A bilinear approximation of the surface relief in terrain correction computations   总被引：2，自引：2，他引：2  

D. Tsoulis  H. Wziontek  S. Petrović 《Journal of Geodesy》2003,77(5-6):338-344

A new method is presented for the computation of the gravitational attraction of topographic masses when their height information is given on a regular grid. It is shown that the representation of the terrain relief by means of a bilinear surface not only offers a serious alternative to the polyhedra modeling, but also approaches even more smoothly the continuous reality. Inserting a bilinear approximation into the known scheme of deriving closed analytical expressions for the potential and its first-order derivatives for an arbitrarily shaped polyhedron leads to a one-dimensional integration with – apparently – no analytical solution. However, due to the high degree of smoothness of the integrand function, the numerical computation of this integral is very efficient. Numerical tests using synthetic data and a densely sampled digital terrain model in the Bavarian Alps prove that the new method is comparable to or even faster than a terrain modeling using polyhedra.  相似文献   

Preliminary seismic hazard maps of Slovenia     

J. K. Lapajne  B. SŠket Motnikar  P. Zupancčicč 《Natural Hazards》1996,14(2-3):155-164

The preparation of the preliminary seismic hazard maps of the territory of Slovenia has been based on an expansion of the basic approach laid out by Cornell in 1968. Three seismic source models were prepared. Two of them are based mainly on the earthquake catalogue using the Poissonian probability model. A map of seismic energy release and a map of earthquake epicenter density are used to delineate seismic sources in these models. The geometry of the third model which is based on a rough estimate of seismotectonic setting is taken from the probabilistic seismic hazard analysis of a nuclear power plant in Slovenia. Published ground motion attenuation models based on strong motion records of recent strong earthquakes in Italy are used. Test maps for variable and uniform b-values are presented. The computer program, Seisrisk III, developed by the U.S. Geological Survey is used.  相似文献   

Croatia — a coastal and maritime country     

Nikola Stražičić 《GeoJournal》1996,38(4):445-453

Croatia, through its geographic position, is a Mediterranean/Adriatic and Central European/Danube state. As an Adriatic coastal state, it has a long maritime tradition, which is apparent in its well-developed shipping (2.4 million GT), the high-quality ship-building industry (among the top six in the world) and through its numerous sea ports, of which many were established in ancient times. The leading national port is Rijeka, which is at the same time an important transit port for Austria, Hungary, Slovakia and the Czech Republic.The exceptionally indented Croatian Adriatic coast with its attractive archipelagos and favorable climatic and oceanographic conditions in the coastal sea offers very advantageous conditions for comprehensive tourist utilization. This is particularly true of nautical tourism, which is complimented by a larger number of constructed and well-equipped yachting ports/marinas on the coast and islands.  相似文献   

The Carpatho-Balkanides and adjacent area: a sector of the Tethyan Eurasian metallogenic belt   总被引：3，自引：1，他引：3  

S. Janković 《Mineralium Deposita》1997,32(5):426-433

The Tethyan Eurasian metallogenic belt (TEMB) was formed during Mesozoic and post-Mesozoic times in the area of the former Tethyan ocean on the southern margin of Eurasia, with the Afro-Arabian and Indian plates to the south. It extends from western Mediterranean via the Alps and southeastern Europe through the Lesser Caucasus, the Hindu Kush, and the Tibet Plateau to Burma and SW Indonesia, linking with the West Pacific metallogenic belt. The Carpatho-Balkan region is one of the sectors of the TEMB, characterized by some specific features. The emplacement of ore deposits is related to a definite time interval, and to specific tectonic settings such as: 1. Late Permian-Triassic intracontinental rifting along the northern margin of Gondwanaland and/or fragments already separated. This setting involves volcanogenic and volcano-sedimentary deposits (iron, lead/zinc, manganese, antimony, mercury, barite), skarn deposits associated with volcano-plutonic complexes of bimodal magmatism, and low temperature carbonate-hosted lead/zinc deposits. 2. Jurassic intraoceanic rifting – ophiolite complexes: This setting hosts major magmatic (particularly podiform chrome deposits) and volcano-sedimentary deposits, mainly of the Cyprus type. 3. Subduction-related setting involves porphyry copper deposits, lesser skarn deposits (iron, locally Pb-Zn), massive sulphide Cu (e.g. Bor) accompanied locally by Pb-Zn of replacement type, epithermal gold deposits, associated with calc-alkaline igneous complexes of the Early Tertiary-Late Cretaceous, and the Neogene gold/silver and base metals deposits. 4. Post-collision continent-continent setting includes deposits of Pb-Zn, Sb, As, Au-Cu associated with volcano-plutonic complexes of calc-alkaline affinity. Several major Alpine metallogenic units are developed in the Carpatho-Balkanides and adjacent area, each characterized by specific development, mineral associations, and types of ore deposits. Received: 3 June 1996 / Accepted: 10 January 1997  相似文献   

Repeated Geodetic Measurements in the West Bohemia Seismoactive Region: Period 1993 - 1996     

Špičák  A.  Mrlina  J.  Jindra  D.  Mervart  L. 《Studia Geophysica et Geodaetica》1997,41(4):319-328

The western part of the Bohemian Massif is characterized by repeated occurrences of intraplate earthquake swarms. To study surface deformations of this anomalous region, a network covering about 2000 square kilometres for repeated geodetic measurements was established in 1993 - 1994. The positions of the individual points of the network were carefully picked with respect to local tectonic structure and earthquake foci distribution. GPS and precise levelling measurements were performed 1-2 times a year. The GPS data were processed by Bernese GPS software. No tendency to any displacement - either horizontal or vertical - of geological blocks was derived from the geodetic data for the period 1993 - 96. Only displacements of less than 5 mm/year in average could occur in the whole region in that period; larger displacements would have been revealed by our measurements.  相似文献   

Appropriate model use for predicting elevations and inundation extent for extreme flood events     

Davor Kvočka  Roger A. Falconer  Michaela Bray 《Natural Hazards》2015,79(3):1791-1808

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Effect of grain‐scale pressure variations on garnet growth: a numerical approach          下载免费PDF全文

X. Zhong  J.C. Vrijmoed  L. Tajčmanová 《Journal of Metamorphic Geology》2017,35(1):19-33

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Sandstone Turning by Abrasive Waterjet     

Petr Hlaváček  Ján Cárach  Sergej Hloch  Karol Vasilko  Dagmar Klichová  Jiří Klich  Dominika Lehocká 《Rock Mechanics and Rock Engineering》2015,48(6):2489-2493

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The response in floodplain respiration of an alpine river to experimental inundation under different temperature regimes          下载免费PDF全文

Tatjana Simčič  Nataša Mori  Christian Hossli  Christopher T. Robinson  Michael Doering 《水文研究》2015,29(26):5438-5450

The respiratory potential [i.e. electron transport system activity (ETSA)] of soils and sediments from five floodplain habitats (channel, gravel, islands, riparian forest and grassland) of the Urbach River, Switzerland, and actual respiration rate (R) of the same samples exposed to experimental inundation were measured. Measurements were carried out at three incubation temperatures (4°C, 12°C and 20°C), and ETSA/R ratios (i.e. exploitation of the overall metabolic capacity) were investigated to better understand the effects of temperature and inundation on floodplain functional heterogeneity. Furthermore, ETSA/R ratios obtained during experimental inundation were compared with ETSA/R ratios from field measurements to investigate the exploitation in total metabolic potential at different conditions. Lowest ETSA and R were measured in samples from channel and gravel habitats, followed by those from islands. Substantially higher values were measured in soils from riparian forest and grassland. Both ETSA and R increased with increasing temperature in samples from all habitats, while the ETSA/R ratio decreased because of a rapid response in microbial community respiration to higher temperatures. The metabolic capacity exploitation (i.e. ETSA/R) during experimental inundation was lowest in predominantly terrestrial samples (riparian forest and grassland), indicating the weakest response to wetted conditions. Comparison of experimentally inundated and field conditions revealed that in rarely flooded soils, the metabolic capacity was less exploited during inundation than during non‐flooded conditions. The results suggest high sensitivity in floodplain respiration to changes in temperature and hydrological regime. ETSA/R ratios are considered good indicators of changes in metabolic activity of floodplain soils and sediments, and thus useful to estimate the impact of changes in hydrological regime or to evaluate success of floodplain restoration actions. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Reply to Comment on “Post‐impact event bed (tsunamite) at the Cretaceous–Palaeogene boundary deposited on a distal carbonate platform interior”          下载免费PDF全文

Tvrtko Korbar  Iain McDonald  Vlasta Premec Fućek  Ladislav Fuček  Hrvoje Posilović 《地学学报》2017,29(5):332-334

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