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11.
This paper investigates whether an inefficient allocation of abatement due to constraints on the use of currently available low carbon mitigation options can promote innovation in new technologies and have a positive impact on welfare. We focus on the case of a nuclear power phase-out and endogenous technical change in energy efficiency and alternative low carbon technologies. The research is inspired by the re-thinking about nuclear power deployment which took place in some countries, especially in Western Europe, after the Fukushima accident in March 2011. The analysis uses an Integrated Assessment Model, WITCH, which features multiple externalities related to greenhouse gas emissions and innovation market failures. Our results show that phasing out nuclear power stimulates R&D investments and deployment of technologies with large learning potential. The resulting technology benefits that would not otherwise occur due to intertemporal and international externalities almost completely offset the economic costs of foregoing nuclear power. The extent of technology benefits depends on the stringency of the climate policy and is distributed unevenly across countries. 相似文献
12.
Assessment of rockfall susceptibility by integrating statistical and physically-based approaches 总被引：7，自引：1，他引：6
In Val di Fassa (Dolomites, Eastern Italian Alps) rockfalls constitute the most significant gravity-induced natural disaster that threatens both the inhabitants of the valley, who are few, and the thousands of tourists who populate the area in summer and winter.To assess rockfall susceptibility, we developed an integrated statistical and physically-based approach that aimed to predict both the susceptibility to onset and the probability that rockfalls will attain specific reaches. Through field checks and multi-temporal aerial photo-interpretation, we prepared a detailed inventory of both rockfall source areas and associated scree-slope deposits. Using an innovative technique based on GIS tools and a 3D rockfall simulation code, grid cells pertaining to the rockfall source-area polygons were classified as active or inactive, based on the state of activity of the associated scree-slope deposits. The simulation code allows one to link each source grid cell with scree deposit polygons by calculating the trajectory of each simulated launch of blocks. By means of discriminant analysis, we then identified the mix of environmental variables that best identifies grid cells with low or high susceptibility to rockfalls. Among these variables, structural setting, land use, and morphology were the most important factors that led to the initiation of rockfalls.We developed 3D simulation models of the runout distance, intensity and frequency of rockfalls, whose source grid cells corresponded either to the geomorphologically-defined source polygons (geomorphological scenario) or to study area grid cells with slope angle greater than an empirically-defined value of 37° (empirical scenario). For each scenario, we assigned to the source grid cells an either fixed or variable onset susceptibility; the latter was derived from the discriminant model group (active/inactive) membership probabilities.Comparison of these four models indicates that the geomorphological scenario with variable onset susceptibility appears to be the most realistic model. Nevertheless, political and legal issues seem to guide local administrators, who tend to select the more conservative empirically-based scenario as a land-planning tool. 相似文献
13.
Species–energy theory predicts a positive relationship between species richness and energy. The mechanism assumed by this theory is that high energy promotes high population abundance, which in turn promotes high species richness. Evaluations of this mechanism have rendered conflicting evidence, suggesting that more effort is needed to understand the theory’s limitations. Several studies have addressed these limitations, contributing to expand the theory’s scope by incorporating energy variation, whereas others have demonstrated scale dependence of the more individuals hypothesis. We propose that another limitation of this theory is related to its application to groups of species with strong habitat specificity. We suggest that the expected relationship between energy and richness is not necessarily positive at large scales for groups of species adapted to harsh environments. Using data on tenebrionid beetles from arid areas of southern South America, we contrasted four hypotheses that lead to contrasting predictions about the strength and direction of the species–energy relationship on tenebrionid richness. We found a negative relationship between richness and energy availability. We propose that this negative relationship is the result of a constraint in the mechanisms assumed by species?energy theory because organisms evolve adaptations to survive climatic harshness, which influences population abundances. 相似文献
14.
Christiaan van der Tol Wim Timmermans Chiara Corbari Arnaud Carrara Joris Timmermans Zhongbo Su 《Acta Geophysica》2015,63(6):1516-1539
Three eddy covariance stations were installed at the Barrax experimental farm during the Land-Atmosphere Exchanges (REFLEX) airborne training and measurement campaign to provide ground truth data of energy balance fluxes and vertical temperature and wind profiles. The energy balance closure ratio (EBR) was 105% for a homogeneous camelina site, 86% at a sparse reforestation site, and 73% for a vineyard. We hypothesize that the lower closure in the last site was related to the limited fetch. Incorporating a vertical gradient of soil thermal properties decreased the RMSE of the energy balance at the camelina site by 16 W m?2. At the camelina site, eddy covariance estimates of sensible and latent heat fluxes could be reproduced well using mean vertical profiles of wind and temperature, provided that the Monin—Obukhov length is known. Measured surface temperature and sensible heat fluxes suggested high excess resistance for heat (kB?1 = 17). 相似文献
15.
A system for effectively forecasting flash floods of the Arno River (Tuscany, Italy) should provide a flood warning with 10–12 h of lead time, primarily in order to evacuate the city of Florence. This goal may be achieved by acquiring and processing meteorological and hydrological data in real-time and, accordingly, by releasing alarms at different levels of reliability and concern. Through the application of both procedural language and expert system techniques, a prototype was developed which can readily handle a variety of relevant information and make predictions on flood hazard in Florence. The system was fairly successfully tested by processing simple meteorological data which enable a 24 hour forewarning to be released. 相似文献
16.
Technologies such as Geographical Information Systems (GIS) have raised great expectations as potential means of coping with natural disasters, including landslides. However, several misconceptions on the potential of GIS are widespread. Prominent among these is the belief that a landslide hazard map obtained by systematic data manipulation within a GIS is assumed to be more objective than a comparable hand-made product derived from the same input data and founded on the same conceptual model. Geographical data can now be handled in a GIS environment by users who are not experts in either GIS or natural hazard process fields. The reality of the successful application of GIS within the landslide hazard domain seems to be somewhat less attractive than current optimistic expectations.In spite of recent achievements, the use of GIS in the domain of prevention and mitigation of natural catastrophes remains a pioneering activity. Diffusion of the technology is still hampered by factors such as the difficulty in acquiring appropriate raw data, the intrinsic complexity of predictive models, the lack of efficient graphical user interfaces, the high cost of digitisation, and the persistence of bottlenecks in hardware capabilities.In addition, researchers are investing more in tuning-up hazard models founded upon existing, often unreliable data than in attempting to initiate long-term projects for the acquisition of new data on the causes of catastrophic events. Governmental institutions are frequently involved in risk reduction projects whose design and implementation appear to be governed more by political issues than by technical ones. There is an unfortunate general tendency to search for data which can be collected at low cost rather than attempting to capture the information which most readily explains the causes of a disaster.If the technical, cultural, economic and political reasons for this unhealthy state cannot be adequately tackled, the International Decade for Natural Disaster Reduction will probably come to an end without achieving significant advances in the prediction and control of natural disasters. 相似文献
17.
P. Carrara G. Bordogna M. Boschetti P. A. Brivio A. Nelson D. Stroppiana 《International journal of geographical information science》2013,27(7):781-799
The monitoring of the environment's status at continental scale involves the integration of information derived by the analysis of multiple, complex, multidisciplinary, and large‐scale phenomena. Thus, there is a need to define synthetic Environmental Indicators (EIs) that concisely represent these phenomena in a manner suitable for decision‐making. This research proposes a flexible system to define EIs based on a soft fusion of contributing environmental factors derived from multi‐source spatial data (mainly Earth Observation data). The flexibility is twofold: the EI can be customized based on the available data, and the system is able to cope with a lack of expert knowledge. The proposal allows a soft quantifier‐guided fusion strategy to be defined, as specified by the user through a linguistic quantifier such as ‘most of’. The linguistic quantifiers are implemented as Ordered Weighted Averaging operators. The proposed approach is applied in a case study to demonstrate the periodical computation of anomaly indicators of the environmental status of Africa, based on a 7‐year time series of dekadal Earth Observation datasets. Different experiments have been carried out on the same data to demonstrate the flexibility and robustness of the proposed method. 相似文献
18.
M. Superina F. Fernández Campón E.L. Stevani R. Carrara 《Journal of Arid Environments》2009,73(6-7):683-686
The diet of the pichi armadillo (Zaedyus pichiy) was determined based on analysis of stomach contents of 26 dead individuals confiscated from poachers near Cerro Nevado, Mendoza Province, Argentina. Sand accounted for 66 ± 24% of stomach contents' dry weight. Beetles were the predominant food item in 14 and ants in 5 stomachs, while 5 animals had mainly ingested plant material. The remainder had mostly fed on fly larvae and arachnids. Coleoptera (mainly adults and Scarabeidae larvae) and plant material (seeds, leaves, and roots) were found in all stomachs examined. All pichis had fed on ants of different species and stages, suggesting that pichis eat any ant species they can find and actively prey on nests. Scorpions and spiders were observed in over 60% of stomachs but represented a low aggregate percent weight. Vertebrates were rarely found. Based on these results, the pichi of Mendoza Province can be described as an opportunistic omnivore that mainly feeds on insects and seems to be the least carnivorous of all carnivore–omnivore armadillos. 相似文献
19.
The δD of cellulose from 14C-dated wood, collected in the San Juan Mountains of southwestern Colorado, decreased by about 45‰ from 9600 to 3100 yr B.P. and an additional 25‰ to the present. The wood samples are from trees that grew above present-day tree line and reflect a time of warmer average summer temperatures. These changes in δD are interpreted to indicate a major change during the Holocene in the sources of moisture, in the seasonality of precipitation, or in both. 相似文献
20.