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171.
The Eaux-Bonnes landslide (Western Pyrenees,France): overview of possible triggering factors with emphasis on the role of groundwater 总被引:2,自引:0,他引:2
The purpose of this study is to achieve an understanding of the failure mechanisms which caused the Eaux-Bonnes landslide.
The geological investigations carried out on the slope of the landslide showed that the sliding mass was cut by numerous faults.
The factors controlling the landslide failure were complex, and it is known that neither earthquakes nor heavy precipitation
could have triggered the disruption. The groundwater within the solid rock mass has been surveyed, because significant precipitation
events during the 2 years preceding the beginning of the paroxysmal phase of the landslide could have led to an increase in
pore water pressure along these fractures, thereby triggering the landslide. In order to achieve a full understanding of the
failure mechanism, and to identify the origin of the groundwater, a hydrogeochemical survey was carried out over a period
of 1 year. The results reveal the existence of high sulphate concentrations in the groundwater originating in springs located
at the bottom of the landslide. The sulphate concentrations are correlated with high calcium concentrations, and clearly indicate
the presence of gypsum in the vicinity of the lower reaches of the landslide. The presence of gypsum in this area of the Pyrenees
suggests that deep groundwater played a role in triggering the landslide. 相似文献
172.
The existence of spikes with very short time scales (1 to 10 ms) in the decimetric radio spectrum emphasizes the necessity of building radio instruments with very high time resolution. Therefore, we are planning to build a multi-frequency decimetric radioheliograph at the radioastronomical station of the Observatoire Royal de Belgique (Humain, Belgium). The existing array primarily devoted to observe at 408 MHz will constitute the starting structure of the project.Paper presented at the 4th CESRA workshop in Ouranopolis (Greece) 1991 相似文献
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174.
Human thermal perception is best described through thermal indices. The most popular thermal indices applied in human bioclimatology are the perceived temperature (PT), the Universal Thermal Climate Index (UTCI), and the physiologically equivalent temperature (PET). They are analysed focusing on their sensitivity to single meteorological input parameters under the hot and windy meteorological conditions observed in Doha, Qatar. It can be noted, that the results for the three indices are distributed quite differently. Furthermore, they respond quite differently to modifications in the input conditions. All of them show particular limitations and shortcomings that have to be considered and discussed. While the results for PT are unevenly distributed, UTCI shows limitations concerning the input data accepted. PET seems to respond insufficiently to changes in vapour pressure. The indices should therefore be improved to be valid for several kinds of climates. 相似文献
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Fr. W. Pollin 《International Journal of Earth Sciences》1926,17(5):369-377
Ohne Zusammenfassung 相似文献
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