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1.
2.
通过对1992年河南登封4.7级地震的资料分析,表明拐河老井地下水位变化是区域应力场的变化效应。在时间上有连续性,在空间上和构造体系上有一定的相关性 相似文献
3.
Chemical characteristics of the surface water and algae in lakes in the Seduiyakha River basin are presented. Specific features of components of limnetic ecosystems under the influence of anthropogenic factors in the territory of an oil–gas condensate field are shown. Ambiguous response of algal communities to changes in the aquatic environment is revealed. 相似文献
4.
Shuangtaizi estuarine wetland along the Bohai Sea coast,the biggest bulrush wetland in the world,has been listed in ‘The Record of Important International Wetland Conservation District’. Taking the year of 2 000 as an example,the minimum,the most suitable and the maximum ecological water requirement of Shuangtaizi estuarine wetland are calculated in this paper based on both ecological theory and Geological Information System technology. In addition,the remote sensing technique is adopted in the data acquisi... 相似文献
5.
Shuangtaizi estuarine wetland along the Bohai Sea coast, the biggest bulrush wetland in the world, has been listed in ‘The
Record of Important International Wetland Conservation District’. Taking the year of 2 000 as an example, the minimum, the
most suitable and the maximum ecological water requirement of Shuangtaizi estuarine wetland are calculated in this paper based
on both ecological theory and Geological Information System technology. In addition, the remote sensing technique is adopted
in the data acquisition process. Moreover, the total water requirement and the unit area water requirement for different wetland
types are obtained. The result is very important for water resources planning, ecological conservation and regional agriculture
structure adjustment in Shuangtaizi. Meanwhile, this study can serve as a useful example for calculating the ecological water
requirement in other similar estuarine wetlands. 相似文献
6.
A critical analysis of the methods and results of estimating the optical thickness of the dust component in the Martian atmosphere 0, the particle size r
0, and the imaginary part of the refractive index n
ihas shown the following. (1) Observational data on the brightness distribution over the Martian disk as well as the phase dependences of diffusely reflected light and the azimuthal dependences of diffusely transmitted light are most appropriate to use only for verifying the reliability of the aerosol parameters determined by other methods. (2) If the morning and evening fogs in the atmosphere are disregarded, the Bouguer–Lambert–Beer method used to analyze the solar-brightness attenuation measured on the planetary surface yields overestimated extraatmospheric solar intensity I
0and atmospheric optical depth 0. At the Viking 1landing site, I
0and 0could be overestimated by a factor of 1.7 and by 0.35, respectively. (3) The aerosol size determined by analyzing measurements of the azimuthal dependences for the Martian sky brightness at low elevations of the Sun most likely corresponds to the fog particles. (4) If overestimated values of I
0were used to standardize the observations of the solar radiation transmitted by the Martian atmosphere, then n
iwere also overestimated; using overestimated 0also affected the reliability of the latter. (5) The problem of reliability of the available 0and r
0estimates for periods of high atmospheric transparency is yet to be solved. For the highest activity of the dust storm in 1971, it was found that 4.5 r
0 7.5 m for the lognormal particle size distribution with 2= 0.2 and the optical thickness of a dust cloud 0 15. (6) The spectral values of the apparent albedo of Mars measured in October 1971 at a phase angle of 42° in the spectral range 0.250 0.717 allowed the imaginary part of the refractive index to be estimated in terms of a model of a dust cloud composed of spherical particles with the lognormal size distribution with r
0= 4.5 m and 2= 0.2. 相似文献
7.
Dlugach Zh. M. Korablev O. I. Morozhenko A. V. Moroz V. I. Petrova E. V. Rodin A. V. 《Solar System Research》2003,37(1):1-19
Atmospheric aerosols play an important role in forming the Martian climate. However, the basic physical properties of the Martian aerosols are still poorly known; there are many contradictions in their estimates. We present an analytical overview of the published results and potentialities of various methods. We consider mineral dust. Zonally averaged data obtained from mapping IR instruments (TES and IRTM) give the optical thickness of mineral aerosols 9 = 0.05–0.1 in the 9-m band for quite atmospheric conditions. There is a problem of comparing these estimates with those obtained in the visible spectral range. We suggest that the commonly used ratio vis/9 >2 depends on the interpretation and it may actually be smaller. The ratio vis/9 1 is in better agreement with the IRIS data (materials like montmorillonite). If we assume that vis/9 = 1 and take into account the nonspherical particle shape, then the interpretation of ground-based integrated polarimetric observations ( < 0.04) can be reconciled with IR measurements from the orbit. However, for thin layers, the sensitivity of both methods to the optical thickness is poorly understood: on the one hand, polarimetry depends on the cloud cover and, on the other hand, the interpretation of IR measurements requires that the atmospheric temperature profile and the surface temperature and emissivity be precisely known. For quite atmospheric conditions, the local optical-thickness estimates obtained by the Bouguer–Lambert–Beer method and from the sky brightness measured from Viking 1 and 2 and Mars Pathfinder landers are much larger: = 0.3–0.6. Estimates of the contrasts in images from theVikingorbiters yield the same values. Thus, there is still a factor of 3 to 10 difference between different groups of optical-thickness estimates for the quiet atmosphere. This difference is probably explained by the contribution of condensation clouds and/or by local/time variations. 相似文献
8.
The influence of the shape of dust aerosol particles in the Martian atmosphere on the imaginary part of the refractive index n
i as derived from photometric observations during the period of the highest activity of the dust storm in 1971 was studied and exemplified for particles of spherical and oblate spheroidal shape. A similar analysis was performed for mean particle radii r
0 and optical thicknesses 0 of the dust layer estimated from polarization observations for periods of high atmospheric transparency. It was demonstrated that the values obtained for these optical parameters are affected by the adopted aerosol shape. Namely, the values of n
i, r
0, and 0 found for spheroidal particles proved to be nearly twice as large as those for spheres. However, they are still much less than the available estimates of these parameters inferred, in particular, from interpreting space experiments. The reason for this difference needs further investigation. 相似文献
9.
R. E. Tatevossian A. Ugalde Zh. Ya. Aptekman A. E. Petrosyan 《Izvestiya Physics of the Solid Earth》2006,42(2):124-131
The possibility to obtain a more complete and unbiased long-term history of seismic shakings over large territories than is explicitly reported from inhabited localities is discussed in the paper. An approach proposed for this purpose consists in complementing the spatial distribution of the macroseismic effect of earthquakes by calculated intensities at localities where information on felt shakings is absent. The calculated intensity is obtained on the basis of data on the epicentral intensity and location of epicenters provided by earthquake catalogs. This approach is applied to the analysis of the history of seismic shaking in Spain. The calculated intensities are shown to be comparable in accuracy with the ordinary practice of intensity determinations at national seismological centers. 相似文献
10.
S. S. Arefiev Zh. Ya. Aptekman V. V. Bykova I. V. Matveev A. G. Mikhin S. G. Molotkov K. G. Pletnev V. V. Pogrebchenko 《Izvestiya Physics of the Solid Earth》2006,42(2):167-177
Results derived from processing of data of field observations in the epicentral zone of the Altai earthquake of 2003 are presented. Accurate location of aftershocks showed that their spatial distribution is in good agreement with the source rupture outcropping on the Earth’s surface. According to aftershock data, the source had a length of 75 km and a maximum width of 20 km and extended in the vertical direction for 17 km; the displacement in the source averaged 2.5 m. Clusters identified in the aftershock cloud define variously dipping planes. The location of hypocenters by regional, national, and global seismic networks is not accurate enough to examine spatial features of the aftershocks. 相似文献