第28卷第4期 2014年8月
现代地质 GEOSCIENCE
Vol. 28No. 4
Aug.2014
三峡库区消落带土壤磁性变化规律及成因探讨
朱宏伟'，贺秀斌23，胡云华4，孟庆奎'，朱卫平1
（1.中国国土资源航空物探遥感中心，北京100083；2.中国科学院水利部成都山地灾害与环境研究所，四川成都610041； 3.中国科学院山地表生过程与生态调控重点实验室，四川成都610041；4.四川省第三测绘工程院，四川成都610500）
摘要：为动态跟踪三峡库区消落带土壤物性在水位上涨后所受影响，选择重庆市忠县石宝寨镇长江左岸一带作为研究区，以消落带外同类型土壤作对照，从分析不同水位土壤的磁学性质人手，探究三峡库区蓄水前后土壤性质对环境变化的响应。库区蓄水后，不仅导致了消落带内土壤理化性质变化，还使土壤磁性空间分布在不同水位这一维度上发生显著改变。消落带监测断面数据显示，土壤磁性由蓄水前垂直方向上较稳定的分布，变为目前整体上随淹没水深增加而增高的特征；169~175m高程附近，土壤磁性接近当地同类土壤背景值，而低于此高度尤其是低于157m后，磁化率值迅速增高。磁性的变化是库区蓄水后土壤磁性矿物组成发生改变造成的，由热磁曲线可知，次生磁铁矿的加入是首要原因。扫描电镜下观测出的浑圆状磁铁矿的最可能来源是上游燃烧化石燃料排放的磁性外来污染物，其随江水输
运至此并沉积吸附在土壤颗粒上。研究结果为间接监测污染物的迁移提供了依据。关键词：三峡库区；消落带土壤；水位；磁学性质；磁铁矿
中图分类号：P631
文献标志码：A
文章编号：10008527(2014)04085908
Discussion of Characteristics andOriginof SoilMagnetism Changes in
theThree-gorgeReservoirRiparianZone
ZHU Hong-wei', HE Xiu-bin23, HU Yun-hua', MENG Qing-kui', ZHU Wei-ping(1. China Aero Geophysical Surey and Remote Sensing Center for Land and Resources, Bejing 100083, China : 2. Institute of Mountain Hazards and Enaironment, Chinese Academy of Sciences and Ministry of Water Conserrancy Chengdu, Sichuan 610041, China; 3. Key Laboratory of Mountain Surface Processes and Ecological Regulation,
Chinese Academy of Sciences and Ministry of Water Conserancy, Chengdu, Sichuan 610041, China 4. The Third Sureying and Mapping Engineering Institute of Sichuan, Chengdu, Sichuan 610500, China)
Abstract : In order to dynamically track the property change of soils in the riparian zone of the Three-gorge Res ervoir, taking the left bank of Yangtze River at Shibaozhai Town, Zhong County, Chongqing as an example, the magnetic properties of soils in the riparian zone at different water levels were studied and compared with same type soils outside the riparian zone, furthermore the responses of physical property of soils before and after wate storage to the environment change were analyzed. Based on the analysis of all major monitoring-section data in the riparian zone, the results reveal that after water storage not only the physical and chemical properties of soils in the riparian zone changed, but also the magnetic spatial distribution in different water level was significantly distinct; before water storage the vertical distribution of magnetic susceptibility of soils in the riparian zone was relatively stable, but after water storage the magnetic susceptibility of soils increased with submerged-depth in creasing; in depth of 169 -175 m, the magnetic susceptibility of soils was same to the background value, but it increased rapidly below this depth range, especially below 157 m. This change is resulted from the difference of
收稿日期：2013-12-03；改回日期：2014-02-19；责任编辑：潘令枝。
（06680国（6000009
《科技导报》博士生创新研究资助计划（kjdb201001-8）。
作者简介：朱宏伟，男，博士，工程师，1984年出生，自然地理学专业，主要从事矿物及土壤磁学性质研究。
Email：hw_z007@163.com。