点电源下复杂角域地形影响及校正

Terrain Effect of Complicated Angle-Damain and Topographic Correction for a Point Electric Source

角域是描绘起伏地形的基本单元,通过角域叠加可以获得复杂纯地形产生的视电阻率异常,进而可以进行地形校正。将简单角域视电阻率畸变进行组合叠加得到复杂角域地形的视电阻率畸变,分析了组合叠加误差,并与ANSYS软件数值模拟结果进行了对比。结果表明,在地形起伏不大的情况下,可以通过组合叠加获得复杂角域地形的视电阻率异常。最后给出了利用组合叠加法获得纯地形影响后应用比较法进行地形改正的模型算例;与水平地形时的结果对比表明,比较法可以削弱地形影响,突出局部地质体的异常。

Angle-domain is the basic unit to describe rugged terrain.Apparent resistivity anomaly of complicated terrain can be drawn using the method of angle domain overlapping and then the topographic correction can be performed.We superpose the distorted apparent resistivity of the simple angle-domain terrain to get the distorted apparent resistivity of complicated angle-domain terrain.The method analyses the error of combination and superposition.It＇s also compared with the result of ANSYS modeling.It＇s proved that the apparent resistivity anomaly of complicated angle-domain terrain can be gained by combination and superposition when the terrain does not vary greatly.And finally we show some examples in which the topographic effect is obtained by the method of angle domain overlapping,and the topographic correction is conducted in terms of the terrain correction formulation.The comparison with the result of horizontal terrain shows that the comparison method can weaken the topographic influence,and extrude the anomaly of the local geological body.