The regularization contributes to the resolution and stability in geophysical inversion. The authors apply dual-parameter shaping regularization to full waveform inversion, aiming at two points ： （ 1 ） improving th...The regularization contributes to the resolution and stability in geophysical inversion. The authors apply dual-parameter shaping regularization to full waveform inversion, aiming at two points ： （ 1 ） improving the boundary resolution, and （2） increasing convergence. Firstly, the forward modeling is done, and the inversion is processed with the optimal solution. Compared with classical Tikhonov regularization scheme, the method re fleets better resolution and stronger convergence. Then, Marmousi model is experimented and inversed, and the deep structure has a sharper outline. The phase residual comparison illustrates weaker cycle-slipping. And a choice scheme of parameter is applied in FWI.展开更多
To simulate the soil moisture variation in cropland, a two-parameter exponential recession model was derived to depict the recession process of soil moisture in the root zone. The model is based on the assumption that...To simulate the soil moisture variation in cropland, a two-parameter exponential recession model was derived to depict the recession process of soil moisture in the root zone. The model is based on the assumption that the recession rate of soil water is proportional to the potential evapotranspiration rate and the difference of soil water content and steady soil water content. Two parameters in this model are soil texture-dependent recession constant and steady soil water content. The model was calibrated and validated with measured soil water data at two experiment sites in North China with different soil textures and cropping systems. Coefficients of determination between measured and model simulated soil water content were all greater than 0.7, indicating that both models gave satisfactory simulation results. Results showed that values of two parameters mentioned above are both larger for finer soil than those for coarser soil. At the same potential evapotranspiration rate and soil water content, the recession rate of finer soil is usually lower than that of coarser soil. The proposed model can be used in irrigation management to predict approximate date for irrigation, as well as be embedded into watershed hydrological models to estimate the antecedent precipitation index.展开更多
文摘The regularization contributes to the resolution and stability in geophysical inversion. The authors apply dual-parameter shaping regularization to full waveform inversion, aiming at two points ： （ 1 ） improving the boundary resolution, and （2） increasing convergence. Firstly, the forward modeling is done, and the inversion is processed with the optimal solution. Compared with classical Tikhonov regularization scheme, the method re fleets better resolution and stronger convergence. Then, Marmousi model is experimented and inversed, and the deep structure has a sharper outline. The phase residual comparison illustrates weaker cycle-slipping. And a choice scheme of parameter is applied in FWI.
基金Under the auspices of National Natural Science Foundation of China(No.51279077,91125017)
文摘To simulate the soil moisture variation in cropland, a two-parameter exponential recession model was derived to depict the recession process of soil moisture in the root zone. The model is based on the assumption that the recession rate of soil water is proportional to the potential evapotranspiration rate and the difference of soil water content and steady soil water content. Two parameters in this model are soil texture-dependent recession constant and steady soil water content. The model was calibrated and validated with measured soil water data at two experiment sites in North China with different soil textures and cropping systems. Coefficients of determination between measured and model simulated soil water content were all greater than 0.7, indicating that both models gave satisfactory simulation results. Results showed that values of two parameters mentioned above are both larger for finer soil than those for coarser soil. At the same potential evapotranspiration rate and soil water content, the recession rate of finer soil is usually lower than that of coarser soil. The proposed model can be used in irrigation management to predict approximate date for irrigation, as well as be embedded into watershed hydrological models to estimate the antecedent precipitation index.
