长江三峡库区地质灾害遥感图像信息处理及其监测和评估   总被引：13，自引：0，他引：13  

杨武年  濮国梁  CAUNEAU F  RANCHIN T  PARIS J P 《地质学报》2005,79(3):423-430

长江三峡作为世界上最大的水利工程,引起了世界的广泛关注。水库堤岸的长度、水库容载力、三峡移民数量以及其对生态环境的影响都成为议论的焦点。最引人注目的是长江两岸存在大量的地质灾害,如：滑坡、崩塌等,其中有些大型灾害体目前仍处于活动状态,这将给三峡工程的安全与库岸稳定性以及库区生态环境带来深远的影响。因此,采用3S和多时相TM、SPOT、ERS—SAR和RADARSAT等图像集成新技术来快速有效地监测、研究和评估地质灾害对三峡工程以及周边环境的影响,为地质灾害的预防和治理提供科学依据,本成果具有重要的学术意义和实用价值。  相似文献   

A recent build-up of atmospheric CO₂ over Europe. Part 1: observed signals and possible explanations     

By MICHEL RAMONET  PHILIPPE CIAIS  TUULA AALTO  CÉLINE AULAGNIER  FRÉDÉRIC CHEVALLIER  DOMENICO CIPRIANO  THOMAS J. CONWAY  LASZLO HASZPRA  VICTOR KAZAN  FRANK MEINHARDT  JEAN-DANIEL PARIS  MARTINA SCHMIDT  PETER SIMMONDS  IRÈNE XUEREF-RÉMY  JAROSLAW N. NECKI 《Tellus. Series B, Chemical and physical meteorology》2010,62(1):1-13

We analysed interannual and decadal changes in the atmospheric CO₂ concentration gradient (ΔCO₂) between Europe and the Atlantic Ocean over the period 1995–2007. Fourteen measurement stations are used, with Mace-Head being used to define background conditions. The variability of ΔCO₂ reflects fossil fuel emissions and natural sinks activity over Europe, as well as atmospheric transport variability. The mean ΔCO₂ increased by 1–2 ppm at Eastern European stations (∼30% growth), between 1990–1995 and 2000–2005. This built up of CO₂ over the continent is predominantly a winter signal. If the observed increase of ΔCO₂ is explained by changes in ecosystem fluxes, a loss of about 0.46 Pg C per year would be required during 2000–2005. Even if severe droughts have impacted Western Europe in 2003 and 2005, a sustained CO₂ loss of that magnitude is unlikely to be true. We sought alternative explanations for the observed CO₂ build-up into transport changes and into regional redistribution of fossil fuel CO₂ emissions. Boundary layer heights becoming shallower can only explain 32% of the variance of the signal. Regional changes of emissions may explain up to 27% of the build-up. More insights are given in the Aulagnier et al. companion paper.  相似文献   

Chitinozoans from the Fenxiang Formation (Early Ordovician) of Yichang, Hubei Province, China     

CHEN Xiaohong  Florentin PARIS  ZHANG Miao 《《地质学报》英文版》2008,82(2):287-294

Chitinozoans collected from upper Tremadocian to lower Floian strata of Chenjiahe section, Yichang, western Hubei, China comprise six species belonging respectively to the genera Euconochitina including a new species, Euconochitina fenxiangensis, Lagenochitina and Bursachitina, together with Desmochitina sp. and Eremochitina sp. The chitinozoan succession across the interval is correlated with relevant conodont and chitinozoan biozones and two new regional chitinozoan biozones, the Lagenochitina destombesi Biozone and the Euconochitina symmetrica Biozone are proposed based on their stratigraphic ranges in the Fenxiang to Honghuayuan formations in the Chenjiahe section.  相似文献   

The YAK-AEROSIB transcontinental aircraft campaigns: new insights on the transport of CO₂, CO and O₃ across Siberia     

J.-D. PARIS  P. CIAIS  P. NÉDÉLEC  M. RAMONET  B. D. BELAN  M. YU. ARSHINOV  G. S. GOLITSYN  I. GRANBERG  A. STOHL  G. CAYEZ  G. ATHIER  F. BOUMARD  J.-M. COUSIN 《Tellus. Series B, Chemical and physical meteorology》2008,60(4):551-568

Two airborne campaigns were carried out to measure the tropospheric concentrations and variability of CO₂, CO and O₃ over Siberia. In order to quantify the influence of remote and regional natural and anthropogenic sources, we analysed a total of 52 vertical profiles of these species collected in April and September 2006, every ∼200 km and up to 7 km altitude. CO₂ and CO concentrations were high in April 2006 (respectively 385–390 ppm CO₂ and 160–200 ppb CO) compared to background values. CO concentrations up to 220 ppb were recorded above 3.5 km over eastern Siberia, with enhancements in 500–1000 m thick layers. The presence of CO enriched air masses resulted from a quick frontal uplift of a polluted air mass exposed to northern China anthropogenic emissions and to fire emissions in northern Mongolia. A dominant Asian origin for CO above 4 km (71.0%) contrasted with a dominant European origin below this altitude (70.9%) was deduced both from a transport model analysis, and from the contrasted ΔCO/ΔCO₂ ratio vertical distribution. In September 2006, a significant O₃ depletion (∼–30 ppb) was repeatedly observed in the boundary layer, as diagnosed from virtual potential temperature profiles and CO₂ gradients, compared to the free troposphere aloft, suggestive of a strong O₃ deposition over Siberian forests.  相似文献   

Yellow impact glass from the K/T boundary at Beloc (Haiti): XANES determination of the Fe oxidation state and implications for formation conditions     

Gabriele GIULI  Sigrid Griet EECKHOUT  Christian KOEBERL  Giovanni PRATESI  Eleonora PARIS 《Meteoritics & planetary science》2008,43(5):981-986

Abstract— We determined the iron oxidation state and coordination number in five samples of yellow impact glass from the Cretaceous‐Tertiary (K/T) boundary section at Beloc, Haiti, which formed as the result of impact melting during the Chicxulub impact event. The samples were analyzed by Fe K‐edge XANES spectroscopy and the results were compared with published data on eight black impact glasses and one high Si‐K impact spherule from the same impact layer. The pre‐edge peak of our high‐resolution XANES spectra displays evident variations indicative of significant changes in the Fe oxidation state, spanning a wide range from about 75 to 100 mole% Fe³⁺. Yellow K/T glasses have significantly higher Fe³⁺/(Fe²⁺ + Fe³⁺) ratios compared to black K/T impact glasses (from 20 to 75 mole% Fe³⁺) and high Si‐K glass (20 mole% Fe³⁺). In particular, all the pre‐edge peak data on these three types of impact glasses plot between two mixing lines joining a point calculated as the mean of a group of tektites studied so far (consisting of ^[4]Fe²⁺ and ^[5]Fe²⁺) to ^[4]Fe³⁺ and ^[5]Fe³⁺, respectively. Thus, the XANES spectra of the yellow K/T glasses can be interpreted as a mixture of ^[4]Fe^{2+, [5]}Fe^{2+, [4]}Fe³⁺, and ^[5]Fe³⁺. Our observations can be explained by a very large range of oxygen fugacity conditions during melt formation. Furthermore, there is a clear positive relationship between the Fe³⁺/(Fe²⁺ + Fe³⁺) ratio and the Ca content of these glasses, suggesting that the Fe oxidation state was influenced by the relative contribution of Ca‐sulfate‐ and Ca‐carbonate‐bearing sedimentary rocks at the impact site.  相似文献