• 责任者：Ouyang Tingping (Key Laboratory of Marginal Sea Geology ; Guangzhou Institute of Geochemistry ; Chinese Academy of Sciences ; Guangzhou 510640 ; China) ; Wan Hongfu
• 刊名：Quaternary Sciences
• 出版年：2012
• 卷期：32(6)
• 关键词：土壤污染 ; soil pollution ; 珠江三角洲 ; Zhujiang River Delta
• 页码：p.1199-1206
• 图表：3 illus., 3 tables, 48 refs.
• 分类号：1800
• issnNo：ISSN1001-7410
• isbnNo：CN11-2708/P

Magnetic susceptibility is one of the most basic and easy to be obtained magnetic parameters.A large number of research indicated that it can be used as a proxy for the monitoring of soil heavy metal pollution.Three hundred agricultural soil samples,including 123 samples polluted by heavy metal and 177 samples without heavy metal pollution,were selected from the Pearl River Delta (PRD), and even in the world since late 1970s.Both low (976Hz) and high (15 616Hz) frequency susceptibility (χlf and χhf respectively) were determined using a Kappabridge MFK1-FA triple frequency susceptibility meter (AGICO). Frequency-dependence magnetic susceptibility (χfd) was calculated from the expression χfd (%)=[(χlf-χhf)/χlf]×100. The results showed that MS of these 300 samples ranged from 1.29×10^-8 to 185.89×10^-8m³/kg,and the average value was 31.20×10^-8m³/kg. Overlay analysis for contour map of MS and administrative map of the PRD indicated that significant spatial distributed difference of agricultural soil MS existed within the PRD.MS of agricultural soil was higher at southern area but lower at northern area,and higher within central area but lower within the eastern and western areas. Four regions with obvious high magnetic susceptibility values were distributed at Zhuhai,Shenzhen,Huiyang and Shunde.Considering many factors including natural and anthropogenic activities,factor analysis was performed using statistical software SPSS 13.0.The results indicated that MS of agricultural soil was mainly controlled by irrigation method,land-use type,mother rock type,and soil type.Difference of these factors should be paid much attention during large spatial scale monitoring.Meanwhile,average MS value of heavy metal polluted samples was much higher than that of non-polluted samples,possibly indicating that MS of agricultural soil was enhanced obviously by heavy metal pollution.Though the mechanism of magnetic enhancement for heavy metal polluted agricultural soil retains unclear,soil magnetic susceptibility can indicate heavy metal pollution degree for agricultural soil.