基于一维地下水渗透方程详细推导其有限差分解算过程,引入不同于显式差分的隐式差分和中心差分格式,对比分析不同差分格式对地下水模拟结果及其相应地下水重力效应的影响,并对其中的层间参数取值和非线性方程的线性化问题进行探讨.结果表明,在日本Isawa扇形地区超导台站,不同层间参数加权公式能够引起最大约0.15μGal的重力效应差异,影响在1.9%以内;不同差分格式和线性化方法组合形式能够引起最大约0.12 μGal的重力效应差异,影响在1.5%以内.
Using finite difference methods,we deduce the solving algorithms for the one-dimensional groundwater diffusion equation.Then,we compare the influence of different differential schemes on groundwater simulation and the corresponding hydrological effects on gravity.The issues of determining the inter block parameters and linearizing the nonlinear equations are discussed.The results show that,for the superconducting gravimeter (SG) station at Isawa Fan,the influence of different weighting methods of determining inter-block parameters on modeling of groundwater hydrological effects on gravity can reach up to 0.15 μGal,within 1.9% of the total groundwater hydrological effect on gravity,while the influence of different differential schemes and linearizing methods can reach up to 0.12 μGal,within 1.9% of the total groundwater hydrological effect on gravity.