近800年来巢湖沉积物营养元素富集特点及其环境演变意义  

Characteristics of Nutrient Elements' Enrichment in Deposits of Chaohu Lake and Its Indication for Environmental Change During Last 800 Years

作　　者：贾铁飞[1] 张卫国[2] 俞立中[2] 余铁桥[1] 

机构地区：[1]上海师范大学地理系,上海200234 [2]华东师范大学河口海岸学国家重点实验室,上海200062

出　　处：《地理科学》2009年第6期893-899,共7页Scientia Geographica Sinica

基　　金：国家自然科学基金项目(批准号:40771201);上海市教育委员会重点学科建设项目"地理学与城市环境"(批准号:J50402)资助

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800a来的环境变化划分为4个沉积时期：沉积年代1177～1271a A．D．是气候暖湿高湖面阶段；1271～1747a A．D．，总体上为湿润环境下有机质快速积累阶段，其中1477～1747a A．D．显示“小冰期”气候特点；1747～1865a A．D．气候开始转暖，湖面上升；1865a 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 era, 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 charac- teristics 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. ④1865 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.

关 键 词：巢湖 环境演变 营养元素分析 历史时期 

分 类 号：P318.4[天文地球—固体地球物理学] P352[天文地球—地球物理学]