A preliminary study on the offshore stratigraphy in Hong Kong and its hydrogeological implications     

Hiu Tung Kwong  Jiu Jimmy Jiao  Lung Sang Chan 《Environmental Earth Sciences》2016,75(11):975

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Selection of ground motion attenuation model for Peninsular Malaysia due to far-field Sumatra earthquakes     

Tze Che Van  Tze Liang Lau  Chai Fung Mok 《Natural Hazards》2016,80(3):1865-1889

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Analytical studies on transient groundwater flow induced by land reclamation using different fill materials          下载免费PDF全文

Litang Hu  Jiu Jimmy Jiao 《水文研究》2014,28(4):1931-1938

Land reclamation may have a significant influence on groundwater regimes. Analytical solutions have been developed in the past to study the impact of land reclamation on a steady‐state groundwater flow and transient flow in fill materials, assuming that the reclamation site consists of a single zone of uniform hydraulic parameters. In this paper, we derive analytical solutions to describe the transient water table change in response to multi‐stage land reclamation where the fill material is uniform in each stage but the hydraulic conductivity of the fill material varies from stage to stage. By introducing the method of separation of variables, we develop a transient analytical solution to study the impact of land reclamation consisting of fill material with different hydraulic properties on groundwater dynamics. The results show that the water table first increases significantly into the reclaimed zone following the fill material deposition, and then the increase gradually propagates into the original aquifer. The change of water table in the original aquifer mainly depends on the value of hydraulic conductivity of the fill materials. Examples in this paper illustrate how the aquifer system experiences a long time unsteady‐state flow as a result of the reclamation, and it takes at least tens of years for the system to approach a new equilibrium. It is suggested that for a large‐scale reclamation project, the response of the groundwater regime to reclamation should be carefully studied. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Impact of coastal land reclamation on ground water level and the sea water interface   总被引：6，自引：0，他引：6  

Guo H  Jiao JJ 《Ground water》2007,45(3):362-367

Land reclamation in coastal areas may have a significant effect on local ground water systems. Steady-state analytic solutions based on Dupuit and Ghyben-Herzberg assumptions are derived to evaluate this effect. Two situations are considered, both with ground water flow resulting from precipitation recharge: the coastal aquifer of an extensive landmass and an island. The results show that after reclamation, the water table rises and the salt water-fresh water interface moves seaward. The degree of these changes depends on the extent of reclamation and the hydraulic conductivity of the fill material. For the island situation, the reclamation displaces the ground water divide and changes the ground water conditions in the entire island. An unintended advantage of the reclamation is an increase of fresh ground water resource because the reclaimed land can be an additional aquifer and rain recharge takes place over a larger area.  相似文献   

Macrobenthic Community in Tolo Harbour,Hong Kong and its Relations with Heavy Metals     

Kouping Chen  Shengyan Tian  Jiu Jimmy Jiao 《Estuaries and Coasts》2010,33(3):600-608

The present study investigated the macrobenthic community in Tolo Harbour, Hong Kong, aiming at linking heavy metal concentrations to differences in macrobenthic community. The stations investigated in Tolo Harbour have widely contrasting features, with some areas located in the Plove Cove displaying both high species richness and abundance while other areas displaying quite impoverished or even void of macrobenthos. High diversity and abundance of macrobenthos in areas with low heavy metal concentrations were recorded. Strong negative correlation between macrobenthic diversity and heavy metal concentrations was found, and this implicated the pollution-induced degradation of macrobenthos in some locations in Tolo Harbour. These results support the Pearson–Rosenberg model for succession along a pollution gradient.  相似文献   

Comparison of spin-flip and normal synchrotron radiations from a charge rotating in a magnetized plasma     

P. C. W. Fung  W. Y. P. Fung 《Astrophysics and Space Science》1979,66(1):235-254

We have deduced the intensity spectral function for the spin-flip synchrotron radiation in the presence of a plasma. Using parameters appropriate to astrophysical conditions, we have attempted to compare the characteristics of the spin-flip synchrotron radiation and the normal synchrotron radiation in a magnetized plasma arising from an electron or positron rotating around the magnetic field. A rotating charge gives the maximum possible synchrotron radiative power as compared to a charge of the same energy but moving in a helical path. Since the spin-flip radiational does not depend on the form of the orbital path, whether circular or helical or along a straight line, the analysis presented here gives the lower limit of the relative importance of the spin-flip radiation to the normal synchrotron radiation emitted by the same radiator.  相似文献   

New approach of studying electromagnetic mode coupling in inhomogeneous magnetized plasma     

F. T. Cheng  P. C. W. Fung 《Astrophysics and Space Science》1977,49(2):367-388

In this paper we use a new approach to derive the system of first-order coupled equations governing the propagation of electromagnetic waves in an inhomogeneous magnetized plasma for normal incidence. In this new approach we employ a step model and use Maxwell's equations indirectly. The method we present here possesses simplicity in mathematical manipulation and gives a clearer physical picture of the mechanism of mode-coupling. The variablesE _i used in the coupled equations are directly related to experimental measurements. Our result is shown to be equivalent to that obtained by Budden and Clemmow (1957).  相似文献   

Preliminary study on the source field mode of geomagnetic six-month-period variations     

P. F. Chen  P. C. W. Fung 《中国科学D辑(英文版)》1997,40(2):183-188

The monthly means of north component X of geomagnetic field from 16 observatories during 1984–1988 were analyzed using the Sompi spectral analysis technique Most of these observatories are located in China. The analysis of the semiannual variations indicates that the latitude has no apparent effect on the X component. This clearly implies that the source field mode of semiannual variations cannot simply be described by using the p ₁ ⁰ mode. Using the p ₁ ⁰ mode to estimate the inductive scale lengthC in the semiannual period, the value ofC at each observatory would be biased significantly. The purpose of this study is to find which kind of modes is optimal for estimating the values ofC corresponding to the semiannual variations. The results show that a composite mode, involving five terms P _n ⁰ (n = 1,, 5), might be a reasonable and acceptable one  相似文献   

Exact two-soliton solutions to the Einstein gravitational field equations     

F. T. To  P. C. W. Fung  C. Au 《Astrophysics and Space Science》1991,184(2):313-330

Following our previous work on the existence of 1-soliton solution to the Einstein gravitational field equations in the presence of a spherically-symmetric static background field, we have found six sets of analytical 2-soliton solutions to the Einstein field equations under a certain ansatz in the absence of the stated background field. Numerical analysis shows that if the two solitons of the transverse nature are injected at space variable z±, the longitudinal field componentg ₃₃ will acquire non-zero values for a bounded spatial region at later time. The nature of the solitons becomes rather complex when they interact. The amplitudeg of each soliton may change its magnitude resulting from the interaction. We have found that we might interpret the evolution of one field component as the gravitational instanton in our solutions. We must remark also that the total energy of the interacting solitons remains constant, as expected, at all time. These solutions correspond to the situation where the Riemann tensor is in general non-zero and are truly non-trivial solutions.  相似文献   

Spectral analysis of cyclotron radiation in anisotropic plasmas     

P. L. Leung  P. C. W. Fung 《Astrophysics and Space Science》1989,151(2):293-306

Following up our previous analysis of cyclotron radiation in anisotropic plasmas, we derived expression for the power received at a far field point per unit frequency range along the group velocity direction dP(, )/d. We then carry out a series of numerical analysis presenting the spectral features rather than directional features of cyclotron radiation. In particular, we analyse the power received per unit solid angle per unit frequency range d² P(, )/(d d). It is expected the analysis result presented here can be compared directly with observation for parameters pertaining to astrophysical plasmas in stellar and terrestrial atmospheres.  相似文献