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Martin Mergili Wolfgang Fellin Stella M. Moreiras Johann Stötter 《Natural Hazards》2012,61(3):1051-1081
A GIS-based model framework, designed as a raster module for the Open Source software GRASS, was developed for simulating
the mobilization and motion of debris flows triggered by rainfall. Designed for study areas up to few square kilometres, the
tool combines deterministic and empirical model components for infiltration and surface runoff, detachment and sediment transport,
slope stability, debris flow mobilization, and travel distance and deposition. The model framework was applied to selected
study areas along the international road from Mendoza (Argentina) to Central Chile. The input parameters were investigated
at the local scale. The model was run for a number of rainfall scenarios and evaluated using field observations and historical
archives in combination with meteorological data. The sensitivity of the model to a set of key parameters was tested. The
major scope of the paper is to highlight the capabilities of the model—and of this type of models in general—as well as its
limitations and possible solutions. 相似文献
66.
Solar prominences have been simultaneously observed in the integrated light of the He D3 and the Hβ emissions on two successive days, using the SST on La Palma with its tip-tilt mirror locked on a nearby white-light
limb facular grain. The spatial and the temporal variation of the integrated line intensities and their ratio shows mainly
two characteristics: (A) Constant emission ratio (even) in regions with substantial intensity variations and (B) varying emission
ratio (often) tightly related to intensity structures of the prominence. (A) May be explained by a different number of superposing
threads along the line of sight having very similar physical state. (B) Indicates threads with different intrinsic physical
states; these may depend on the gas pressure or the inner structure of each thread, i.e., the “packing density,” affecting the penetration of ionizing EUV radiation, which affects the He i level populations and thus the rate of the triplet excitation. 相似文献
67.
Johann G. Raith 《Mineralogy and Petrology》2004,82(3-4):I-III
68.
Johann Steiner 《Australian Journal of Earth Sciences》2013,60(1):99-131
Present‐day galactic data permit the construction of a galactic model in which the galactic gravitational field is described by a gravitational function rather than the Newtonian gravitational “constant” G. The concept of this empirical gravitational function, which is based on galactic orbital velocity data, envisages G as a function of time and space. In this model the interaction of this gravitational function, which has rotational symmetry in the galactic plane, and the slightly elliptical galactic orbit of the solar system results in a systematic variation of G. This interaction specifies a simple galactic time‐scale which can be conveniently compared with events of the geological time‐scale. For reasons of galactic evolution and modifying effects due to suspected changes of mass distributions in the universe with the passage of time, which are classed here under the Dirac‐Jordan Effect, such a comparison is initially restricted to the past 1#fr1/4> cosmic years, or 350 million years. The problems in extending such a comparison to 8 cosmic years are discussed, and such an extension seems promising, but it is hampered by the paucity of geological and geophysical data from the lower Palaeozoic and the Precambrian and the present uncertainties in regard to galactic evolution. “Worldwide” statistical maxima and minima of the following geological criteria disclose an episodic correlation with the variation of G and the rates of change of G during the past 350 million years, as specified by this galactic model. It is possible to interpret this correlation in terms of accepted geological principles and concepts in most cases. The following geological phenomena are considered in this comparison of the galactic and geological time‐scales for the past 350 million years.
Period boundaries of the stratigraphic system 相似文献
69.
Christoph Aubrecht Klaus Steinnocher Mario Köstl Johann Züger Wolfgang Loibl 《Natural Hazards》2013,68(3):1371-1384
For assessing the social dimension of vulnerability, population exposure mapping is usually considered the essential starting point. Integration of social structure then further differentiates situation-specific vulnerability patterns on a local scale. Census data available in heterogeneous spatial reference units are still considered the standard information input for assessing potentially affected people, for example, in case of an emergency. There is a strong demand for population data in homogeneous spatial units that are independent from administrative areas. Raster representations meet this demand but are not yet available for all European countries. In this paper, we present an approach of spatial disaggregation of population data for a European transect referring to current population statistics and anticipated future prospects. Recently published data providing the degree of soil sealing are applied as basic proxy for population density in the spatial disaggregation model. In order to assess future patterns of climate change-related vulnerability, results of a European regional climate model are considered for projecting the situation in the 2030s. “Heat wave frequency” is accounted for as climate variable featuring conditions regarded as especially strenuous for elderly or physically weak persons. Integrated analysis of the population and climate prospects enables identification of hot spots in the European transect examined, that is, regions of particularly demanding projected climatic patterns as well as high population density and case-specific vulnerable structure (elderly people). Integrated and consistent spatial analyses on European scale are essential for decision support in the context of climate change impact mitigation as well as for risk communication and future safety and security considerations. 相似文献
70.
Gernot Klammler Hans Kupfersberger Gerhard Rock Johann Fank 《Environmental Earth Sciences》2013,69(2):663-678
The aquifer Westliches Leibnitzer Feld, Austria, is a significant resource for regional and supraregional drinking water supply for more than 100,000 inhabitants, but the region also provides excellent agricultural conditions. This dual use implicates conflicts (e.g., non-point source groundwater pollution by nitrogen leaching), which have to be harmonized for a sustainable coexistence. At the aquifer scale, numerical models are state-of-the-art tools to simulate the behavior of groundwater quantity and quality and serve as decision support system for implementing groundwater protecting measures. While fully and iteratively coupled simulation models consider feedback between the saturated and unsaturated zone, sandy soil conditions and groundwater depths beneath the root zone allow the use of a unidirectional sequential coupling of the unsaturated water flow and nitrate transport model SIMWASER/STOTRASIM with FEFLOW for the investigation area. Considering separated inputs of water and nitrogen into groundwater out of surface water bodies, agricultural, residential and forested areas, first simulation results match observed groundwater tables, but underestimate nitrate concentrations in general. Thus, multiple scenarios assuming higher nitrogen inputs at the surface are simulated to converge with measured nitrate concentrations. Preliminary results indicate that N-input into the groundwater is strongly dominated by contributions of agricultural land. 相似文献