Unique documentation,analysis of origin and development of an undrained depression in a subsidence basin caused by underground coal mining (Kozinec,Czech Republic)   总被引：1，自引：0，他引：1  

Marian Marschalko  Işık Yilmaz  David Lamich  Marián Drusa  Darja Kubečková  Tomáš Peňaz  Tereza Burkotová  Vladimír Slivka  Martin Bednárik  David Krčmář  Miloš Duraj  Alena Sochorková 《Environmental Earth Sciences》2014,72(1):11-20

This article aims to explain and demonstrate the origin and development of a subsidence basin caused by coal mining as well as to point out important aspects of this phenomenon in engineering geology. Engineering geology needs to deal with a number of issues related to the origin and development of subsidence basins in areas affected by deep coal mining. An interesting case study from the Upper-Silesian Basin in the northeast of the Czech Republic near the Polish border is presented in this paper. There is a clear time chronological succession in the ground surface changes manifested by a ground subsidence gradation, both in their absolute values as well as in their spatial distribution. The phenomenon is documented by aerial photo time series, which optimally depict the origin and development of the subsidence. In the study area, there are changes in the landscape elements and it is essential to be considered in future land use plans. The marginal conditions of the Quaternary geological structure and hydrogeological conditions are responsible for an unconfined aquifer which manifests there as a water body in an undrained depression in the course of the ground subsidence.  相似文献   

Underground mining hazard map including building site categories in an area affected by underground mining activities   总被引：1，自引：1，他引：0  

Marian?Marschalko  I??k?YilmazEmail author  David?Lamich  Martin?Bednárik 《Environmental Earth Sciences》2014,72(7):2655-2666

The objective of the paper is generation of an underground mining hazard map. The method applied to create the map is based on five categories of areas with different characters of underground mining influence making use of the so-called building site categories. The individual areas with different groups represent various suitability or unsuitability for founding new structures in such influenced territories. They will also reflect a higher or lower degree of influence on already existing structures. Areas affected by underground mining of category V are suitable without any significant restrictions. Areas of the medium category represent influence of building site categories III and IV with economically acceptable measures for founding engineering purposes. The last type is areas with high influence in the category I and II and they are clearly unsuitable for new development. Structures may be founded there in exceptional cases only. This methodology was applied on four map sheets in 1:10,000 scale in a coal mining region in the town of Karviná and its environs in the direction to the City of Ostrava (Czech Republic). Extensive changes caused by underground mining have been identified in the study area and the implementation of the suggested maps may help to deal with the issue in terms of land development by means of land use planning.  相似文献   

Ephemeris time,lunar orbital elements and FK4 equinox correction from the observations of the moon by the method of equal altitudes     

Jan Vondrák  Reviewer L. Webrová 《Studia Geophysica et Geodaetica》1972,16(2):197-200

ma n n¶rt;u u¶rt; u, m um u umuu ¶rt; amaa n nu , a¶rt;a n n a m. am nua ¶rt;a aau a¶rt;u n uumaa u ummna a ¶rt;u amuu 1965–1970 . mama u¶rt;, m na an amua ¶rt;mam ¶rt; m, m um n¶rt;um ¶rt;mam mm.  相似文献   

On the Possibility to Diagnose the Non-Maxwellian ��-Distributions from the Hinode/EIS EUV Spectra     

?. Mackovjak  E. Dzif?��kov��  J. Dud��k 《Solar physics》2013,282(1):263-281

We investigate the possibility to diagnose the ??-distributions from the EUV spectra observed by the Hinode/EIS spectrometer. Observable lines of the most abundant elements except Fe are considered. Synthetic spectra for the ??-distributions with ??=2??C?10 and the Maxwellian distribution were calculated for a range of temperatures and electron densities. We find that only a small number of O, S, Ca, and Ni line ratios are sensitive to???. A?list of the best diagnostic options using transition region and coronal lines is provided. Usually, the line ratios sensitive to ?? are also sensitive to electron density. Weak O?iv lines are a notable exception. These lines offer greatest sensitivity to ?? from all the lines observed by Hinode/EIS. Density diagnostics using lines of the non-Fe elements is discussed and the influence of ?? on the diagnostics of electron density is presented. The density diagnostics using these non-Fe EIS lines are strongly affected by both known and unknown blends. Therefore, we performed the density diagnostics using the Fe?xii??C?xiv lines. Subsequently, these proposed diagnostic methods for ??-distributions are tested using the spectral atlas obtained by Brown et?al. (Astrophys. J. Suppl. 176, 511, 2008). These data do not provide conclusive evidence for the presence of ??-distributions due to possible plasma multitermality, a low observed signal-to-noise ratio, and unremovable or unknown blends.  相似文献   

The Swedish model for groundwater policy: legal foundations, decision-making and practical application     

Jeffrey Lewis  Jan Sjöström  Malin Höök  Bo Sundström 《Hydrogeology Journal》2013,21(4):751-760

Public policy concerning groundwater is often complex, with diverse competing interests. With many countries facing similar challenges, it is instructive to examine the policy approaches that have and have not worked abroad. This article contributes to an international exchange of ideas on how best to approach these common problems by explaining how Sweden regulates its groundwater resources. From constitutional foundations to the practical details associated with applying existing policy, a synopsis is provided of groundwater jurisprudence in Sweden. Multiple governmental agencies are involved with groundwater policy in Sweden; this decentralized approach is probably a function of the natural abundance of clean aquifers throughout the country. Historically, the easy accessibility of high-quality groundwater made it a low priority in the context of environmental policy. It has simply never been an economic necessity to control groundwater resources through a single, unified governmental agency. Sweden is lagging behind many industrialized countries when it comes to implementing policies that protect and manage groundwater. Despite this, there are elements of Sweden’s approach that are highly innovative and possibly unique globally and which therefore merit discussion.  相似文献   

Timing, styles, and kinematics of Cambro–Ordovician extension in the Teplá–Barrandian Unit, Bohemian Massif, and its bearing on the opening of the Rheic Ocean     

Jiří Žák  Petr Kraft  Jaroslava Hajná 《International Journal of Earth Sciences》2013,102(2):415-433

This paper describes late Cambrian dikes and Early Ordovician volcano-sedimentary successions of the Prague Basin, Bohemian Massif, to discuss the timing and kinematics of breakup of the northern margin of Gondwana. Andesitic dikes indicate minor E–W crustal extension in the late Cambrian, whereas the Tremadocian to Dapingian lithofacies distribution and linear array of depocenters suggest opening of this Rheic Ocean rift-related basin during NW–SE pure shear-dominated extension. This kinematic change was associated with the onset of basic submarine volcanism, presumably resulting from decompression mantle melting as the amount of extension increased. We conclude from these inferences and from a comparison with other Avalonian–Cadomian terranes that the rifting along the northern Gondwana margin was a two-stage process involving one major pulse of terrane detachment in the early Cambrian and one in the Early Ordovician. While the geodynamic cause for the former phase remains unclear, but still may include effects of Cadomian subduction (roll-back, slab break-off), isostatic rebound, or mantle plume, the incipient stage of the latter phase may have been triggered by the onset of subduction of the Iapetus Ocean at around 510 Ma, followed by advanced extension broadly coeval (Tremadocian to Darriwilian) in large portions of the Avalonian–Cadomian belt. Unequal amounts of extension resulted in the separation and drift of some terranes, while other portions of the belt remained adjacent to Gondwana.  相似文献   

The symbiotic star CH Cygni – IV. Basic kinematics of the circumstellar matter during active phases     

A. Skopal  M. F. Bode  M. M. Crocker  H. Drechsel  S. P. S. Eyres  R. Kom&#;ík 《Monthly notices of the Royal Astronomical Society》2002,335(4):1109-1119

  相似文献   

Comparison of the Methods of Rock-Microscopic Grain-Size Determination and Quantitative Analysis     

Antal Járai  Miklós Kozák  Péter Rózsa 《Mathematical Geology》1997,29(8):977-991

This study is a methodological investigation of the textural constituents of one- and multicomponent magmatic, sedimentary, and metamorphic rocks as well as artificially cemented composites (concrete, ceramics, etc.) in view of both quantity and grain-size distribution. After the theoretical comparison of the known procedures available (e.g., point counting, measurement along reference lines, planimetry, etc.) the most convenient measurement technique is selected, complemented, then characterized. Most convenient for the dual purpose, with respect to efficiency and standard deviation, is the simple measurement with a scaled cross hairs eyepiece along a reference line. The basic data obtained in this way can be presented both in tables and diagrams. In the area under the cumulative curve demonstrable in the semilogarithmic grain-size-frequency coordinate system, well-known in sedimentology, size-distribution of the constituents can be presented. On the grounds of the individual character of the exact data described, assumptions on the properties, degree of homogeneity, and origin of the material can be drawn. The optimal procedure selected is suitable for computer processing. The texture of the rocks can be characterized with the variable accuracy desired, any unnecessary excess work, and oversize measurement can be avoided. At the same time, an opportunity is opened to check the reliability of earlier measurements performed with different methods or on limited amounts of material (e.g., drill core).  相似文献   

Effect of Flow on Resonant Absorption of Slow MHD Waves in Coronal Arcades     

CsÍk  Árpád  Erdélyi  Róbert  Čadež  Vladimir M. 《Solar physics》1997,172(1-2):61-68

Resonant absorption of slow MHD waves is studied numerically by using the SGH method and is applied to a model of a coronal arcade in the presence of equilibrium plasma flows. The arcade is approximated by a 1D horizontal magnetic slab that is non-uniform along the vertical direction and which is surrounded by two homogeneous media. While propagating from the photosphere upwards into the corona, the magneto-acoustic waves can be resonantly absorbed in the inhomogeneous region of the arcade. Computational results show that the resonant absorption of the impinging waves strongly depends on the equilibrium model and on the characteristics of the driving wave. The results also indicate that the presence of an equilibrium plasma flow along the magnetic field of the arcade reduces the resonant absorption for the flow speed parameters considered.  相似文献   

Multi-Wavelength Analysis of the 29 September 2002 M2.6/2N Flare     

Kulinová  Alena  Dzifčáková  Elena  Bujňák  Rastislav  Karlický  Marian 《Solar physics》2004,221(1):101-119

Using TRACE EUV 171 Å line, Hα line, Zürich radio, RHESSI, and HXRS observations the 29 September 2002 flare (M2.6), which occurred in AR NOAA 0134, was analyzed. Flaring structures were compared with a potential magnetic field model (field lines and quasi-separatrix layers) made from SOHO/MDI full-disk magnetogram. Series of high-resolution SOHO/MDI magnetograms and TRACE white-light images were used to find changes in the active region at the photosphere during the flare. The flare began with a rising of a small dark loop followed by the flare brightening observed in 171 Å with TRACE and Hα lines. In radio wavelengths, first type III bursts were observed 5 min prior to the start of hard X-ray emission, indicating a pre-flare coronal activity. The main hard X-ray emission peak (at 06:36 UT) was associated with the second type III burst activity and several slowly negatively drifting features, all starting from one point on the radio spectrum (probably a shock propagating through structures with different plasma parameters). After this time a huge loop formed and three minutes later it became visible in absorption both in Hα and 171 Å EUV lines. The phase of huge dark loop formation was characterized by long-lasting, slowly negatively drifting pulsations and drifting continuum. Finally, considering this huge loop as a surge an evolution of the event under study is discussed.  相似文献