青藏高原东缘梯度带大气CO2含量与岩溶发育相关性初探  

A preliminary study on correlation of atmospheric CO 2concentration and karst development in the eastern margin ofQinghai-Tibet plateau,China

作　　者：许模[1] 毛邦燕[2] 张广泽[2] 康小兵[1] 漆继红[1] 李潇[1] 易磊 杨四福 XU Mo;MAO Bangyan;ZHANG Guangze;KANG Xiaobing;QI Jihong;LI Xiao;YI Lei;YANG Sifu(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;The Second Engineering Group Co.,Ltd.of China Railway,Chengdu 610031,China)

机构地区：[1]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),成都610059 [2]中铁二院工程集团有限责任公司,成都610031

出　　处：《成都理工大学学报（自然科学版）》2020年第6期724-732,共9页Journal of Chengdu University of Technology: Science & Technology Edition

基　　金：四川省科技厅重点研发项目(2019YFG0460);中国中铁科研项目(2018-重点-49)。

摘　　要：以地质条件复杂,地形、气象气候条件多变的青藏高原东缘梯度带为研究对象,通过野外大气CO 2实测和岩溶发育情况调查,结合研究区地质特征以及岩矿测试数据,分析了研究区岩溶发育的控制因素——大气CO 2的分布规律。结果发现:对比分析大气CO 2、碳酸盐岩矿组分和区域植被覆盖度,大气CO 2浓度低且受高程控制是影响区域岩溶发育类型和规模的主要因素;研究区岩溶发育类型和规模显示明显的垂向分带性;对比高寒冰雪覆盖条件下冰川岩溶水系统和湿润亚热带岩溶水系统的岩溶水HCO-3含量,研究区HCO-3质量浓度均值为185.00 mg/L,低于桂林和普定等湿润亚热带型岩溶水HCO-3质量浓度均值239.76 mg/L,高于高寒冰雪覆盖型岩溶水HCO-3质量浓度均值131.00 mg/L,显示其独特的高原型岩溶水系统特征;区域夏季植被覆盖度中度以上仅达36%且随流域水系分布,沿河谷两侧高程增加覆盖度减小,显示与高程控制的气温和大气CO 2含量的变化存在高度的一致性。在全球变暖的背景下,青藏高原区气温和大气CO 2的升高,会是青藏高原区溶蚀过程和现代岩溶发育演化的重要驱动因素。Taking the gradient belt at the eastern margin of the Qinghai-Tibet Plateau,which has complicated geological conditions and varied topography and meteorological and climatic conditions,as the research object,combined with geological characteristics of the research area and rock and ore test data,the distribution law of atmospheric CO 2,the controlling factor of karst development in the research area are analyzed through field atmospheric CO 2 measurement and karst development investigation.Comparison of atmospheric CO 2,carbonate mineral composition and regional vegetation coverage in the study area indicates that low atmospheric CO 2 concentration and elevation control are the main factors affecting the type and scale of regional karst development,and the type and scale of karst development in the studied area show obvious vertical zoning.By comparing the[HCO-3]content of karst water in glacial karst water system and humid subtropical karst water system under alpine ice and snow cover,the mean mass concentration of[HCO-3]in the study area is 185.00 mg/L,which was lower than that in the humid subtropical karst water in Guilin and Puding(239.76 mg/L),higher than the mean[HCO-3]mass concentration of alpine snow-covered karst water(131.00 mg/L),displaying its unique characteristics of plateau karst water system.In summer,the vegetation coverage of the region is only 36%above the moderate level,and it decreased with the increase of elevation along both sides of the valley along with the distribution of drainage system,indicating a high consistency with the change of temperature and elevation-controlled atmospheric CO 2 content.It is considered that,under the background of global warming,the increase of air temperature and atmospheric CO 2 in the Qinghai-Tibet Plateau will be an important driving factor for the dissolution process and the development and evolution of modern karst in the Qinghai-Tibet Plateau.

关 键 词：青藏高原 东缘梯度带 大气CO 2 岩溶 

分 类 号：P642.25[天文地球—工程地质学]