摘要
天然电场选频法在地下水勘探中应用效果较好,但目前对该方法理论研究甚少.主要从理论与实践两方面研究垂直断层上天然电场选频法的异常特征.根据经典的大地电磁测深法理论,从麦克斯韦方程组和边界条件出发,推导谐变大地电磁场中垂直断层上方,地面水平电场的解析计算式;然后对理论模型的各个参数进行假定,计算获得地表主剖面上水平电场强度分量曲线;最后将理论模型上的模拟计算结果与实测曲线进行对比分析.根据对比分析可知,二者曲线形态相似、特征相同,由此推断选频法的异常主要是由天然感应二次电场所致.
The natural electric field frequency selection method has good effects on ground water exploration, but is short of theoretical research. The anomaly of a vertical fault of frequency selection method was studied from theory and practice. According to classical theory of magnetotelluric sounding, firstly, based on the Maxwell equations and the boundary conditions, the analytic expressions of horizontal electric field components on the ground was derived for a vertical fault in a harmonic magnetotelluric field. Secondly, all parameters of the model were supposed, and anomalous curves of horizontal electric field intensity on the ground main profile were obtained. At last, theoretical curves were compared with practical curves. Their curves had similar characteristics, and therefore the anomaly of frequency selection method was caused by natural induced electric field.
出处
《湖南科技大学学报(自然科学版)》
CAS
北大核心
2013年第4期32-37,共6页
Journal of Hunan University of Science And Technology:Natural Science Edition
基金
湖南省自然科学基金项目(12JJ3035)
湖南省科技计划项目(2011SK3195)
关键词
地球物理
选频法
模拟
天然电场
地下水
电磁场
geophysics
frequency selection method
simulation
natural electric field
ground water
electromagnetic field