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941.
Rock minerals such as dimension and crushed stones and sands and gravels (aggregates) are indispensable materials for the building and construction industries. The growth in demand for these resources causes intensification of mining operations (and their consequent environmental impacts) and transport problems in regions abundant in rock minerals. The balanced management of these resources by regional policy-makers is difficult as it requires, among other things, comprehensive and up-to-date information on the spatial distribution and temporal changes of available reserves, demand, production, and transport. This information can be provided by means of spatial and temporal analyses through geographic information systems (GIS). In this research, the focus is on the following aspects of rock mineral (aggregates) resources and mining management in the context of regional spatial planning in the example region of Lower Silesia in Poland: the spatial and temporal changes in distribution and intensity of mining, the availability of economic reserves in active mines, the magnitude and distribution of road transport flows of aggregates, the potential of railways as an alternative means of transport, and the valorisation of undeveloped aggregates deposits to assess their suitability for future use. For the purposes of this study, cartographic models have been developed using GIS to facilitate analyses of these mineral resources, mining, and transport. The results of these analyses provide current and comprehensive information on the state of aggregates mineral resources, production and transport in the Lower Silesia region. They also give an insight into availability of rock mineral resources for the future. Knowledge of these processes is important for spatial development planning, especially physical infrastructure, conducted by national, regional, and local governments.  相似文献   
942.
Quantitative landslide risk assessment requires information about the temporal, spatial and intensity probability of hazardous processes both regarding their initiation as well as their run-out. This is followed by an estimation of the physical consequences inflicted by the hazard, preferentially quantified in monetary values. For that purpose, deterministic hazard modelling has to be coupled with information about the value of the elements at risk and their vulnerability. Dynamic run-out models for debris flows are able to determine physical outputs (extension, depths, velocities, impact pressures) and to determine the zones where the elements at risk can suffer an impact. These results can then be applied for vulnerability and risk calculations. Debris flow risk has been assessed in the area of Tresenda in the Valtellina Valley (Lombardy Region, northern Italy). Three quantitative hazard scenarios for different return periods were prepared using available rainfall and geotechnical data. The numerical model FLO-2D was applied for the simulation of the debris flow propagation. The modelled hazard scenarios were consequently overlaid with the elements at risk, represented as building footprints. The expected physical damage to the buildings was estimated using vulnerability functions based on flow depth and impact pressure. A qualitative correlation between physical vulnerability and human losses was also proposed. To assess the uncertainties inherent in the analysis, six risk curves were obtained based on the maximum, average and minimum values and direct economic losses to the buildings were estimated, in the range of 0.25–7.7 million €, depending on the hazard scenario and vulnerability curve used.  相似文献   
943.
Tourmalinization associated with peraluminous granitic intrusions in metapelitic host-rocks has been widely recorded in the Iberian Peninsula, given the importance of tourmaline as a tracer of granite magma evolution and potential indicator of Sn-W mineralizations. In the Penamacor-Monsanto granite pluton (Central Eastern Portugal, Central Iberian Zone), tourmaline occurs: (1) as accessory phase in two-mica granitic rocks, muscovite-granites and aplites, (2) in quartz (±mica)-tourmaline rocks (tourmalinites) in several exocontact locations, and (3) as a rare detrital phase in contact zone hornfels and metapelitic host-rocks. Electron microprobe and stable isotope (δ18O, δD, δ11B) data provide clear distinctions between tourmaline populations from these different settings: (a) schorl–oxyschorl tourmalines from granitic rocks have variable foititic component (X□ = 17–57 %) and Mg/(Mg + Fe) ratios (0.19–0.50 in two-mica granitic rocks, and 0.05–0.19 in the more differentiated muscovite-granite and aplites); granitic tourmalines have constant δ18O values (12.1 ± 0.1 ‰), with wider-ranging δD (?78.2 ± 4.7 ‰) and δ11B (?10.7 to ?9.0 ‰) values; (b) vein/breccia oxyschorl [Mg/(Mg + Fe) = 0.31–0.44] results from late, B- and Fe-enriched magma-derived fluids and is characterized by δ18O = 12.4 ‰, δD = ?29.5 ‰, and δ11B = ?9.3 ‰, while replacement tourmalines have more dravitic compositions [Mg/(Mg + Fe) = 0.26–0.64], close to that of detrital tourmaline in the surrounding metapelitic rocks, and yield relatively constant δ18O values (13.1–13.3 ‰), though wider-ranging δD (?58.5 to ?36.5 ‰) and δ11B (?10.2 to ?8.8 ‰) values; and (c) detrital tourmaline in contact rocks and regional host metasediments is mainly dravite [Mg/(Mg + Fe) = 0.35–0.78] and oxydravite [Mg/(Mg + Fe) = 0.51–0.58], respectively. Boron contents of the granitic rocks are low (<650 ppm) compared to the minimum B contents normally required for tourmaline saturation in granitic melts, implying loss of B and other volatiles to the surrounding host-rocks during the late-magmatic stages. This process was responsible for tourmalinization at the exocontact of the Penamacor-Monsanto pluton, either as direct tourmaline precipitation in cavities and fractures crossing the pluton margin (vein/breccia tourmalinites), or as replacement of mafic minerals (chlorite or biotite) in the host-rocks (replacement tourmalinites) along the exocontact of the granite. Thermometry based on 18O equilibrium fractionation between tourmaline and fluid indicates that a late, B-enriched magmatic aqueous fluid (av. δ18O ~12.1 ‰, at ~600 °C) precipitated the vein/breccia tourmaline (δ18O ~12.4 ‰) at ~500–550 °C, and later interacted with the cooler surrounding host-rocks to produce tourmaline at lower temperatures (400–450 °C), and an average δ18O ~13.2 ‰, closer to the values for the host-rock. Although B-metasomatism associated with some granitic plutons in the Iberian Peninsula seems to be relatively confined in space, extending integrated studies such as this to a larger number of granitic plutons may afford us a better understanding of Variscan magmatism and related mineralizations.  相似文献   
944.
The nature of permafrost and related environmental conditions in the Weichselian Late Pleniglacial and Lateglacial are reconstructed based on the assessment of frost structures that are best documented in the Loess Belt and in plateau areas composed of glacial till. Investigations were conducted in the central‐eastern part of the European Sand Belt (SE Poland and NW Ukraine) on a fluvio‐aeolian sedimentary succession and took into account its chronological context given by luminescence dating. Various generations of periglacial structures found in these deposits indicate not only the development of permafrost (ice‐wedge pseudomorphs) and decreased humidity (composite wedge casts) but also the degradation of permafrost (large‐scale involutions) and, finally, the establishment of deep seasonal frost (frost cracks). The diversity of structures in the study region appears to result from local conditions rather than increasing continentality of climate towards the east.  相似文献   
945.
Abstract

The Kyoto Protocol has an ambitious reporting and review system to assess Parties' compliance with their emission commitments. It is based on a ‘bottom-up’ approach; that is, each Party is required to submit detailed inventories of emissions and removals. This requires considerable resources and may still not detect all important cases of non-compliance. We consider the case for introducing ‘top-down’ methods; that is, independent inverse modelling methods that calculate probable emissions using measured concentrations of gases in the atmosphere and meteorological models. We argue that the top-down methods are at present too inaccurate, too cumbersome, and politically too problematic to serve as independent alternatives to the reported emission inventories for assessing compliance, although they could be useful in monitoring the global success of the protocol. We conclude that these top-down approaches may supplement the traditional emission inventories, in particular those dealing with fluorinated gases, thereby providing input for improving the emission inventory methods.  相似文献   
946.
Vaduvescu  O.  Aznar Macias  A.  Wilson  T. G.  Zegmott  T.  Pérez Toledo  F. M.  Predatu  M.  Gherase  R.  Pinter  V.  Pozo Nunez  F.  Ulaczyk  K.  Soszyński  I.  Mróz  P.  Wrona  M.  Iwanek  P.  Szymanski  M.  Udalski  A.  Char  F.  Salas Olave  H.  Aravena-Rojas  G.  Vergara  A. C.  Saez  C.  Unda-Sanzana  E.  Alcalde  B.  de Burgos  A.  Nespral  D.  Galera-Rosillo  R.  Amos  N. J.  Hibbert  J.  López-Comazzi  A.  Oey  J.  Serra-Ricart  M.  Licandro  J.  Popescu  M. 《Earth, Moon, and Planets》2022,126(2):1-26
Earth, Moon, and Planets - The Perseverance rover (Mars 2020) mission, the first step in NASA’s Mars Sample Return (MSR) program, will select samples for caching based on their potential to...  相似文献   
947.
948.
The landscapes of the world are constantly changing under the influence of human activities leading to the growth of artificial surfaces. The covering of soil by artificial surfaces is referred to as soil sealing. Aerial and satellite images or data derived from them (for instance CORINE land cover — CLC data used here) provide important information that makes it possible to assess the occurrence, area and rate of soil sealing. As the term sealed soil cannot be wholly identified with the content of the appropriate CLC classes, the term land cover flow urbanization (LCFU) will be used here. The essence of this study is the demonstration and documentation of the trends of the LCFU in Europe for the periods 1990–2000 and 2000–2006 on a single map. This may contribute to a better spatial awareness of the ongoing transformation of landscape under the effects of human activities in an pan-European context. Changes in the LCFU can be seen on a map, compiled from 3 × 3 km squares at an all-European scale, using colours and their hues, to fulfil the role both of identification and classification. The colour method employed makes it possible to perceive three groups of LCFU changes on two time horizons, that is, whether the rate of LCFU in 2000–2006 increased or remained the same (hues of red); or dropped compared to the 1990–2000 period (hues of light to dark blue). The third group represents the LCFU with rates higher or lower than the average (countries with changes recorded in only one time horizon are presented in dark and light magenta colours).  相似文献   
949.
The terrigenous fraction of sediments recovered from Walvis Ridge, SE Atlantic Ocean, reveals a history of southwestern African climate of the last 300 kyr. End-member modelling of a data set of grain-size distributions (n=428) results in three end members. The two coarsest end members are interpreted as eolian dust, the third end member as hemipelagic mud. The ratio of the two eolian end members reflects the eolian grain size and is attributed to the intensity of the SE trade winds. Trade winds were intensified during glacials compared to interglacials. Changes in the ratio of the two eolian end members over the hemipelagic one are interpreted as variations in southwestern African aridity. Late Quaternary southwestern African climate was relatively arid during the interglacial stages and relatively humid during the glacial stages, owing to meridional shifts in the atmospheric circulation system. During glacials the polar front shifted equatorward, resulting in a northward displacement of the zone of westerlies, causing increased rainfall in southwestern Africa. The equatorward shift of the polar front is coupled with an increase of the meridional pressure gradient, leading to enhanced atmospheric circulation and increased trade-wind intensity.  相似文献   
950.
Based on observations of polar plume kinematics in the white-light corona during the total solar eclipse in 2006, the images obtained during multi-station observation of the eclipses of 2006, 2008, 2009 and 2010 were analysed. Several polar plumes showing similar kinematics were identified. The speeds of these dynamic features were found by comparing images obtained at different times along the path of totality. A possible connection with erupting spicules and macrospicules is discussed.  相似文献   
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