CAJ | 학술논문

地形对大地电磁场的影响规律研究对于实际大地电磁测深反演解释具有重要的意义。基于矢量有限元法进行了大地电磁三维地形响应数值模拟。首先与二维地形模拟结果比较，验证了算法的正确性；接着，分别对1个山峰地形和1个山谷地形进行了模拟；最后，比较了二维模拟与三维模拟结果。结果表明：三维阻抗张量的 Zxy 模式和 Z yx 模式都会受到地形影响；用二维地形模拟结果去近似三维地形响应，二维 TE 模式与真实三维响应结果差别很大，TM 模式接近真实三维响应结果；如采用二维反演处理带地形的三维 MT 数据，TM 极化模式反演更为合理。
지형대대지전자장적영향규률연구대우실제대지전자측심반연해석구유중요적의의。기우시량유한원법진행료대지전자삼유지형향응수치모의。수선여이유지형모의결과비교，험증료산법적정학성；접착，분별대1개산봉지형화1개산곡지형진행료모의；최후，비교료이유모의여삼유모의결과。결과표명：삼유조항장량적 Zxy 모식화 Z yx 모식도회수도지형영향；용이유지형모의결과거근사삼유지형향응，이유 TE 모식여진실삼유향응결과차별흔대，TM 모식접근진실삼유향응결과；여채용이유반연처리대지형적삼유 MT 수거，TM 겁화모식반연경위합리。
It is of great significance to study the effect of topography to the magnetotelluric inversion and interpretation.A vector finite-element algorithm has been applied to simulate magnetotelluric (MT) effect of 3D topography models.First,the algorithm was verified by comparison with the modeling result of a 2D ridge model.Then, the effect of 3D topography was simulated for a 3D positive trapezoidal-hill model and a negative trapezoidal-hill model respectively.In addition,we also compared the results of 2D and 3D simulation.The results show that Z xy and Z yx are both affected by the terrain, the difference between 2D TE mode and real 3D response is great,whereas the 2D TM mode response is similar to the real 3D response.If we invert the 3D MT data by a 2D program with terrain,the TM polarization mode inversion is more reasonable.