土壤学报2017，Vol.54Issue(5)：1303-1312,10.DOI:10.11766/trxb201703270059
利用纳米磁性材料表征地表溅蚀特征的初探
Feasibility Study of Using Nano Magnetic Materials to Characterize Splash Erosion of Land Surface
摘要
Abstract
Certain achievements have been made in the study on soil erosion on slopes using magnetic tracers. However,the traditional magnetic tracer method is far from effective enough to meet the requirements of the study to characterize splash erosion caused by each rainfall event. Therefore,an in-lab splash erosion simulation experiment was carried out over on a bed of non-magnetic quartz sand mixed separately with nano magnetic materials,different in particle size(20 nm or 200 nm),at a rate of 1.5%,2.5% and 3.5% in this study,Magnetic susceptibility meter and Three-dimensional Laser Micro-topographical Scanner was used to monitor variation of the magnetism of the land surface and its relationship with changes in topographic characteristics of the land surface subjected to splash erosion,and hence to study feasibility of using nano magnetic materials to characterize splash erosion. Results show that the 20 nm magnetic material was more effective than the 200 nm magnetic material in raising magnetism of the quartz sand over its background value,and the effect varied sharply with concentration or incorporation rate of the magnetic materials;and the higher the concentration of the material,the more durable the tracing effect. After splash erosion,surface magnetic susceptibility declined gradually with the time going on,displaying a high logarithmic function relation expressed as χ1= aln(t)+b;The use of 20nm magnetic material,3.5% in concentration effectively characterized changes in splash erosion rate of the quartz sand(p<0.01)with a power function relation expressed as χ2=aMb(χ2 = sediment susceptibility and M = splash erosion amount). The highly significant relationship between the variation of magnetic susceptibility of the 20 nm magnetic materials in the 3 minutes of splash erosion and the variation of microrelief demonstrates that the 20nm magnetic material can be used to characterize erosion degree,up to the range of -5~10 mm,of the land surface subjected to splash erosion within a short period of time. All the findings in this study prove that it is,to a certain extent,feasible to use 20 nm magnetic material to characterize splash erosion of land surface. Moreover,this study may help open up some new ideas and develop new methods for further study on utilization of the magnetic tracing method.关键词
溅蚀/磁性示踪剂/纳米磁性材料/磁化率/微地形Key words
Splash erosion/Magnetic tracer/Nano magnetic materials/Magnetic susceptibility/Micro-topography分类
生物科学引用本文复制引用
汪倩,林金石,黄炎和,蒋芳市,周曼,林蕾,朱璨..利用纳米磁性材料表征地表溅蚀特征的初探[J].土壤学报,2017,54(5):1303-1312,10.基金项目
国家科技支撑计划项目(2014BAD15B0303)、国家自然科学基金项目(41571272)、福建省自然科学基金项目(2015J01156)资助 Supported by the National Key Technology R&D Program of China(No. 2014BAD15B0303),the National Natural Science Foundation of China(No. 41571272),the Natural Science Foundation of Fujian Province,China(No. 2015J01156) （2014BAD15B0303）
