| 引用本文: | 柴轶凡,张灿,孔令阳,赵成.云南错恰湖两百年来气候环境变化与重金属污染.湖泊科学,2018,30(6):1732-1744. DOI:10.18307/2018.0624 |
| CHAI Yifan,ZHANG Can,KONG Lingyang,ZHAO Cheng.Climatic changes and heavy metal pollution over the past 200 years recorded by Lake Cuoqia, southwestern Yunnan Province. J. Lake Sci.2018,30(6):1732-1744. DOI:10.18307/2018.0624 |
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| 云南错恰湖两百年来气候环境变化与重金属污染 |
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柴轶凡1,2, 张灿1,2, 孔令阳3, 赵成1
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1.中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室, 南京 210008;2.中国科学院大学, 北京 100049;3.云南师范大学旅游与地理科学学院, 高原地理过程与环境变化云南省重点实验室, 昆明 650500
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| 摘要: |
| 高海拔地区由于特殊的自然环境对气候变化和营养输入的响应十分敏感.在人类活动逐渐加强的背景下，高山湖泊高分辨率的沉积物记录了人与自然相互作用的演变过程.选取云南西北部典型高山湖泊——错恰湖，获取长度37 cm的连续湖泊沉积序列，基于铅铯测年法得到年代深度模型，并对湖芯样品进行总有机碳、总氮及正构烷烃的多指标测定和元素测量，结合气象监测数据探讨分析错恰湖的有机质来源和流域环境演化特征.根据气候代用指标的变化，两百年来错恰湖泊环境及区域气候演化可以分成4个主要阶段：1807-1900年：湖泊水位上升、湖面扩大，有机质丰度下降，有机质以外源贡献为主，内源比例上升；1900-1950年：湖泊水位开始下降、湖面收缩，有机质丰度下降，外源有机质来源增加；1950-1982年：湖泊水位下降、湖面进一步收缩，有机质丰度下降，外源输入比例继续增加；1982-2007年：湖泊水位下降、湖面收缩，有机质含量上升且以陆源输入为主，同时内源贡献比例开始增加.在元素测定结果中，人类活动对应了湖泊沉积重金属含量变化的3个阶段：1950年以前，重金属含量低且稳定，可视作自然背景阶段，人类影响忽略不计；1950年以后，湖泊流域工农业逐渐发展，人为干扰凸显；直到1982年以后，冶炼工业的进步加强了重金属的污染态势，并通过大气传输沉降被湖泊沉积物记录.错恰湖沉积记录的分析讨论在总结该区域气候环境演化历史的同时，加深了对气候人类活动湖泊生态系统相互作用过程的理解，为高山湖泊响应人类活动影响提供了证据. |
| 关键词: 错恰湖 高山湖泊 湖泊水位 正构烷烃 重金属 |
| DOI：10.18307/2018.0624 |
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| 基金项目:国家自然科学基金项目（41472315）和中国科学院南京地理与湖泊研究所引进海外人才项目（Y3BR013064）联合资助. |
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| Climatic changes and heavy metal pollution over the past 200 years recorded by Lake Cuoqia, southwestern Yunnan Province |
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CHAI Yifan1,2, ZHANG Can1,2, KONG Lingyang3, ZHAO Cheng1
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1.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China;2.University of Chinese Academy of Sciences, Beijing 100049, P. R. China;3.Key Laboratory of Plateau Lake Ecology and Global Change, School of Tourism and Geography, Yunnan Normal University, Kunming 650500, P. R. China
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| Abstract: |
| High-altitude areas are sensitive to environmental changes due to their unique natural condition. In the context of the increasing human activities, sediments of alpine lakes could record the processes of human-nature interaction. Here we present multi-proxy records, including total organic carbon, total nitrogen and n-alkanes along with elementals, inferred from a 37-cm-long sediment core collected from a small alpine lake (Lake Cuoqia) in northwestern Yunnan Province, China. Together with instrumental data and other published regional records, we divide environmental changes into four stages over the past 200 years:ca. 1807-1900:increased lake level and expanded surface area, declined organic matter abundance, and exogenous mainly contributions of organic matter with growing endogenous contributions; ca. 1900-1950:slightly declined lake level and decreased surface area, decreased abundance of organic matter, and slightly increased exogenous organic matter; ca. 1950-1982:further dropped lake level and shrank lake surface, declined abundance of organic matter, and increased exogenous organic matter; ca. 1982-2007:further decreased lake level and surface area, increased organic matter content which was dominated by terrestrial inputs with the addition of endogenous contributions. We also divide the industrial pollutions into three stages based on the heavy metal results:before ca. 1950:very low heavy metal concentration indicating natural background without anthropogenic influences; ca. 1950-1982:beginning of industrial pollutions; after ca. 1982:abruptly increased heavy metal pollutions due to the development of ore industry. As Lake Cuoqia has a very small catchment without any human activity and industry, the heavy mental pollutions are likely transported through atmospheric circulation. Our records indicate the considerable environmental fluctuations over the last 200 years, and suggest that industry pollutants could be transported and influence the remote high-altitude areas. |
| Key words: Lake Cuoqia alpine lakes lake level n-alkanes heavy metals |
