起伏地表弹性波数值模拟的不等距差分法:以黄土塬区为例

Non-equidistant difference method for elastic wave numerical simulation with irregular surface:a case study of loess tableland region

针对包含复杂近地表及起伏地形的黄土塬区的正演模拟问题,提出一种弹性波不等距差分数值模拟方法。该方法不需要在地表处进行阶梯状离散,且在计算中可以将自由地表边界条件融入不等距差分格式中,能够提高计算效率。采用一个倾斜模型进行模拟,经与特征变量法对比,得到相同的波场,验证了该方法的有效性。对实际复杂黄土塬区模型进行试算,得到其波场快照与地震记录,证明了在复杂黄土塬区的适用性和可能的应用前景。

In order to solve the seismic forward modeling of loess tableland region with complex near-surface and irregular surface,the non-equidistant difference method for elastic wave numerical simulation is proposed.This method does not need to perform staircase-shaped discretization at the surface,and the free surface boundary condition can be integrated into the non-equidistant difference scheme to improve the computational efficiency.An inclined model is used for simulation,and we get the same wavefield by comparing it with the characteristic variable method,which shows the effectiveness.The wavefield snapshot and seismograms are obtained by actual model of the complex loess tableland region,which proves the applicability and possible application prospects.