丹江口库区小流域土壤磁化率变异特征及影响因素研究  

Spatial Variation of Soil Magnetic Susceptibility and Its Influencing Factors in a Small Watershed of the Danjiangkou Reservoir Area

作　　者：刘洋 梅嘉洺 李仪 唐亚男 贺美 姜庆虎[1] 刘峰[1] LIU Yang;MEI Jiaming;LI Yi;TANG Yanan;HE Mei;JIANG Qinghu;LIU Feng(Key Laboratory of Aquatic Botany and Watershed Ecology,Wuhan Botanical Garden,Chinese Academy of Sciences,Wuhan 430074,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Science,Tibet University,Lhasa 850012,China)

机构地区：[1]中国科学院武汉植物园水生植物与流域生态重点实验室,武汉430074 [2]中国科学院大学,北京100049 [3]西藏大学理学院,拉萨850012

出　　处：《地球与环境》2020年第1期96-104,共9页Earth and Environment

基　　金：国家自然科学基金项目(31600377、31470526);科技基础性工作专项“南水北调(中线)水源地生物群落环境调查”(2015FY110400)。

摘　　要：土壤磁化率是表征土壤侵蚀特征的重要指标。本文以丹江口库区五龙池流域土壤为研究对象,沿坡位选取18个条带共采集85个表层(0~10 cm)土壤样品,通过对不同土地利用类型及景观位置的土壤磁化率分析以及与粒度关联分析,揭示小流域土壤磁化率变异特征并评估其影响因素。结果表明:1)土壤质量磁化率、频率磁化率平均含量分别为34.4×10^-8m^3/kg、9.69%,二者均呈中等的空间自相关,其值分别为0.59、0.51;2)不同土地利用类型中,土壤磁化率差异显著,其中质量磁化率为坡耕地>梯田>灌木林地>用材林地;频率磁化率为坡耕地>梯田>用材林地>灌木林地;不同景观位置上,土壤磁化率坡顶最低,中部最高,坡底居中;3)土壤磁化率与黏粒、粉粒含量存在显著正相关关系,与砂粒含量呈显著负相关关系。研究结果为间接监测流域土壤迁移与环境演变过程提供了依据,增加对流域内生源元素伴随土壤侵蚀迁移的演变历史和过程的理解,对于保护库区水环境和生态安全有重要意义。Magnetic susceptibility is an important index to characterize the process of soil erosion.A total of 85 topsoil samples(0-10 cm)were collected from 18 belts along slopes in the Wulongchi watershed,the Danjiangkou reservoir area.Soil magnetic susceptibilities of collected samples were characterized and the spatial distribution of soil magnetic susceptibilities and its influential factors,i.e.land use types,landscape locations and particle size,were analyzed by correlation analysis,geostatistical analysis and GIS technology.The results showed that:(1)the averages of soil mass susceptibilities(χlf)and frequency dependent susceptibilities(χfd)were 34.4×10-8m3/kg and 9.69%,respectively,both of which showed the moderate spatial autocorrelation with values of 0.59 and 0.51,respectively;(2)the soil magnetic susceptibilities were significantly different among different land use types,the order ofχlfwas sloping farmland>terrace>shrub>timber woodland,the order ofχfdwas sloping farmland>terrace>timber woodland>shrub,and theχlf value was location sensitive with the lowest and the highest values occurring at the top and the middle of the slope,respectively;(3)theχlfshowed a strong positive correlation with the content of clay and silt in soil,and a strong negative correlation with the content of sand in soil.The findings of this study provide an important scientific basis for the strategy of indirect monitoring of the watershed soil particle movement and the environment evolution,which improves the understanding of processes of nutrients along with the soil erosion history in watersheds,such is of great significance for the regional water environment and ecological security.

关 键 词：土壤磁化率 空间变异 影响因素 丹江口库区 

分 类 号：S153.2[农业科学—土壤学]