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151.
In the initial period of mining activities in the Idrija basin (the16th and the first half of the17th centuries), Hg ore processing was performed at various small-scale roasting sites in the woods surrounding Idrija, by roasting ore in earthen vessels. The recovery rate of this method was very low; about half of Hg was lost, causing soil contamination and considerable amounts of waste material that could potentially leach Hg into the surrounding environment. The main aims of present geochemical study were to determine the contents, vertical distribution and speciation of Hg in soils at the roasting site at Frbej?ene trate in order to verify the extreme pollution of ancient Hg ore roasting sites in the Idrija area and to establish their significance in the wider spatial contamination of soils and aquatic systems. Soil sampling was performed at the area of the former roasting site. The organic matter-rich surface soil layer (SOM) and underlying mineral soil were sampled at 63 sampling locations. Mercury speciation was performed using Hg thermo-desorption-AAS to distinguish cinnabar from potentially bioavailable forms. The results indicate extremely high Hg concentrations with a maximum of 37,000 mg/kg in SOM and 19,900 mg/kg in mineral soil. The established Hg median in soil was 370 mg/kg and in SOM 96.3 mg/kg. Spatial distributions of Hg in SOM and soil showed very high Hg contents in the central area and decreased rapidly with distance. The results of Hg thermo-desorption measurements indicated the presence of cinnabar (HgS) and Hg bound to organic or mineral soil matter. A significant portion (35–40%) of Hg in the investigated soil and SOM samples was comprised of non-cinnabar compounds, which are potentially bioavailable. It has been shown that soils contain high amounts of potentially transformable non-cinnabar Hg, which is available for surface leaching and runoff into the surrounding environment. Therefore, contaminated soils and roasted residues at the studied area are important for persistent Hg release into the aquatic ecosystem. 相似文献
152.
Meteorological effects on seasonal displacements of the ?knes rockslide, western Norway 总被引:1,自引:1,他引:0
In the alpine topography along one of the long fjords with steep and high mountain sides in western Norway the large ?knes
rockslide area is defined by a distinct back scarp rising from 800 to 1,000 m a.s.l. In 2004, an extensive monitoring program
started, including establishment of a meteorological station above the upper tension crack, 900 m a.s.l. This paper evaluates
the significance of meteorological conditions affecting the displacements recorded by five extensometers and two laser sensors
in the tension crack from November 2004 to August 2008. Meteorological factors of importance for the recorded activity in
the tension crack are found to be melt water in spring and large temperature fluctuations around the freezing point in spring,
autumn, and early winter. The records show less acceleration phases in the measured distance across the tension crack in the
second half of the analyzed period even though annual displacements are increasing, indicating that other processes, like
disintegration of irregularities along unfilled joints and disintegration of intact rock bridges in the sliding plane have
become more important. 相似文献
153.
Key factors affecting the future provision of tree-based forest ecosystem goods and services 总被引:1,自引:0,他引:1
The continuous provisioning of forest ecosystem goods and services (EGS) is of considerable interest to society. To provide insights on how much EGS provision will change with a changing climate and which factors will influence this change the most, we simulated forest stands on six climatically different sites in Central Europe under several scenarios of species diversity, management, and climate change. We evaluated the influence of these factors on the provision of a range of tree-based EGS, represented by harvested basal area, total biomass, stand diversity, and productivity. The most influential factor was species diversity, with diverse forest stands showing a lower sensitivity to climate change than monocultures. Management mainly influenced biomass, with the most intensively managed stands retaining more of their original biomass than others. All three climate-change scenarios yielded very similar results. We showed that (1) only few factor combinations perform worse under climate-change conditions than others, (2) diversity aspects are important for adaptive management measures, but for some indicators, management may be more important than diversity, and (3) at locations subject to increasing drought, the future provision of EGS may decrease regardless of the factor combination. This quantitative evaluation of the influence of different factors on changes in the provision of forest EGS with climate change represents an important step towards the design of more focused adaptation strategies and highlights key factors that should be considered in simulation studies under climate change. 相似文献
154.
Analysis of lightning-induced forest fires in Austria 总被引:1,自引:0,他引:1
Mortimer M. Müller Harald Vacik Gerhard Diendorfer Alexander Arpaci Herbert Formayer Hartmut Gossow 《Theoretical and Applied Climatology》2013,111(1-2):183-193
Besides human-caused fires, lightning is the major reason for forest fire ignition in Austria. In order to analyse the causes of ignition and to characterise lightning-induced forest fires, fire records were compared with the real appearance of lightning events by using the Austrian Lightning Detection and Information System for the period from 1993 to 2010. A probability was estimated for each forest fire being caused by lightning by using a decision tree and decision matrices based on flash characteristics (e.g. amplitude, time, location). It could be shown that 15 % of documented forest fires were lightning-caused. Nearly all lightning-caused fires were found during the summer months, whereas almost 40 % of all fires occurring from June to August were naturally caused. Most lightning-caused fires took place in the south and east of Austria. Lightning fires were more frequent at higher altitudes and primarily affected conifer forests. The median burned area was lower than that for anthropogenic forest fires. 相似文献
155.
Alexander Arpaci Chris S. Eastaugh Harald Vacik 《Theoretical and Applied Climatology》2013,114(3-4):393-406
The interpretation and communication of fire danger warning levels based on fire weather index values are critical for fire management activities. A number of different indices have been developed for various environmental conditions, and many of them are currently applied in operational warning systems. To select an appropriate combination of such indices to work in different ecoregions in mountainous, hilly and flat terrain is challenging. This study analyses the performance of a total of 22 fire weather indices and two raw meteorological variables to predict wildfire occurrence for different ecological regions of Austria with respect to the different characteristics in climate and fire regimes. A median-based linear model was built based on percentile results on fire days and non-fire days to get quantifiable measures of index performance using slope and intercept of an index on fire days. We highlight the finding that one single index is not optimal for all Austrian regions in both summer and winter fire seasons. The summer season (May–November) shows that the Canadian build-up index, the Keetch Byram Drought Index and the mean daily temperature have the best performance; in the winter season (December–April), the M68dwd is the best performing index. It is shown that the index performance on fire days where larger fires appeared is better and that the uncertainties related to the location of the meteorological station can influence the overall results. A proposal for the selection of the best performing fire weather indices for each Austrian ecoregion is made. 相似文献
156.
A five-member ensemble of regional climate model (RCM) simulations for Europe, with a high resolution nest over Germany, is analysed in a two-part paper: Part I (the current paper) presents the performance of the models for the control period, and Part II presents results for near future climate changes. Two different RCMs, CLM and WRF, were used to dynamically downscale simulations with the ECHAM5 and CCCma3 global climate models (GCMs), as well as the ERA40-reanalysis for validation purposes. Three realisations of ECHAM5 and one with CCCma3 were downscaled with CLM, and additionally one realisation of ECHAM5 with WRF. An approach of double nesting was used, first to an approximately 50 km resolution for entire Europe and then to a domain of approximately 7 km covering Germany and its near surroundings. Comparisons of the fine nest simulations are made to earlier high resolution simulations for the region with the RCM REMO for two ECHAM5 realisations. Biases from the GCMs are generally carried over to the RCMs, which can then reduce or worsen the biases. The bias of the coarse nest is carried over to the fine nest but does not change in amplitude, i.e. the fine nest does not add additional mean bias to the simulations. The spatial pattern of the wet bias over central Europe is similar for all CLM simulations, and leads to a stronger bias in the fine nest simulations compared to that of WRF and REMO. The wet bias in the CLM model is found to be due to a too frequent drizzle, but for higher intensities the distributions are well simulated with both CLM and WRF at the 50 and 7 km resolutions. Also the spatial distributions are close to high resolution gridded observations. The REMO model has low biases in the domain averages over Germany and no drizzle problem, but has a shift in the mean precipitation patterns and a strong overestimation of higher intensities. The GCMs perform well in simulating the intensity distribution of precipitation at their own resolution, but the RCMs add value to the distributions when compared to observations at the fine nest resolution. 相似文献
157.
Of solar collectors,wind power,and car sharing: Comparing and understanding successful cases of grassroots innovations 总被引:1,自引:0,他引:1
Grassroots activities so far have not been sufficiently appreciated as sources of innovation. Transition processes towards more sustainable socio-technical energy, transport or production systems, however, are hardly imaginable without a broader participation of engaged citizens. This paper presents and compares three cases of successful grassroots innovations for sustainability. In particular we compare the development of wind technology in Denmark, the solar collector do-it-yourself movement in Austria, and the development of car sharing in Switzerland. The paper aims at a better understanding of the preconditions, patterns of growth and change and factors of success of grassroots innovations for more sustainable socio-technical regimes such as energy and transport. In the analysis we focus on dimensions such as the structural conditions and resources of origin, motivations of social actors involved, learning processes and outcomes, competences and activities of those actors, processes of institution-building, and the relationships to mainstream market actors. Based on the empirical background the paper discusses implications for the theorisation of grassroots innovations for greater sustainability and draws implications for further research. 相似文献
158.
159.
160.
Features of the physical oceanographic conditions of the Barents Sea 总被引:17,自引:2,他引:15
Harald Loeng 《Polar research》1991,10(1):5-18