中尺度模拟土壤油污染区探地雷达探测效果分析  

Effect analysis of mesoscale simulation to detect soil oil pollution areas with ground penetrating radar

作　　者：刘倩 郭秀军[1,2,3] 邵帅 高畅[1] LIU Qian;GUO Xiu-jun;SHAO Shuai;GAO Chang(College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China;Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Qingdao 266100,China;Key Laboratory of Marine Environmental Science and Ecology,Ministry of Education,Qingdao 266100,China)

机构地区：[1]中国海洋大学环境科学与工程学院,青岛266100 [2]山东省海洋环境地质工程重点实验室,青岛266100 [3]海洋环境与生态教育部重点实验室,青岛266100

出　　处：《地球物理学进展》2020年第1期322-330,共9页Progress in Geophysics

基　　金：国家自然科学基金(41772307)资助.

摘　　要：为使物理模拟实验效果与实际探测情形更为接近,在室外自然条件下建立中尺度土壤石油污染实验模型,油污染区扩展深度超过1 m,采用实地探测中常用的500 MHz雷达天线进行长期定时探测.通过实测雷达图像特征、土壤含水量含油量分析,并对比前人开展的小尺度室内模拟试验结果,综合评价探地雷达对油污染区的探测效果.研究表明探地雷达探测图像异常特征与污染区扩散阶段密切相关:包气带内油污染区会引起振幅增强;毛细带的油污染区则表现为水位面反射轴附近清晰可辨的高幅异常区,且水位面反射轴呈下凹状;随扩散过程持续进行,异常区下移与水位面反射轴相交,并产生水平扩张.当污染土含油饱和度大于20%时,可通过雷达图像异常区圈定污染范围;当污染土含油饱和度大于15%时,可通过频谱图出现低频响应的位置圈定污染区水平范围.中尺度实验结果与室内小尺度模拟结果具有一致性,可作为油污染区雷达图像异常的解译依据.In order to make the effect of the physical simulation experiment closer to the actual detection situation,an experimental model for mesoscale soil petroleum pollution was established under outdoor natural conditions to extend the depth of the oil contamination area by more than 1 m,and the long-term timing was implemented using a 500 MHz radar antenna commonly used in field detection.Through the measurement of radar image characteristics,soil-water content and oil content,and compared with the results of previous small-scale indoor simulation experiments carried out,a comprehensive evaluation of the detection effect of the Ground Penetrating Radar(GPR)on oil pollution areas was made.Studies have shown that the anomalous characteristics of GPR detection images are closely related to the diffusion phase of the contaminated area:the oilcontaminated zone in the unsaturated zone will cause an increase in the amplitude;the oil-contaminated zone near the water level surface will be clearly visible near the reflection axis of the water level,high amplitude anomalies will appear,and the reflection axis of the water level surface is concave;as the diffusion process continues,the anomalous area moves down and intersects with the reflection axis of the water level surface,and lateral expansion occurs.When the oil saturation is greater than 20%,the radar image anomaly zone can be used to delineate the contaminated area;when the oil saturation is greater than 15%,the frequency level of the spectrum diagram can be used to delineate the pollution range.The results of mesoscale experiments are consistent with the results of small-scale indoor simulations and can be used as the basis for the abnormal interpretation of oil-contaminated areas.

关 键 词：探地雷达 中尺度模拟 油污染区探测 异常特征 信号分析 

分 类 号：P631[天文地球—地质矿产勘探]