of sedimentary flux and the relationship between the sedimentary flux and nature and human activities were explored so as to reveal the evolutionary history of the sedimentory environment of Dongping Lake more than a century and offer valuable basic information for protection and sustainable exploration of the Dongping Lake.

关 键 词：^210PB ^137CS 沉积通量 沉积环境 东平湖 

分 类 号：P512.2[天文地球—地质学]