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91.
. A case study is presented in which different probabilistic prediction models (Bayesian probability, fuzzy logic "and", "or", "sum", "product", "gamma" operations, and certainty factors) are used to produce landslide hazard maps for a hilly and mountainous region in the northern Apennines, Italy. Seven data layers are exploited to detect most vulnerable areas: lithology, distance from the geological lineaments, annual rainfall amount, land cover type, topographic slope and aspect, and the distance from hydrographic network segments. The results of the different predictions are compared using the prediction rate index and critically discussed, to evaluate the possibility of using readily available databases for land planning.  相似文献   
92.
The late Pleistocene trachytic Campanian Ignimbrite underlies much of the Campanian Plain near Naples, Italy, and occurs in valleys in the mountainous area surrounding the plain out to about 80 km from its source, the Campi Flegrei caldera. At sites within 15 km of the Campi Flegrei, anisotropy of magnetic susceptibility (AMS) principal directions indicate that, in the absence of significant topography, deposition came from a flow moving in a roughly radial direction. AMS studies of the more distal ignimbrite reveal downhill and/or downvalley flow directions prior to deposition, even where these directions are at high angles to a generally radial transport direction from the vent. On the flanks of Roccamonfina Volcano, flow was directly downhill, as if the source of the ignimbrite was the summit of the volcano. In most localities, the ignimbrite consists of a single massive deposit. In a few localities in the Apennine Mountains, however, the confluence of multiple drainage systems off mountains resulted in multiple local flow units that cannot be correlated between valleys. A detailed study of the ignimbrite in the flat Titerno River valley near Massa shows that the AMS fabrics are not due to late-stage creeping during deposition or compaction. Well-defined, but non-parallel AMS fabrics from vertical and lateral sections in the Massa area are best explained by the merging of gravity currents flowing down the valley and steep valley sides to form a single aggradational deposit. Clast compositions and AMS axes at Mondragone indicate that the pyroclastic flow encountered the Monte Massico massif and was partially blocked, so that flow during deposition was toward the Campi Flegrei. Similar AMS data from sites along the edge of the Campanian Plain indicate back-flow off the first ridge of the Apennine Mountains reached at least 5 km from their base. The Campanian Ignimbrite was deposited from a density-stratified pyroclastic flow. The depositional system consisted of the lower, denser portion of the current, and was controlled by topography. The grouping of the AMS axes is interpreted to indicate that deposition occurred under laminar flow conditions.  相似文献   
93.
Transition countries are expected to become important players in the emerging market for greenhouse gas emission reductions, as they can cut emissions at a relatively low cost. However, the attractiveness of the region as a supplier of emission reductions will not only depend on its cost advantage. It will also depend on the business climate offered to carbon investors—factors like a well-functioning legal and regulatory system, economic and political stability and the capacity to process emission reduction projects efficiently. This paper looks at the carbon investment climate in the transition countries eligible for Joint Implementation (JI)—Russia, Ukraine, Croatia and the EU accession countries. It concludes that JI investors will face a clear trade-off between the scope for cheap JI on the one hand, and the quality of the business environment and JI institutions on the other. The countries with the highest potential for cheap emission reductions also tend to be the countries with the most difficult business climate and the least institutional capacity for JI. The most attractive JI locations may be median countries with a reasonable JI potential and an acceptable business climate, such as Bulgaria, Romania and the Slovak Republic.  相似文献   
94.
95.
The paper discusses model results and then reviews observational data concerning some aspects of the mechanics of mature seismic gaps in coupled subduction zones. The concern is with space-and time-varying stresses, as signalled by the presence and mechanisms of earthquakes in the outer-rise zones adjacent to main thrust areas of large subduction events, and down-dip from such areas, in the downgoing slab. Observations are shown to be consistent with the expectation that in mature seismic gaps, as a result of interplate boundary locking in presence of sustained gravitational driving forces, at least the deeper portions of the ocean plate in the outer-rise zones are under increased compression, and the downgoing slab is under increased tension. The observational data cover two cases of closed seismic gaps, namely the region of the Chilean Valparaiso earthquake of March 3, 1985, and the earthquake of October 4, 1983. Four other cases concern still to-be-closed gaps in northern Chile and along the coast of Guatemala, and also the Kurile Islands Trench gap and the northern New Hebrides gap. It is concluded that the intermediate-term precursor, consisting of a combination of compressional outer-rise earthquake(s) and tensional intermediate-depth, intra-plate events in the downgoing slab, which mechanically signals the latter part of the earthquake cycle, could be useful in evaluating the maturity, and hence great earthquake potential of a seismic gap.  相似文献   
96.
The petrology of the highly phyric two-pyroxene andesitic to dacitic pyroclastic rocks of the November 13, 1985 eruption of Nevado del Ruiz, Colombia, reveals evidence of: (1) increasingly fractionated bulk compositions with time; (2) tapping of a small magma chamber marginally zoned in regard to H2O contents (1 to 4%), temperature (960–1090°C), and amount of residual melt (35 to 65%); (3) partial melting and assimilation of degassed zones in the hotter less dense interior of the magma chamber; (4) probable heating, thermal disruption and mineralogic and compositional contamination of the magma body by basaltic magma “underplating”; and (5) crustal contamination of the magmas during ascent and within the magma chamber. Near-crater fall-back or “spill-over” emitted in the middle of the eruptive sequence produced a small pyroclastic flow that became welded in its central and basal portions because of ponding and thus heat conservation on the flat glaciated summit near the Arenas crater. The heterogeneity of Ruiz magmas may be related to the comparatively small volume (0.03 km3) of the eruption, nearly ten times less than the 0.2 km3 of the Plinian phase of Mount St. Helens, and probable steep thermal and PH2O gradients of a small source magma chamber, estimated at 300 m long and 100 m wide for an assumed ellipsoidal shape.  相似文献   
97.
Lu Wang  Lucia Lo 《GeoJournal》2007,68(2-3):183-194
Acquiring consumer goods and services in the destination country signifies a different type of immigrant experience. This is especially pertinent in world cities where there is a strong presence of ethnic economies and where co-ethnic businesses and mainstream businesses compete against each other. The consumption pattern of immigrants is influenced not only by their pre-migration shopping habits, but also their post-migration transnational behaviour. In this paper, we focus on the consumption experience of Chinese immigrants in Toronto, which hosts one of the largest Chinese ethnic economies outside Asia. Based on a random survey and two focus group discussions, we explore how Chinese immigrants choose between ethnic Chinese and mainstream supermarkets, electronic stores and travel agencies. In theory, Chinese and non-Chinese stores providing similar goods and services are substitutes. The study however reveals intriguing results. Chinese and mainstream travel agencies are substitutes but Chinese and mainstream supermarkets and electronic stores are complements. Such differences reflect the importance of ethnicity and culture in immigrants’ consumption behaviour. The paper provides new evidence on immigrant integration in the domain of consumption and contributes a consumer perspective to the literature on ethnic economy and transnationalism.  相似文献   
98.
This work analyzes how acceptable risk levels are determined in political decisions and related policies in the field of civil protection, i.e., regarding disaster risks and their reduction at the national and supranational level. We examined why establishing the acceptable level of risk is a political decision, and why this decision is not an easy task. Some behavioral elements which can de facto impede such a decision were recognized. Among these, the anomalies inherent in intertemporal choices, availability heuristic and mental accounting play a primary role, because they interfere with preferences for selfish versus others’ interests and with the evaluation of individual versus community gains and losses. Due to these processes, the political decision-maker, unless she is a statesperson, will easily prefer not to decide. Political decision-making, however, could be induced by a change of mind in the voters’ community. This reorientation of the society’s values and interests can be stimulated taking advance from research on social norms, which underlines the role played by some people that drive innovation in a community, e.g., the trendsetters. The scientific, technical and professional communities have the knowledge needed, are aware of the work to be done on the disaster risk reduction and can establish a direct relationship with single trendsetters and statespersons to promote decision-making on disaster risk reduction. Within this relationship, they can build trust, give advice and participate in in-depth discussions. In this interaction and collaboration, behavioral sciences can provide a valuable support for a better reciprocal understanding.  相似文献   
99.
100.
Abstract. Studies on leaf growth and production were performed in two stands, at depths of 5 m and 22m, in the Posidonia oceanica (L.) D elile bed off Lacco Ameno, Ischia (Gulf of Naples). Experiments were carried out in situ from May 1988 to August 1989 at monthly intervals.
Leaf growth and production profiles differed in the two stands investigated. Growth rates were higher at 5 m, with a peak in autumn (5.8 mg · shoot-1· d-1) and another in March (3.8 mg · shoot-1· d-1). At 22 m the maximum rate occurred in May (3.9 mg · shoot-1· d-1). These differential growth rates resulted in a delayed maximum leaf surface and biomass at the deep stand, where lower irradiance values and different temperature patterns were also found. The biomass of epiphytic algae showed trends similar to those of leaves; however, there were remarkable differences in the values between the two stations and for the two investigated years.
The production data of the present study are compared with those of other reports, and it is shown that growth processes are greatly influenced by physical factors.  相似文献   
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