摘要
通过对巢湖CH1孔沉积物进行年代学、粒度和营养元素(TOC、TN、TP、C/N比值)分析,可将巢湖近800 a来的环境变化划分为4个沉积时期:沉积年代1177~1271 a A.D.是气候暖湿高湖面阶段;1271~1747 a A.D.,总体上为湿润环境下有机质快速积累阶段,其中1477~1747 a A.D.显示"小冰期"气候特点;1747~1865 a A.D.气候开始转暖,湖面上升;1865 a A.D.至今,气候转干旱。1880′s以来的TOC、TN非自然水平富集,1660′s以来的TP非自然水平富集,是巢湖历史时期开始出现富营养化的征兆。
According to an analysis of the age data,granularity and magnetic in deposits of Chaohu Lake,and based on the foundation of chronological studying pole,core CH1 could be divided into 4 sedimentary chronological sections during the last 800 years: ① 1177 A.D.to 1271 A.D.,matched along with the records in deposits of the depth from 141 cm to 125 cm,is proven to be a wet /warm period and the lake level became higher.② 1271 A.D.to 1747 A.D.,matched along with the records in deposits of the depth from 125 cm to 44 cm,is proven to be a stage in which the organic matter accumulated in a general wet environment.From 1477 A.D.to 1747 A.D.in this stage,the records in deposits of the depth from 90 cm to 44 cm,reflect the variable characteristics of climate during the Little Ice Age(LIA) in eastern China,which indicates a general wet environment despite of some dry/cold alternative action during the period,including the drought maximum of the oscillation in 1747 A.D.③ 1747 A.D.to 1865 A.D.,matched along with the records in deposits of the depth from 44 cm to 24 cm,the last 100 years,still stayed in the LIA,but the climate of Chaohu Lake became warmer and the lake level uplifted.④ 1865 A.D.to the present,matched along with the records in deposits of the depth from 24 cm above,is proven to be a dry period and climate became drier. After the Enrichment Indices of the chemical elements and mineral nutrients content in the last 800 years are calculated by taking normalization,it is seen that the TOC/TN has increased with unnatural levels since the 1860s,while the TP has enriched with unnatural levels since the 1660s.These facts can reflect the environmental change impacted by human activities,and is also the evidence of the beginning of eutrophication during the history epoch in Chaohu Lake.
引文
[1]Anderson D E,Goudie A S,Parker A G.Global Environmentsthrough the Quaternary[M].Oxford:University,2007.
[2]翟秋敏,李容全,郭志永.坝上高原安固里淖粒度年纹层与环境变化[J].地理科学,2002,22(3):331~334.
[3]Dearing J A,Jones R T,Shen J,et al.Using multiple archives tounderstand past and present climate?human?environmentinteractions:the lake Erhai catchment,Yunnan Province,China[J].Journal of Paleolimnology,2007,31,LO1512,doi:10.1007/s10933-007-9182-2.
[4]李容全,赵烨,邱维理.中国新生代地理学的进展[J].地理科学,1999,19(4):364~367.
[5]申洪源,朱诚,贾玉连.太湖流域地貌与环境变迁对新石器文化传承的影响[J].地理科学,2004,24(5):580~585.
[6]曹建廷,王苏民,沈吉,等.近千年来内蒙古岱海气候环境演变的湖泊沉积记录[J].地理科学,2000,20(5):391~396.
[7]于世永,朱诚,王富葆,等.太湖流域全新世气候-海面短期震荡事件及其对新石器文化的影响[J].地理科学,2000,20(4),331~336.
[8]陆敏,张卫国,师育新,等.太湖北部沉积物金属和营养元素的垂向变化及其影响因素[J].湖泊科学,2003,15(3):213~220.
[9]贾铁飞,戴雪荣,张卫国,等.全新世巢湖沉积记录及其环境变化意义[J].地理科学,2006,26(6):706~711.
[10]王心源,张广胜,张恩楼,等.巢湖湖泊沉积记录的早-中全新世环境演变研究[J].科学通报,2008,53(增刊I):132~138.
[11]朱诚,张强,张芸,等.长江三角洲长江以北地区全新世以来人地关系的环境考古研究[J].地理科学,2003,23(6):705~712.
[12]杨则东,晁玉珠,褚进海,等.巢湖淤积及其对水患形成的环境影响遥感分析研究[J].地质灾害与环境保护,2005,16(1):53~57.
[13]Appleby P G,Nolan P J,Gifford D W.et al.210Pb dating by lowbackground gamma counting[J].Hydrobiologia,1986,143:21-27.
[14]姚书春,李世杰.巢湖富营养化过程的沉积记录[J].沉积学报,2004,22(2):343~347.
[15]侯立军,陆健健,刘敏,等.长江口沙洲表层沉积物磷的赋存形态特征及生物有效性[J].环境科学学报,2006,26(3):488~494.
[16]Meyers P A.Preservation of elemental and isotopic source identi-fication of sedimentary organic matter[J].Chemical Geology,1994,114(3-4):289-302.
[17]吴莹,张经,张再峰,等.场景悬浮颗粒物中稳定碳、氮同位素的季节分布[J].海洋与湖沼,2002,33(5):546~552.
[18]Grove J M.Little Ice Ages:Ancient and Modern[M].London:Routledge,2004.
[19]金章东,王苏民,沈吉,等.湖泊沉积物Sr同位素记录的小冰期[J].科学通报,2002,47(19):1512~1517.
[20]王绍武,叶瑾林,龚道溢.中国小冰期的气候[J].第四纪研究,1998,(1):54~64.
[21]Williams T P,Bubb J M,Lester J N.Metal accumulation withinsalt marsh environments:a Review[J].Marine Pollution Bulle-tin,1994,28(5):277-290.
[22]Zhang J,Liu C L.Riverine composition and estuarine geochemis-try of particulate metals in China-weathering features,anthropo-genic impact and chemical fluxes[J].Estuarine,Coastal andShelf Science,2002,54:1051-1070.
[23]魏复盛,陈静生,吴燕玉,等.中国土壤环境背景值研究[J].环境科学,1991,12(4):12~19.
[24]王心源,吴立,张广胜,等.安徽巢湖全新世湖泊沉积物磁化率与粒度组合的变化特征及其环境意义[J].地理科学,2008,28(3):548~553.
[25]杨艳丽,史学正,于东升,等.区域尺度土壤养分空间变异及其影响因素研究[J].地理科学,2008,28(6):788~793.
[26]曹隆恭.肥料史话[M].北京:中国农业出版社,1981.
目录