Soil water retention characteristics are the key information required in hydrological modeling. Frac-tal models provide a practical alternative for indirectly estimating soil water retention characteristics frompartic...Soil water retention characteristics are the key information required in hydrological modeling. Frac-tal models provide a practical alternative for indirectly estimating soil water retention characteristics fromparticle-size distribution data. Predictive capabilities of three fractal models, i.e, Tyler-Wheatcraft model,Rieu-Sposito model, and Brooks-Corey model, were fully evaluated in this work using experimental datafrom an international database and literature. Particle-size distribution data were firstly interpolated into20 classes using a van Genuchten-type equation. Fractal dimensions of the tortuous pore wall and the poresurface were then calculated from the detailed particle-size distribution and incorporated as a parameter infractal water retention models. Comparisons between measured and model-estimated water retention cha-racteristics indicated that these three models were applicable to relatively different soil textures and pressurehead ranges. Tyler-Wheatcraft and Brooks-Corey models led to reasonable agreements for both coarse- andmedium-textured soils, while the latter showed applicability to a broader texture range. In contrast, Rieu-Sposito model was more suitable for fine-textured soils. Fractal models produced a better estimation of watercontents at low pressure heads than at high pressure heads.展开更多
The fidelity scheme of physical conservation laws has been applied in the dynamic framework of a global spectral model. In this study, a set of diabatic physical processes are also involved. Based on six 30-day numeri...The fidelity scheme of physical conservation laws has been applied in the dynamic framework of a global spectral model. In this study, a set of diabatic physical processes are also involved. Based on six 30-day numerical integrations of real-time data, we show that the full model is able to reproduce the primary features of global energy cycle and hydrological distribution. Additionally, the root-mean-square error is dramatically decreased when diabatic processes are considered. Another advantage is that the false structure of ＂double Intertropical Convergence Zone （ITCZ）＂ is not seen in the result, although the orecioitation rate becomes lower.展开更多
Mineralisation is the result of the coupled multi-geodynamic processes in the crust. The coupled mechano-thermo-hydrological （MTH） processes are the basic physical processes that govern the location of the hydrother...Mineralisation is the result of the coupled multi-geodynamic processes in the crust. The coupled mechano-thermo-hydrological （MTH） processes are the basic physical processes that govern the location of the hydrothermal mineralization, which can be simulated in the computer by using of the numerical codes, such as FLAC. The numerical modeling results can be used not only to explain the features of existing ore deposits, but also to predict the fhvorable mineralization locations. This paper has summarized the basic equations describing coupled MHT processes in the water-saturated porous rocks, the principles of FLAC, and its application to the MHT processes related to copper mineralization in the Fenghuangshan ore field. We used the FLAC to simulate the syn-deformation cooling and fluid flowing evolution after the intrusion was emplaced and solidified. The modeling results suggest a most prospective exploration area where the subsequent exploration supported the prediction and the test bore hole disclosed the high quality copper ore bodies in the target, demonstrating a positive role of the numerical MTH modeling in facilitating predictive ore discovery.展开更多
The monumental Studies to Fathom Principles(Qiongli xue窮理學;1683)by Ferdinand Verbiest S.J.(Nan Huairen南懷仁,1623–1688)was never printed,and its exact content is not known.A section of the only extant,though incom...The monumental Studies to Fathom Principles(Qiongli xue窮理學;1683)by Ferdinand Verbiest S.J.(Nan Huairen南懷仁,1623–1688)was never printed,and its exact content is not known.A section of the only extant,though incomplete,manuscript deals with fluvial flood prevention and river control measures,a subject that until then had not cropped up in any Chinese-language work of the Jesuits.In this section,Verbiest not only described the already well-known Aristotelian theory of the origin of rivers,but also introduced to China new scientific propositions,concepts,and numerical examples originating from the seminal Renaissance work Della misura dell’acque correnti(Of the Mensuration of Running Waters;1628)by Benedetto Castelli(1578–1643).In addition,Verbiest presented to his readers some noteworthy examples of pertinent Western achievements such as the pound-lock with miter gate,and he provided them with a simple economic analysis of flood control options.The significance and possible influence of Verbiest’s text on further developments in Chinese approaches to water engineering are discussed,highlighting a hitherto largely disregarded facet of Western science and technology transfer in the field of river hydraulics and flood management.展开更多
Based on the basic principles of hydrogeology and soil mechanics, studied thegenesis mechanism and control factors of settling of ground surface caused by the drainageof the aquifer in the construction of coal mines, ...Based on the basic principles of hydrogeology and soil mechanics, studied thegenesis mechanism and control factors of settling of ground surface caused by the drainageof the aquifer in the construction of coal mines, and put forward a corresponding calculatingmodel demonstrated by practical example.The study provides mining areas,which are covered with a very thick Quaternary soil layer and abundant ground water, witha theoretical basis aimed at forecasting the settling of ground surface.展开更多
To support navigational and environmental applications in coastal waters, marine opera- tional forecast models must be developed and implemented. A forecast model must guarantee that it is scientifically sound and pra...To support navigational and environmental applications in coastal waters, marine opera- tional forecast models must be developed and implemented. A forecast model must guarantee that it is scientifically sound and practically robust for performance and must meet or excel all target frequencies or durations before being released to the public. This paper discusses the standard policies and procedures for evaluation of operational marine forecast models. The primary variables to be evaluated are water lev- els, currents and water density (water temperature and salinity).展开更多
基金Project supported by the National Natural Science Foundation of China (No, 49971041), the National Key Basic Research Support Foundation (NKBRSF) of China (No. G1999011803) the Director Foundation of the Institute of Soil Science, CAS (No. ISSDF0004).
文摘Soil water retention characteristics are the key information required in hydrological modeling. Frac-tal models provide a practical alternative for indirectly estimating soil water retention characteristics fromparticle-size distribution data. Predictive capabilities of three fractal models, i.e, Tyler-Wheatcraft model,Rieu-Sposito model, and Brooks-Corey model, were fully evaluated in this work using experimental datafrom an international database and literature. Particle-size distribution data were firstly interpolated into20 classes using a van Genuchten-type equation. Fractal dimensions of the tortuous pore wall and the poresurface were then calculated from the detailed particle-size distribution and incorporated as a parameter infractal water retention models. Comparisons between measured and model-estimated water retention cha-racteristics indicated that these three models were applicable to relatively different soil textures and pressurehead ranges. Tyler-Wheatcraft and Brooks-Corey models led to reasonable agreements for both coarse- andmedium-textured soils, while the latter showed applicability to a broader texture range. In contrast, Rieu-Sposito model was more suitable for fine-textured soils. Fractal models produced a better estimation of watercontents at low pressure heads than at high pressure heads.
基金supported by the National Natural Science Foundation of China under Grant Nos. 40775067 and 40475026
文摘The fidelity scheme of physical conservation laws has been applied in the dynamic framework of a global spectral model. In this study, a set of diabatic physical processes are also involved. Based on six 30-day numerical integrations of real-time data, we show that the full model is able to reproduce the primary features of global energy cycle and hydrological distribution. Additionally, the root-mean-square error is dramatically decreased when diabatic processes are considered. Another advantage is that the false structure of ＂double Intertropical Convergence Zone （ITCZ）＂ is not seen in the result, although the orecioitation rate becomes lower.
文摘Mineralisation is the result of the coupled multi-geodynamic processes in the crust. The coupled mechano-thermo-hydrological （MTH） processes are the basic physical processes that govern the location of the hydrothermal mineralization, which can be simulated in the computer by using of the numerical codes, such as FLAC. The numerical modeling results can be used not only to explain the features of existing ore deposits, but also to predict the fhvorable mineralization locations. This paper has summarized the basic equations describing coupled MHT processes in the water-saturated porous rocks, the principles of FLAC, and its application to the MHT processes related to copper mineralization in the Fenghuangshan ore field. We used the FLAC to simulate the syn-deformation cooling and fluid flowing evolution after the intrusion was emplaced and solidified. The modeling results suggest a most prospective exploration area where the subsequent exploration supported the prediction and the test bore hole disclosed the high quality copper ore bodies in the target, demonstrating a positive role of the numerical MTH modeling in facilitating predictive ore discovery.
基金funded by the German Research Foundation(DFG)for the years 2018 to 2022
文摘The monumental Studies to Fathom Principles(Qiongli xue窮理學;1683)by Ferdinand Verbiest S.J.(Nan Huairen南懷仁,1623–1688)was never printed,and its exact content is not known.A section of the only extant,though incomplete,manuscript deals with fluvial flood prevention and river control measures,a subject that until then had not cropped up in any Chinese-language work of the Jesuits.In this section,Verbiest not only described the already well-known Aristotelian theory of the origin of rivers,but also introduced to China new scientific propositions,concepts,and numerical examples originating from the seminal Renaissance work Della misura dell’acque correnti(Of the Mensuration of Running Waters;1628)by Benedetto Castelli(1578–1643).In addition,Verbiest presented to his readers some noteworthy examples of pertinent Western achievements such as the pound-lock with miter gate,and he provided them with a simple economic analysis of flood control options.The significance and possible influence of Verbiest’s text on further developments in Chinese approaches to water engineering are discussed,highlighting a hitherto largely disregarded facet of Western science and technology transfer in the field of river hydraulics and flood management.
文摘Based on the basic principles of hydrogeology and soil mechanics, studied thegenesis mechanism and control factors of settling of ground surface caused by the drainageof the aquifer in the construction of coal mines, and put forward a corresponding calculatingmodel demonstrated by practical example.The study provides mining areas,which are covered with a very thick Quaternary soil layer and abundant ground water, witha theoretical basis aimed at forecasting the settling of ground surface.
基金Supported by the National Natural Science Foundation of China (No. 40376010).
文摘To support navigational and environmental applications in coastal waters, marine opera- tional forecast models must be developed and implemented. A forecast model must guarantee that it is scientifically sound and practically robust for performance and must meet or excel all target frequencies or durations before being released to the public. This paper discusses the standard policies and procedures for evaluation of operational marine forecast models. The primary variables to be evaluated are water lev- els, currents and water density (water temperature and salinity).
