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91.
92.
Human activity is an important agent defining the contemporary hydrologic cycle. We have documented the potential impacts of impoundment, land use change and climate change on the Zambezi River system in southern Africa and found that they can be substantial. A full analysis requires construction and parameterization of a simulation for the entire catchment. This paper develops a strategy for implementing catchment-scale models of the major hydrologic processes operating within the basin. A coherent data set for calibrating the models has also been assembled. The algorithms consist of a Water Balance (WBM) and a Water Transport (WTM) operating at 1/2o spatial scale and at monthly timesteps. These models transform complex patterns of regional climatology into estimates of soil water, evapotranspiration, runoff, and discharge through rivers of various size. The models are dependent on the characteristics of the terrestrial surface, principally soil texture and land cover. A simulated river network is also required. Additional tabular data sets are essential for model testing and calibration. These include subcatchment areas; observed river discharge at selected points; flooding, storage and loss characteristics of major wetlands; floodwave translation; and, volume, surface area, withdrawal and evaporative losses from impoundments. An important design consideration for the numerous impoundments in the Zambezi requires an understanding of the seasonal variation in discharge, in particular how it might respond to climate and land use change. The research strategy offered here lays a framework for addressing such issues. Although the primary focus of this work is hydrologic, we discuss how the model can be extended to consider constituent transport and biogeochemical cycling issues at the continental scale. 相似文献
93.
Summary The optimization of the method of determining the addition constant of an EDM is discussed. The advantages of the optimization procedure from the point of view of efficiency and improvement of accuracy are reported.
nuuu ¶rt; n¶rt;u a¶rt;¶rt;uu n ¶rt;. u nu n u uu u nu u.相似文献
94.
Vladimír Kropáček Věra Vaňková Reviewer J. Fiala 《Studia Geophysica et Geodaetica》1985,29(3):290-299
Summary The distribution of radioactive(Th, U, K) and selected trace(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) elements in volcanic rocks from the Opole and Jawor regions of the Lower Silesia has been studied. The behaviour of these elements in the studied rocks indicates that the Lower Silesian volcanic rocks are characterized by less differentiated type than other volcanic rocks of the Bohemian Massif, the Opole rock types probably having a less differentiated character than the Jawor rock types.
¶rt;a an¶rt;u a¶rt;uamu(Th, U, K) u m ¶rt;u(Rb, Sr, Ba, Y, Zr, V, Cr, Ni) m auu n¶rt;a am n u u uuu. a n mam n¶rt;num, m aum u uuu n¶rt;mam ¶rt; aamuu n¶rt; u ¶rt;uuau, aum u ana¶rt; uu. au a n¶rt;num, m auu n¶rt; amu n ¶rt;uuau ma ua n¶rt; u amu .相似文献
95.
Sub-surface temperature fields may be considerably affected by active ground water systems, thereby seriously hampering the interpretation of heat flow data. Quantitative evaluation of the convective component of heat transfer is thus very important in cases such as large sedimentary basins with vast underground water circulation. We propose in this study a simple model of horizontal aquifer. This model was used to examine the effect of the lateral convection on the surface heat flow near the recharge zone of basinal margins. The perturbation of the heat flow field above the aquifer was calculated for various aquifer geometry and various flow velocities and the regional scale dependence of the perturbation on the hydraulic properties of the aquifer was demonstrated. The model was applied to the Bohemian Cretaceous Basin and it was shown that within a few kilometres from the recharge zones the observed surface heat flow may be underestimated by up to several tens of percent. The procedure was tested in two locations in this area, in an attempt to make hydrogeological corrections to the measured heat flow values in several boreholes. 相似文献
96.
Pekka Teikari Vladimír Tobyáš Reviewer J. Janský 《Studia Geophysica et Geodaetica》1986,30(3):257-267
Summary The magnification achieved with the standard sine-wave method using seismometers with the calibration and signal coils tightly wound on the same coil former can be erroneous at high frequencies due to the mutual inductance between both coils. An attempt was made to eliminate this influence from the calibration data. The application of theoretical equations was tested with a short-period digital seismograph.
ma¶rt;ama auau aa nu ¶rt;uu ¶rt;uu maauu m m m a u amma ua u a au u¶rt;mumu ¶rt; ua u auau am, u u a¶rt;m n¶rt;m umu. a ¶rt;aa nnma muam auau ¶rt;a. uu mmuu au u¶rt;a nu auauu mnu¶rt;u aa u anu.相似文献
97.
Summary The paper deals with the computation of spherical harmonic coefficients from surface measurements of the magnetic or gravity field of the Earth when the measurements are distributed regularly. The Fourier representation of associated Legendre functions which this procedure makes use of, then enables the harmonic analysis to be transformed to Fourier analysis which has better numerical properties.
ama na ama uu uu uum n nm uu aum uuaumau n u a, ¶rt;a mu uu an ammu ma. ¶rt;mau n a¶rt; , m unm mm n¶rt;¶rt;, nm nmauu aau naam aau , m a¶rt;am uu uumu mau.相似文献
98.
Summary Tests on the vertical vibrating table in the frequency range of70–110 Hz indicate that quartz gravity meters are10–100 times more sensitive at some frequencies than under low-frequency excitation. At high frequencies, the reading beam is at rest and deflected from the correct position. Slow fluctuations of amplitude and frequency near resonance could cause slow irregular motion of the beam with absence of low-frequency ground motion of sufficient intensity.
unmauaum a mua um¶rt; ¶rt;uana amm 70–110u mam, m a m ammaaum 10–100 a mum nu uamm au. u amm au u a¶rt;um n m mu m nu. ¶rt; auauu anum¶rt; u amm au uu aa m am uamm u ua ¶rt;a mmmm uamm au n ¶rt;mam umumu.相似文献
99.
Vladimír Schenk Vít Kárník Zdeňka Schenková Reviewer A. Zátopek 《Studia Geophysica et Geodaetica》1982,26(2):132-144
Summary The distribution of earthquake foci in the crust and the upper mantle indicates the position of mobile zones. Comparing epicentral maps of Central and Eastern Europe, known tectonic lines, results of deep seismic sounding and gravimetric survey enables a scheme of potential seismogenic zones, which correspond to active fault zones separating plates and blocks in the area, to be compiled. The level of earthquake activity varies along the investigated boundaries and can be considered as a measure of the intensity of the present geodynamic processes.Paper presented at the joint symposium AlO of the XVIIth General Assembly of the European Seismological Commission and of the 7th Annual Meeting of the European Geophysical Society, Budapest (Hungary), Aug. 21. – 29., 1980. 相似文献
100.
Summary The routine nulling procedure is modified on the basis of the theoretical decay of transient motion of the gravity meter beam and the time needed for its stabilizing. 相似文献