摘要
为了研究地形对线源频率域电磁测深测量结果的影响,本文介绍了起伏地形下的线源频率域电磁场的二维正演模拟方法.在正演模拟过程中采用有限单元法,首先为了模拟起伏地形,用三角形单元对研究区域进行网格剖分;然后再对每个单元进行线性插值、积分、总体合成;最后通过求解线性方程组得出地表的电磁响应.文章最后给出了山谷与山脊模型的数值模拟结果,通过模拟结果的对比可知:下凹地形对线源频率域电磁测深测量结果的影响小,而上凸地形则对线源频率域电磁测深测量结果的影响较大.
In order to research the effect of terrain on frequency-domain electromagnetic sounding, we present a program to model the frequency-domain electromagnetic response in a 2D terrain area with a line source of current. To solre the forward problem, the finite element method is used. First, in order to model the terrain, the research region is divided into triangles. Second, it performs linear interpolation, integration and general synthesis on every element. Finally, by solving the linear equations, the surface electromagnetic response is obtained. This paper shows the numerical results of hollow and ridge models. Compareing these results, it is known that the effect of convex terrain in the frequency-domain electromagnetic sounding is lager than the effect of concave terrain in frequency-domain electromagnetic sounding.
出处
《地球物理学进展》
CSCD
北大核心
2011年第3期948-953,共6页
Progress in Geophysics
基金
国家科技支撑计划项目(2011BAB04B08)
中南大学自由探索计划(2011QNZT010)联合资助
关键词
频率域电磁法
有限单元法
二维正演
地形
线源
frequency-domain electromagnetic
finite-element method
2D forward modeling
terrain
line source
