Since S-wave velocity of the subsurface is an important parameter in near surface applications,many studies have been conducted for its estimation.Among the various methods that use surface waves or body waves,Rayleig...Since S-wave velocity of the subsurface is an important parameter in near surface applications,many studies have been conducted for its estimation.Among the various methods that use surface waves or body waves,Rayleigh wave inversion is the most popular.In practice,the densities and P-wave velocities of different layers are usually assumed to be known to avoid ill-posed problems,as they have less influence on the dispersion curves.However,improper assignment of these two groups of parameters leads to inaccurate estimation of the S-wave velocity profile.In order to address this problem,the all-parameters Rayleigh wave inversion strategy is proposed in which the S-wave velocities,layer thicknesses,densities and P-wave velocities of different layers are included as the unknown parameters for inversion.Meanwhile,the transitional Markov Chain Monte Carlo(TMCMC)algorithm is applied for the implementation of all-parameters Rayleigh wave inversion.One simulated example and two real-test applications are demonstrated to verify the capability of the proposed method in the estimation of the S-wave velocity profile,the densities and the P-wave velocities.Furthermore,it is verified that the proposed method achieved more accurate S-wave velocity profile estimation than the traditional approach.展开更多
An urban net all-wave radiation parameterization scheme is evaluated using annual datasets for 2010 recorded at a Beijing urban observation site.The statistical relationship between observed data and simulation data o...An urban net all-wave radiation parameterization scheme is evaluated using annual datasets for 2010 recorded at a Beijing urban observation site.The statistical relationship between observed data and simulation data of net radiation has a correlation coefficient of 0.98 and model efficiency of 0.93.Therefore,it can be used to simulate the radiation balance of Beijing.This study analyzes the variation in the radiation balance for different underlying surfaces.To simulate radiation balance differences,we set four pure land-cover types(forest,grass,roads,and buildings).Keeping all other conditions inputted unchanged,we model the radiation balance by changing the land-cover type.The results show that the effects of different underlying surfaces on radiation differ,and that there is much upward long-wave radiation,accounting for 84.3% of the total radiation energy falling incident on the land surface.The annual averages of net radiation for the four land-cover types are in the range of 38.2-53.4 W/m2.The net radiation of the grass surface is minimal while that of the roads surface is maximal.Additionally,with urbanization the net radiation values of common types of land-cover change,such as conversion from forest to roads,grass to roads,and grass to buildings,all have increasing trends,indicating that net radiation usually increases with urban sprawl.展开更多
基金University of Macao(File No.MYRG2018-00048-AAO)the Science and Technology Development Fund,Macao SAR(File No.SKL-IOTSC-2018-2020)。
文摘Since S-wave velocity of the subsurface is an important parameter in near surface applications,many studies have been conducted for its estimation.Among the various methods that use surface waves or body waves,Rayleigh wave inversion is the most popular.In practice,the densities and P-wave velocities of different layers are usually assumed to be known to avoid ill-posed problems,as they have less influence on the dispersion curves.However,improper assignment of these two groups of parameters leads to inaccurate estimation of the S-wave velocity profile.In order to address this problem,the all-parameters Rayleigh wave inversion strategy is proposed in which the S-wave velocities,layer thicknesses,densities and P-wave velocities of different layers are included as the unknown parameters for inversion.Meanwhile,the transitional Markov Chain Monte Carlo(TMCMC)algorithm is applied for the implementation of all-parameters Rayleigh wave inversion.One simulated example and two real-test applications are demonstrated to verify the capability of the proposed method in the estimation of the S-wave velocity profile,the densities and the P-wave velocities.Furthermore,it is verified that the proposed method achieved more accurate S-wave velocity profile estimation than the traditional approach.
基金supported by the National Basic Research Program of China (2010CB950902)the National Natural Science Foundation of China (40971223 and 40901224)the Major Program for the Fundamental Research of the Chinese Academy of Sciences (KZCX2-EW-306)
文摘An urban net all-wave radiation parameterization scheme is evaluated using annual datasets for 2010 recorded at a Beijing urban observation site.The statistical relationship between observed data and simulation data of net radiation has a correlation coefficient of 0.98 and model efficiency of 0.93.Therefore,it can be used to simulate the radiation balance of Beijing.This study analyzes the variation in the radiation balance for different underlying surfaces.To simulate radiation balance differences,we set four pure land-cover types(forest,grass,roads,and buildings).Keeping all other conditions inputted unchanged,we model the radiation balance by changing the land-cover type.The results show that the effects of different underlying surfaces on radiation differ,and that there is much upward long-wave radiation,accounting for 84.3% of the total radiation energy falling incident on the land surface.The annual averages of net radiation for the four land-cover types are in the range of 38.2-53.4 W/m2.The net radiation of the grass surface is minimal while that of the roads surface is maximal.Additionally,with urbanization the net radiation values of common types of land-cover change,such as conversion from forest to roads,grass to roads,and grass to buildings,all have increasing trends,indicating that net radiation usually increases with urban sprawl.
