烟圈反演和视纵向电导解释方法对比

Comparison between the smoke loop inversion and apparent longitudinal conductivity interpretation method

基于浮动薄板理论,研究瞬变电磁场层状介质中视纵向电导的计算方法,利用遗传算法代替常用的阻尼最小二乘法来获取关键参数m。进行"烟圈"反演计算,并分别采用3层H(K)型和4层HK型地电模型对比视纵向电导曲线和电阻率—深度曲线。结果表明,"烟圈"反演具有不需初始模型、计算简便等优点,在定性反演方面,视纵向电导解释方法可以更准确地划分电性层,且能够比较直观地体现电性变化趋势。

The calculation method of apparent longitudinal conductivity in layered media is discussed in this paperbased on transient electromagnetic theory of the floating thin sheet. Genetic algorithm is used instead of dampedleast square method to get the key parameter m . The smoke loop inversion is also calculated, so that the curves ofapparent longitudinal conductivity can be compared with the resistivity-depth curves in the typical geoelectricmodel of 3 layers H, K type and 4 layers HK type. The results show that although the smoke loop inversion is easyto realize and needn’t to set initial model in qualitative inversion area, the interpretation of apparent longitudinalconductivity can distinguish electrical layers more precisely, and it can also indicate the change trend of theelectrical property directly.