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31.
32.
Gravitational spreading of mountain ridges displays primary disequilibrium of flysch mountain areas of the Czech Carpathians.
The progression of various types of mass movements is a product of long-term ridge disintegration and is predisposed by the
geological structure of the area and the upper Tertiary-Quaternary morphogenesis of the mountain area. Deep-seated slope deformations
are spatially interconnected by the occurrence of some other types of slope deformations (e.g. debris flows, debris slides,
slumps, rock avalanches, etc.), which pose a considerable risk for the existence of human society. An important causative
factor in these dynamically developing hazardous processes is, among other factors, the way in which land has been used in
the last three centuries. Therefore, the occurrence of various types of slope deformations is studied in terms of their relation
to deep-seated gravitational deformations and in terms of other limiting factors (structural geological, morphological and
climatic factors, manmade impacts, etc.). The paper presents several case studies of slope deformations (Velká Čantoryje Mt,
Lysá hora Mt, Ropice Mt and Smrk Mt) in the area of the Outer Carpathians within the territory of the Czech Republic and also
adverts to some consequences in terms of the socioeconomic structure of the landscape. 相似文献
33.
Stephan Lowitzer Dan J. Wilson Björn Winkler Victor Milman Julian D. Gale 《Physics and Chemistry of Minerals》2008,35(3):129-135
Knowledge of the defect properties of Lunar and Mercurian minerals has recently become important, with the advent of models
which attempt to explain the formation of the thin exosphere of these celestial bodies. Here, we have calculated the formation
energies of sodium and oxygen vacancies in the mineral albite (NaAlSi3O8), as well as the Schottky defect energy for the removal of a Na2O unit. We have employed both the supercell and Mott–Littleton approaches, using Kohn–Sham density functional theory and classical
interatomic potential methods. As well as reporting the defect energies and structures, we comment upon the relative merits
of the methods used. 相似文献
34.
Until the mid-1980s, transport policy was considered by many as one of the least successful domains of the European integration project. However, from the early 1990s onwards, there are clear signs of a single European transport policy, along with the accompanying implementation of infrastructure projects. What is the explanation for such a change in pace? This paper aims to offer insight in these processes by looking at the mechanisms which form and transform this policy domain. To understand the state of a policy domain and its dynamics over time an institutional approach is taken. Two concepts in political science, ‘policy arrangements’ and ‘supranational governance’ are combined and used as a framework to analyse the European transport policy domain. This analysis describes the development of several elements: organisations, rules, the transnational society, power, resources, and the central transport discourse. It demonstrates that all of these elements have developed from an intergovernmental setting towards a more supranational one. This development was slow in the first decennia when European transport policy was rather passive, but it picked up speed in the 1980s and 1990s. In the pivotal year of 1985, pressure from the transnational society resulted in a rapid change of the rules, the resources and the discourse. 相似文献
35.
The Nordic geological surveys: Geology for society in practice 总被引:1,自引:0,他引:1
Morten Smelror Andreas AhlstrФm Lena Ekelund Jens Morten Hansen Keijo Nenonen Anette K. Mortensen 《《幕》》2008,31(1):193-200
Since the mid-nineteenth century., when the first of the Nordic Geological Surveys were established, they have generated a substantial amount of information on the Earth's crust, its natural resources, its processes, and on the geological history of Nordic areas. The collective mission of the geological surveys is to carry out "Geology for Society", by doing research and providing services, and by making geological information and data easily accessible to all the varied end users in industry, government agencies, government institutes, public administrations, technical offices, academia and research institutes, as well as for private individuals. The present paper gives a brief overview of a few, selected, research areas and projects currently undertaken by the Nordic geological surveys. These serve as practical examples of how the Nordic geological surveys address important societal problems and challenges that require geological input for their solution. 相似文献
36.
Two algorithms for in-situ detection and identification of vertical free convective and double-diffusive flows in groundwater
monitoring wells or boreholes are proposed. With one algorithm the causes (driving forces) and with the other one the effects
(convection or double-diffusion) of vertical transport processes can be detected based on geophysical borehole measurements
in the water column. Five density-driven flow processes are identified: thermal, solutal, and thermosolutal convection leading
to an equalization, as well as saltfingers and diffusive layering leading to an intensification of a vertical density gradient.
The occurrence of density-driven transport processes could be proven in many groundwater monitoring wells and boreholes; especially
shallow sections of boreholes or groundwater monitoring wells are affected dramatically by such vertical flows. Deep sections
are also impaired as the critical threshold for the onset of a density-driven flow is considerably low. In monitoring wells
or boreholes, several sections with different types of density-driven vertical flows may exist at the same time. Results from
experimental investigations in a medium-scale testing facility with high aspect ratio (height/radius = 19) and from numerical
modeling of a water column agree well with paramters of in-situ detected convection cells. 相似文献
37.
National flood discharge mapping in Austria 总被引:5,自引:0,他引:5
This article presents the approach and the results of a study in which 30, 100 and 200 year return period flood discharges
were estimated for 26,000 km of Austrian streams. Three guiding principles were adopted: combination of automatic methods
and manual assessments by hydrologists to allow speedy processing and account for the local hydrological situation; combination
of various sources of information including flood peak samples, rainfall data, runoff coefficients and historical flood data;
and involvement of the Hydrographic Services to increase the accuracy and enhance the acceptance of results. The flood discharges
for ungauged catchments were estimated by the Top-kriging approach with manual adjustment to the local flood characteristics.
The adopted combination approach proved to be very efficient both in terms of the project time required and in terms of the
accuracy and acceptability of the estimated flood discharges of given return periods. 相似文献
38.
39.
Ohne Zusammenfassung 相似文献
40.
F. Steinhauser O. Burkard W. Mörikofer M. Toperczer 《Meteorology and Atmospheric Physics》1962,13(2):290-304
Ohne Zusammenfassung 相似文献