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Alexandrov G. A. Ginzburg A. S. Golitsyn G. S. 《Izvestiya Atmospheric and Oceanic Physics》2019,55(5):407-411
Izvestiya, Atmospheric and Oceanic Physics - The natural variability of regional climatic conditions poses certain difficulties in detecting global climate change at a local scale. The question... 相似文献
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Izvestiya, Atmospheric and Oceanic Physics - The minimum energy consumption in cities of the Russian Plain is largely determined by climatic conditions, because residential heating in winter is a... 相似文献
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Georgii A Alexandrov 《Carbon balance and management》2011,6(1):12
The International Year of Forests, declared by the UN, is a good occasion to discuss approaches to reducing forest degradation
in developing countries. The articles collected in Thematic Forest Series form a diversity of ideas which is essential for
setting the levels below which the countries' reduced emissions could be measured and credited. This editorial calls attention
to the use of Land-Use/Land-Cover Change models. 相似文献
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Vesselin A. Alexandrov 《Climatic change》1997,36(1-2):135-149
In recent years the problem of climate and its variations under the influence of natural processes and factors of anthropogenetic origin has come to the forefront of scientific and practical problems on a world-wide scale. Climate change vulnerability assessments of agronomic systems in Bulgaria have been initiated. In this paper preliminary results of this study are presented. Different climate change scenarios were defined. Global circulation model (GCM) scenarios and incremental scenarios for Bulgaria were created and applied. The influence of climate change on potential crop growing season above a base of 5° and 10 °C in Bulgaria was investigated. Increases in temperature can be expected to lengthen the potential growing season, resulting in a shift of thermal limits of agriculture in Bulgaria. The Decision Support System for Agrotechnology Transfer (DSSAT) Version 2.1 was used to assess the influence of climate change on grain yield of maize and winter wheat. Maize and winter wheat yields decreased with increasing temperatures and decreasing precipitation. 相似文献
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V. Alexandrov M. Schneider E. Koleva J.-M. Moisselin 《Theoretical and Applied Climatology》2004,79(3-4):133-149
Summary Climate data used for climate variability and change analyses, must be homogeneous, to be accurate. The data currently used in the Météo-France homogenization procedure, which does not require computation of regional reference series, was applied to precipitation and average air temperature series in Bulgaria. The Caussinus-Mestre method, with a double-step procedure, was used to detect multiple breaks and outliers in the long-term series of precipitation and average air temperature. A two factor linear model was applied for break correction. The homogenization procedure was run till all or most break risk was gone. Analysis of climate variability and change in Bulgaria during the 20th century was done on already homogenized precipitation and average air temperature series. The statistical significance of the trends obtained was evaluated by the coefficient of Spearman rank correlation. The variations of annual precipitation in Bulgaria showed an overall decrease. The country has experienced several drought episodes during the 20th century, most notably in the 1940s and 1980s. Seasonal precipitation in spring shows a positive trend at most weather stations across the country. The trend for summer and autumn precipitation is negative. A statistically significant increasing trend of winter precipitation in north Bulgaria was detected. No significant warming trend in the country was found during the last century inspite of the warming observed during the last two decades. Summer in Bulgaria tends to be warmer from the beginning of the 1980s. There is a statistically significant increasing trend of average air temperature during the winter season at the weather stations near the Danube river (north Bulgaria) during the periods 1901–2000 and 1931–2000. 相似文献
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Z.?Popova M.?Ivanova D.?Martins L.?S.?PereiraEmail author K.?Doneva V.?Alexandrov M.?Kercheva 《Natural Hazards》2014,74(2):865-886
Bulgarian agriculture is affected by droughts and, likely, by climate change. Thus, aiming at assessing its vulnerability, this study includes a general characterization of climate variability in eight selected locations, both in northern and southern Bulgaria. Trend tests were applied to monthly precipitation, maximum and minimum temperature and to the Standardized Precipitation Index with two-month time step (SPI-2) relative to the period of 1951–2004. Negative trends were identified for precipitation and SPI-2 at various locations, mainly in the Thrace Plain, indicating that dryness is likely to be increasing in Bulgaria. The vulnerability of rainfed maize systems to drought was studied using the previously calibrated WinISAREG model and the Stewart’s yield model to compute both the relative yield decrease (RYD) due to water stress and the corresponding net irrigation required to overcome those losses. Results identified a strong relation between SPI-2 for July–August (SPI-2July–Aug) and RYD. Results also show that yield losses are higher when the soils have a smaller soil water holding capacity. For the various regions under study, thresholds for RYD were defined considering the related economic impacts and the influence of soil characteristics on the vulnerability of the rainfed maize systems. Finally, to support drought risk management, SPI-2July–Aug thresholds were developed to be used as indicators of the economic risk of rainfed maize for various climate regions and soil groups in Bulgaria. 相似文献
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The authors review recent developments in the USSR in the use of remote sensing imagery in the analysis, at the world-regional and local levels, of major relief elements (and structural elements manifest in relief) typical of mountainous country. Keys to their interpretation at a variety of scales are described. Case studies and detailed interpretation of imagery in the Soviet Far East and Central Asia (large-scale) and the Caucasus (intermediate-scale) provide for the identification of all morphostructural elements possible through traditional analysis, and in the latter case, for the first direct detection of transverse (cross-cutting) faults. Translated from: Geomorfologiya, 1988, No. 1, pp. 16-29. 相似文献
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Oxygen isotope systematics of emerald: relevance for its origin and geological significance 总被引:2,自引:0,他引:2
G. Giuliani C. France-Lanord P. Coget D. Schwarz A. Cheilletz Y. Branquet D. Giard A. Martin-Izard P. Alexandrov D. H. Piat 《Mineralium Deposita》1998,33(5):513-519
Oxygen isotopic composition of emerald from 62 occurrences and deposits in the world reveals a wide range in δ18O (SMOW) between +6.2 and +24.7‰. The δ18O-values for each deposit are restricted and can be used to determine the origin of emerald from the world's most important
producers. The δ18O-value of emerald appears to be a fingerprint of its origin, especially for gems of exceptional quality from Colombia (eastern
emerald zone, δ18O = +16.8 ± 0.1‰; western emerald zone, δ18O = +21.2 ± 0.5‰), Afghanistan (δ18O = +13.5 ± 0.1‰), Pakistan (Swat-Mingora districts, δ18O = +15.7 ± 0.1‰), Brazil (Santa Terezinha de Goiás, δ18O = +12.2 ± 0.1‰; Quadrilatero Ferrifero, δ18O = +6.9 ± 0.4‰) and Zimbabwe (Sandawana, δ18O = +7.5 ± 0.5‰). Furthermore, the 18O-composition of emerald appears to be a good marker of its geological environment because the data suggest that host-rock-buffering
of fluid δ18O is considerable during fluid-rock interaction.
Received: 29 January 1998 / Accepted: 25 March 1998 相似文献