86 research outputs found
Human populations in the world's mountains: Spatio-temporal patterns and potential controls.
Changing climate and human demographics in the world's mountains will have increasingly profound environmental and societal consequences across all elevations. Quantifying current human populations in and near mountains is crucial to ensure that any interventions in these complex social-ecological systems are appropriately resourced, and that valuable ecosystems are effectively protected. However, comprehensive and reproducible analyses on this subject are lacking. Here, we develop and implement an open workflow to quantify the sensitivity of mountain population estimates over recent decades, both globally and for several sets of relevant reporting regions, to alternative input dataset combinations. Relationships between mean population density and several potential environmental covariates are also explored across elevational bands within individual mountain regions (i.e. "sub-mountain range scale"). Globally, mountain population estimates vary greatly-from 0.344 billion (31%) in 2015. A more detailed analysis using one of the population datasets (GHS-POP) revealed that in âŒ35% of mountain sub-regions, population increased at least twofold over the 40-year period 1975-2015. The urban proportion of the total mountain population in 2015 ranged from 6% to 39%, depending on the combination of population and urban extent datasets used. At sub-mountain range scale, population density was found to be more strongly associated with climatic than with topographic and protected-area variables, and these relationships appear to have strengthened slightly over time. Such insights may contribute to improved predictions of future mountain population distributions under scenarios of future climatic and demographic change. Overall, our work emphasizes that irrespective of data choices, substantial human populations are likely to be directly affected by-and themselves affect-mountainous environmental and ecological change. It thereby further underlines the urgency with which the multitudinous challenges concerning the interactions between mountain climate and human societies under change must be tackled
On-site monitoring for better selection of stone repairs: a case study
Weathering of clay-bearing sandstones does not only depend on material properties but also on the environmental conditions they are exposed to. The same is true for repaired stones, in which the compatibility of the repair mortar should be studied not only in terms of material properties, but also in terms of the climatic conditions it will be sub- jected, in order to maximize this compatibility. This paper proposes a methodology to quantify the thermal and hygric stresses in clay-bearing sandstones and their repair, based on the measurement of temperature and relative humidity at the surface and at several depths in a repaired and a non-repaired stone, as well as wind-driven rain and absorbed water. This is illustrated by a case study in an historical building. The data are used to quantify the stresses in the mate- rials and to propose possible degradation mechanisms.ISSN:2050-744
BioScore: A tool to assess the impacts of European Community policies on Europe's biodiversity
BioScore offers a European biodiversity impact assessment tool. The tool contains indicator values on the ecological preferences of more than 1000 species of birds, mammals, amphibians, reptiles, fish, butterflies, dragonflies, aquatic macro-invertebrates and vascular plants. These values are linked to policy-related pressures and environmental variables
The effect of air pollution on stone decay: the decay of the Drachenfels trachyte in industrial, urban, and rural environmentsâa case study of the Cologne, Altenberg and Xanten cathedrals
Beispiele zum Einfluss der Bildungsbedingungen auf NatĂŒrliche Mischkristallgleichgewichte
Der Artikel zeigt im ersten Beispiel den erheblichen Einfluss des Sauerstoffpartialdruckes auf die Mischkristallbeziehungen im System FeO-FeâOâ-CrâOâ, der trotz eines fixen Fe/Cr-VerhĂ€ltnisses die Bildung davon erheblich abweichender Chromitphasen veranlassen kann.
Im zweiten Beispiel wird gezeigt, dass die bisherigen experimentellen Mischkristalluntersuchungen im pseudobinĂ€ren Sytem PbS-BiâSâ keineswegs dazu angetan sind, zum VerstĂ€ndnis der BildungsvorgĂ€nge der natĂŒrlichen Bleiwismutspiessglanzgruppe beizutragen, die obendrein wegen ihrer geringen Beimengungen von vorwiegend Cu, Fe, Ag und Sb gar nicht in diesem System dargestellt werden kann.
Im dritten Beispiel wird darauf hingewiesen, dass bei der metamorphen Plagioklas-bildung fur deren temperaturabhĂ€ngige Mischkristallzusammensetzung keineswegs nur das Stoffangebot des Gesamtgesteines ausschlaggebend ist. In vielen FĂ€llen lassen sich zwischen der chemischen Zusammensetzung von Plagioklasen und unmittelbar benachbarten Hornblenden Beziehungen aufstellen. Dabei werden die Ca- und Al-, Na- und Si-Gehalte der beiden Phasen entsprechend den physikalisch-chemischen Reaktionsbedingungen ausgetauscht. Die TemperaturabhĂ€ngigkeit dieser Zweiphasenreaktion darf jedoch auf keinen Fall mit dem experimentell ermittelten Plagioklas Thermometer verglichen werden.The article illustrates firstly, the extensive influence of the partial oxygen pressure on the solid solution relations in the system FeO-FeâOâ-CrâOâ may, in spite of a fixed Fe/Cr ratio, influence the formation of chromite phases in such a way, that they deviate appreciably from the fixed ratio.
Secondly, it is shown, that the hitherto experimentally investigated solid solutions in the pseudobinary system PbS-BiâSâ do not contribute towards the understanding of the genesis of the natural lead-bismuth sulfosalts, because of the presence of small amount of Cu, Fe, Ag and Sb which cannot be represented in this system.
Thirdly it is shown that, for the formation of metamorphic plagioclases, the temperature dependent solid solution compositions are not necessarily dependent on the total chemistry of the rock. In many examples it is possible to illustrate a relationship between the chemical composition of the plagioclase and the adjoining hornblende, in that the Ca-and Al-, Na-and Si-of these two phases are exchanged according to the prevailing physical-chemical reaction conditions. The temperature dependence of this two-phase reaction may, under no condition be compared to the experimentally determined plagioclase geothermometer.Cet article illustre premiĂšrement, l'influence marquante de la pression partielle d'oxygĂšne sur les domaines de solutions solides en systĂšme FeO-FeâOâ-CrâOâ. La pression partielle P[Oâ] rĂ©gnant dans un systĂšme de rapport Fe/Cr fixĂ© peut agir sur la formation des phases du type chromite, pour faire s'Ă©carter notablement leur composition de ce rapport.
DeuxiĂšmement, que les solutions solides jusqu'ici Ă©tudiĂ©es dans le systĂšme pseudobinaire PbS-BiâSâ ne contribuent pas Ă la comprĂ©hension de la genĂšse des sulfosels plomb-bismuth naturels en raison des faibles quantitĂ©s de Cu, Fe, Ag et Sb qui ne peuvent ĂȘtre reprĂ©sentĂ©s dans ce systĂšme.
TroisiĂšmement, on montre que la formation de plagioclases mĂ©tamorphiques dont la composition est fonction de la tempĂ©rature ne dĂ©pend pas nĂ©cessairement de la chimie de la roche totale. Dans de nombreux cas il est possible d'illustrer les relations entre les compositions des plagioclases et hornblendes coexistants. Le Ca, Al, Na et Si de ces deux phases s'Ă©changent d'aprĂšs les conditions physico-chimiques ambiantes. Les variations de tempĂ©rature de cette rĂ©action Ă deux phases ne peuvent en aucun cas ĂȘtre comparĂ©es au gĂ©othermomĂštre des plagioclases dĂ©terminĂ© expĂ©rimentalement.Klemm D. D., Snethlage R., Weber-Diefenbach K. Beispiele zum Einfluss der Bildungsbedingungen auf NatĂŒrliche Mischkristallgleichgewichte. In: Bulletin de la SociĂ©tĂ© française de MinĂ©ralogie et de Cristallographie, volume 97, 2-5, 1974. Les solutions solides en minĂ©ralogie. Colloque international du C.N.R.S. n° 234. 27-30 mai 1974, OrlĂ©ans, France
Die Kalksteinpanzer - stone armour - aus der Grabanlage des Quin Shihuang in Zusammenarbeit mit dem Museum of the Terracotta Warriors and Horses in Lintong Abschlussbericht zur Pilotstudie
SIGLEAvailable from TIB Hannover: F02B762 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman
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