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91.
Jan Hoek Jindich Prach Marek Kíek Petr ída Piotr Moska Petr Pokorný 《Boreas: An International Journal of Quaternary Research》2019,48(4):988-1005
Pronounced climatic warming associated with the Late Weichselian Pleniglacial‐to‐Lateglacial transition caused considerable environmental changes throughout the former periglacial zones (in Europe ~53°–46°N). During permafrost degradation and subsequent ground subsidence (i.e. thermokarst processes), the landscape changed rapidly. In this study we investigated a flat mid‐altitude area in south Bohemia, Czech Republic, lying close to the southern limit of the Weichselian permafrost. We discovered palaeo‐lake basins with sedimentary infillings up to 11 m in depth. According to radiocarbon and palynostratigraphical dating, these basins were formed at the onset of the Late Pleniglacial‐to‐Lateglacial transition, whereas the smaller depressions were formed later. We suggest that the basins resulted from thermal and fluvio‐thermal erosion of the former permafrost and represent remnants of discontinuous gullies and possibly collapsed frost mounds (pingo/lithalsa scars). The formation of this a fossil thermokarst landscape was climatically driven and multiple phased, with the major phase during the climatic warming and wetting at the onset of GI‐1e (Bølling) and the minor phase during GI‐1c (Allerød). This study enhances knowledge of the palaeogeography of the former European periglacial zone by showing that Late Pleistocene thermokarst activity could have had a significant impact on the evolution of the landscape of at least some regions of central Europe along the southern limit of the continuous permafrost zone. The research also points to a similar history for the physical transformation of the landscape of the former European periglacial zone and current thermokarst landscapes and could be a valuable source of information with respect to the future transformation of the Arctic under conditions of ongoing global warming. 相似文献
92.
Wojciech Drzewiecki Piotr Wężyk Marcin Pierzchalski Beata Szafrańska 《Pure and Applied Geophysics》2014,171(6):867-895
In 2011 the Marshal Office of Ma?opolska Voivodeship decided to evaluate the vulnerability of soils to water erosion for the entire region. The quantitative and qualitative assessment of the erosion risk for the soils of the Ma?opolska region was done based on the USLE approach. The special work-flow of geoinformation technologies was used to fulfil this goal. A high-resolution soil map, together with rainfall data, a detailed digital elevation model and statistical information about areas sown with particular crops created the input information for erosion modelling in GIS environment. The satellite remote sensing technology and the object-based image analysis (OBIA) approach gave valuable support to this study. RapidEye satellite images were used to obtain the essential up-to-date data about land use and vegetation cover for the entire region (15,000 km2). The application of OBIA also led to defining the direction of field cultivation and the mapping of contour tillage areas. As a result, the spatially differentiated values of erosion control practice factor were used. Both, the potential and the actual soil erosion risk were assessed quantificatively and qualitatively. The results of the erosion assessment in the Ma?opolska Voivodeship reveal the fact that a majority of its agricultural lands is characterized by moderate or low erosion risk levels. However, high-resolution erosion risk maps show its substantial spatial diversity. According to our study, average or higher actual erosion intensity levels occur for 10.6 % of agricultural land, i.e. 3.6 % of the entire voivodeship area. In 20 % of the municipalities there is a very urgent demand for erosion control. In the next 23 % an urgent erosion control is needed. Our study showed that even a slight improvement of P-factor estimation may have an influence on modeling results. In our case, despite a marginal change of erosion assessment figures on a regional scale, the influence on the final prioritization of areas (municipalities) according to erosion control needs is visible. The study shows that, high-resolution satellite imagery and OBIA may be efficiently used for P-factor mapping and thus contribute to a refined soil erosion risk assessment. 相似文献
93.
The significance of landforms – the contribution of geomorphology to the World Heritage Programme of UNESCO 下载免费PDF全文
Piotr Migoń 《地球表面变化过程与地形》2014,39(6):836-843
This discussion paper addresses the role of geomorphology in designating UNESCO World Heritage properties. Two of the defined criteria employed in the process are explicitly relevant to geomorphology. Criterion (vii) emphasizes the occurrence of superlative natural phenomena, while criterion (viii) directly refers to landforms and on‐going surface processes, along with historical geological values. Superlative natural phenomena may be singular features, but in recent nominations the focus has tended to be on geomorphic diversity over limited areas. Overall, this is a criterion significantly influenced by subjective judgement. The significance of landforms, as included in the wording of criterion (viii), may be considered in three ways. Landforms may be significant for the science of geomorphology itself, and/or for other natural science disciplines, particularly biology and ecology, and/or be of wider cultural significance, including for history, architecture, general landscape aesthetics, art, or religion, underpinning cultural developments. To better determine the conditions to be fulfilled by a property to be considered as geomorphologically significant at the highest global level required for World Heritage listing seems a timely and useful exercise. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
94.
Thermovision is a relatively new method of remote sensing with applications in areas such as military operations, residential monitoring, technological process control and emergency management. Surprisingly, it has not seen much application in environmental studies. The article presents a method of using thermovision for topoclimatic studies. The method is based on the spatial distribution of land surface temperature (LST). The LST distribution indicates the amount of solar energy reaching the Earth surface and depends primarily on terrain shape and land cover types. By analyzing the LST distribution, one can determine spatial topoclimatic variability. The LST derived topoclimatic classification was compared with the theoretical topoclimatic classification based on heat balance. New classes of topoclimates were created and some of the existing types were diversified into more detailed subtypes. The analysis of selected lowland areas in north‐western Poland revealed that both land cover and terrain shape characteristics had a significant impact on the LST distribution, contrary to the expectation of land cover characteristics being more important than terrain shape. The article demonstrates the possibilities of using thermovision in environmental research and presents a new method of topoclimate delimitation based on thermal remote sensing data and geographical information systems (GIS) techniques comparing. The LST classification method with conventional methods based on DEM and land cover analysis. 相似文献
95.
Impact of proximity-adjusted preferences on rank-order stability in geographical multicriteria decision analysis 总被引:1,自引:0,他引:1
This paper presents a new approach to deriving preferences assigned to evaluation criteria in geographical multicriteria decision
analysis. In this approach, the preferences, expressed by numeric weights, are adjusted by distance measures derived from
the explicit consideration of a locational structure. The structure is given by locations of decision options and high importance
reference objects. The approach is demonstrated on the example of a house selection case study in San Diego, California. The
results show that proximity-adjusted preferences for the evaluation criteria can alter significantly the rank order of decision
options. Consequently, the explicit modeling of spatial preference variability may be needed in order to better account for
decision-maker’s preferences. 相似文献
96.
The SW Baltic Sea occupies an area where crustal-scale regional tectonic zones of different age merge and overlap, creating a complex tectonic pattern. This pattern influenced the evolution of the Mesozoic sedimentary basin in this area. We present an interpretation of new high-resolution seismic data from the SW Baltic Sea which provided new information both on modes of the Late Cretaceous inversion of this part of the Danish–Polish Mesozoic basin system as well as on relationship between tectonic processes and syn-tectonic depositional systems. Within the Bornholm–Dar
owo Fault Zone, located between the Koszalin Fault and Christiansø Block, both strike-slip and reverse faulting took place during the inversion-related activity. The faulting was related to reactivation of extensional pre-Permian fault system. Syn-tectonic sedimentary features include a prominent, generally S- and SE-directed, progradational depositional system with the major source area provided by uplifted basement blocks, in particular by the Bornholm Block. Sediment progradation was enhanced by downfaulting along a strike-slip fault zone and related expansion of accommodation space. Closer to the Christiansø Block, some syn-tectonic deposition also took place and resulted in subtle thickness changes within the hinge zones of inversion-related growth folds. Lack of significant sediment supply from the inverted and uplifted offshore part of the Mid-Polish Trough suggests that in this area NW–SE-located marginal trough parallel to the inversion axis of the Mid-Polish Trough did not form, and that uplifted Bornholm Block played by far more prominent role for development of syn-inversion depositional successions. 相似文献
97.
The determination of Fe, Mn, Ni, Pb, Cu, Co, Zn, Cd, K and Na was carried out in the mesozooplankton caught in the southern Baltic in July 1980. The species structure of mesozooplankton was characterized on the basis of mean numbers of particular components and their percentage. The chemical analyses of the samples of mesozooplankton show a wide range of values, although they were within the ranges published for zooplankton from other aquatic regions of the world. Both concentration factors and selectivity factors for Zn, Cd, Pb and Cu in the organisms analysed were calculated. The significant cross-correlation coefficients calculated for all possible pairs of metals showed the following associations: CuPbNiMnFe, MnZn and NaZn. 相似文献
98.
Jan Drzymala Janusz Kapusniak Piotr Tomasik 《International Journal of Mineral Processing》2003,70(1-4):147-155
Potato starch and dextrins resulting from thermolysis of potato starch in the absence of reagents and presence of
-amino acids are promising depressants for separation of lead and copper minerals present in the Polish industrial copper concentrates. The polysaccharides were used for differential xanthate flotation of the final industrial concentrates produced by flotation with sulfhydryl collectors in the absence of depressants. The polysaccharides depressed galena and provided froth concentrate rich in chalcocite and other copper minerals as well as cell product containing lead minerals. The best results of separation were obtained in the presence of plain dextrin prepared by a thermal degradation of potato starch. The industrial concentrate containing 18.5% Cu and 5.5% Pb was divided into a froth product containing 38.1% Cu with 77% recovery of copper and a cell product assaying 7.3% Pb with 83% recovery of lead. It was accomplished using 2500 g/t of dextrin, 50g/t of potassium ethyl xanthate, and 50 g/t of frother (α-terpineol). The pH of flotation was 8.0–8.2. 相似文献
99.
Stanislaw Mazur Magdalena Scheck-Wenderoth Piotr Krzywiec 《International Journal of Earth Sciences》2005,94(5-6):782-798
Several selected seismic lines are used to show and compare the modes of Late-Cretaceous–Early Tertiary inversion within the
North German and Polish basins. These seismic data illustrate an important difference in the allocation of major zones of
basement (thick-skinned) deformation and maximum uplift within both basins. The most important inversion-related uplift of
the Polish Basin was localised in its axial part, the Mid-Polish Trough, whereas the basement in the axial part of the North
German Basin remained virtually flat. The latter was uplifted along the SW and to a smaller degree the NE margins of the North
German Basin, presently defined by the Elbe Fault System and the Grimmen High, respectively. The different location of the
basement inversion and uplift within the North German and Polish basins is interpreted to reflect the position of major zones
of crustal weakness represented by the WNW-ESE trending Elbe Fault System and by the NW-SE striking Teisseyre-Tornquist Zone,
the latter underlying the Mid-Polish Trough. Therefore, the inversion of the Polish and North German basins demonstrates the
significance of an inherited basement structure regardless of its relationship to the position of the basin axis. The inversion
of the Mid-Polish Trough was connected with the reactivation of normal basement fault zones responsible for its Permo-Mesozoic
subsidence. These faults zones, inverted as reverse faults, facilitated the uplift of the Mid-Polish Trough in the order of
1–3 km. In contrast, inversion of the North German Basin rarely re-used structures active during its subsidence. Basement
inversion and uplift, in the range of 3–4 km, was focused at the Elbe Fault System which has remained quiescent in the Triassic
and Jurassic but reproduced the direction of an earlier Variscan structural grain. In contrast, N-S oriented Mesozoic grabens
and troughs in the central part of the North German Basin avoided significant inversion as they were oriented parallel to
the direction of the inferred Late Cretaceous–Early Tertiary compression. The comparison of the North German and Polish basins
shows that inversion structures can follow an earlier subsidence pattern only under a favourable orientation of the stress
field. A thick Zechstein salt layer in the central parts of the North German Basin and the Mid-Polish Trough caused mechanical
decoupling between the sub-salt basement and the supra-salt sedimentary cover. Resultant thin-skinned inversion was manifested
by the formation of various structures developed entirely in the supra-salt Mesozoic–Cenozoic succession. The Zechstein salt
provided a mechanical buffer accommodating compressional stress and responding to the inversion through salt mobilisation
and redistribution. Only in parts of the NGB and MPT characterised by either thin or missing Zechstein evaporites, thick-skinned
inversion directly controlled inversion-related deformations of the sedimentary cover. Inversion of the Permo-Mesozoic fill
within the Mid-Polish Trough was achieved by a regional elevation above uplifted basement blocks. Conversely, in the North
German Basin, horizontal stress must have been transferred into the salt cover across the basin from its SW margin towards
the basins centre. This must be the case since compressional deformations are concentrated mostly above the salt and no significant
inversion-related basement faults are seismically detected apart from the basin margins. This strain decoupling in the interior
of the North German Basin was enhanced by the presence of the Elbe Fault System which allowed strain localization in the basin
floor due to its orientation perpendicular to the inferred Late Cretaceous–Early Tertiary far-field compression. 相似文献
100.
Spatial Prediction of Landslide Hazard Using Fuzzy k-means and Dempster-Shafer Theory 总被引:2,自引:0,他引:2
Landslide databases and input parameters used for modeling landslide hazard often contain imprecisions and uncertainties inherent in the decision‐making process. Dealing with imprecision and uncertainty requires techniques that go beyond classical logic. In this paper, methods of fuzzy k‐means classification were used to assign digital terrain attributes to continuous landform classes whereas the Dempster‐Shafer theory of evidence was used to represent and manage imprecise information and to deal with uncertainties. The paper introduces the integration of the fuzzy k‐means classification method and the Dempster‐Shafer theory of evidence to model landslide hazard in roaded and roadless areas illustrated through a case study in the Clearwater National Forest in central Idaho, USA. Sample probabilistic maps of landslide hazard potential and uncertainties are presented. The probabilistic maps are intended to help decision‐making in effective forest management and planning. 相似文献