Shaping the Rwenzoris: balancing uplift,erosion, and glaciation     

Georg Kaufmann  Matthias Hinderer  Douchko Romanov 《International Journal of Earth Sciences》2016,105(6):1761-1778

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Reactive ditches: A simple approach to implement denitrifying wood chip bioreactors to reduce nitrate exports into aquatic ecosystems?     

Matthias Pfannerstill  Insa Kühling  Cindy Hugenschmidt  Michael Trepel  Nicola Fohrer 《Environmental Earth Sciences》2016,75(13):1063

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Earth observation-based multi-scale impact assessment of internally displaced person (IDP) camps on wood resources in Zalingei,Darfur     

Kristin Spröhnle  Olaf Kranz  Elisabeth Schoepfer  Matthias Moeller  Stefan Voigt 《国际地球制图》2016,31(5):575-595

This study describes the development of a semi-automatic object-based image analysis approach for the detection and quantification of deforestation in Zalingei, Darfur, in consequence of the increasing concentration of refugees or internally displaced persons (IDPs) in the region. The classification workflow is based on a multi-scale approach, ranging from the analysis of high resolution SPOT-4 to very high resolution IKONOS and QuickBird satellite imagery between 2003 and 2008. The overall accuracy rates for the classification of the SPOT 4 data ranged from 92% up to 95%, while those for the QuickBird and IKONOS classification have shown values of 88 and 87%, respectively. The resulting trends in woody vegetation cover were compared with the development of the local population and the variability of precipitation. The results show that the strong increase in human population in the Zalingei IDP camps can be associated with considerable decrease in woody vegetation in the camp vicinity.  相似文献   

Performance of EVA-Based Membranes for SCL in Hard Rock     

Karl Gunnar Holter 《Rock Mechanics and Rock Engineering》2016,49(4):1329-1358

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Percentile indices for assessing changes in heavy precipitation events     

Christoph Schär  Nikolina Ban  Erich M. Fischer  Jan Rajczak  Jürg Schmidli  Christoph Frei  Filippo Giorgi  Thomas R. Karl  Elizabeth J. Kendon  Albert M. G. Klein Tank  Paul A. O’Gorman  Jana Sillmann  Xuebin Zhang  Francis W. Zwiers 《Climatic change》2016,137(1-2):201-216

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Impacts of regional climate change on air quality projections and associated uncertainties     

Gwendoline Lacressonnière  Gilles Foret  Matthias Beekmann  Guillaume Siour  Magnuz Engardt  Michael Gauss  Laura Watson  Camilla Andersson  Augustin Colette  Béatrice Josse  Virginie Marécal  Agnes Nyiri  Robert Vautard 《Climatic change》2016,136(2):309-324

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Low-frequency variability and CO2 transient climate change     

Gerald A Meehl  Warren M Washington  Thomas R Karl 《Climate Dynamics》1993,8(3):117-133

Results from a global coupled ocean-atmosphere general circulation model (GCM) are used to perform the first in a series of studies of the various time and space scales of climate anomalies in an environment of gradually increasing carbon dioxide (CO₂) (a linear transient increase of 1% per year in the coupled model). Since observed climate anomaly patterns often are computed as time-averaged differences between two periods, climate-change signals in the coupled model are defined using differences of various averaging intervals between the transient and control integrations. Annual mean surface air temperature differences for several regions show that the Northern Hemisphere warms faster than the Southern Hemisphere and that land areas warm faster than ocean. The high northern latitudes outside the North Atlantic contribute most to global warming but also exhibit great variability, while the high southern latitudes contribute the least. The equatorial tropics warm more slowly than the subtropics due to strong upwelling and mixing in the ocean. The globally averaged surface air temperature trend computed from annual mean differences for years 23–60 is 0.03 C per year. Projecting this trend to the time of CO₂ doubling in year 100 produces a warming of 2.3° C. By chance, one particular northern winter five-year average geographical difference pattern in the Northern Hemisphere from the coupled model resembles the recent observed pattern of surface temperature and sea-level pressure anomalies. This pattern is not consistent from one five-year period to the next in any season in the model. However, multidecadal averages in the coupled model show that the North Atlantic warms less than the rest of the high northern latitudes, and recent observations may be a manifestation of this phenomenon. Consistent geographic patterns of climate anomalies forced by increased CO₂ in the model are more evident with a longer averaging interval. There is also the possibility that the CO₂ climate-change signal may itself be a function of time and space. The general pattern of zonal mean temperature anomalies for all periods in the model shows warming in the troposphere and cooling in the stratosphere. This pattern (or one similar to it taking into account the rest of the trace gases) could be looked for in observations to verify the enhanced greenhouse effect. A zonal mean pattern, however, could prove scientifically satisfactory but of little value to policymakers seeking regional climate-change forecasts. These results from the coupled model underscore the difficulty in identifying a time- and space-dependent fingerprint of greenhouse warming that has some practical use from short climatic records and point to the need to understand the mechanisms of decadal-scale variability.The National Center for Atmospheric Research is sponsored by the National Science Foundation.  相似文献   

Experimental insight into spalling behavior of concrete tunnel linings under fire loading     

Matthias Zeiml  Roman Lackner  Herbert A. Mang 《Acta Geotechnica》2008,3(4):295-308

New experimental insight into the spalling behavior of concrete in fire conditions is presented in this paper. Spalling was recorded by a high-speed camera. The slow-motion sequences allow us to determine the size, shape, and velocity of the spalled-off pieces. With this information at hand, the released energy associated with every spalling event is computed and compared to the energies associated with pore-pressure and thermal-stress spalling. This comparison provides new insight into the impact of the various thermal, mechanical, and hydral processes controlling concrete spalling.  相似文献   

Integrating uncertainty: Canyon Creek hyperconcentrated flows of November 1989 and 1990   总被引：1，自引：0，他引：1  

Matthias Jakob  Hamish Weatherly 《Landslides》2008,5(1):83-95

Canyon Creek drains a 79 km² watershed in northwestern Washington State. Extensive logging occurred from the mid-1960s to 1980s, which resulted in numerous slope instabilities and a several order of magnitude increase in sediment supply to the creek. On November 9, 1989, a hyperconcentrated flow with a peak discharge of 450 m³/s destroyed one house on the fan. A forensic investigation of the event suggests that a temporary landslide dam may have formed at two coalescing earthflows about 4 km above the fan apex. The 1989 hyperconcentrated flow caused significant aggradation on the fan. One year later to the day, a significant flood occurred, which ran over the aggraded fan surface from the 1989 event. This latter event destroyed four more homes mostly through bank erosion and rendered a section of county road impassable. FLDWAV, a flood routing model capable of simulating unsteady flow conditions, was used to model landslide dam breaches for a number of different dam heights at the earthflows. Modeling results were then combined with historic air photograph interpretation, dendrochronology, and eyewitness accounts to construct a frequency–magnitude relationship for hyperconcentrated flows at Canyon Creek. FLDWAV results were combined with a hyperconcentrated flow runout model (FLO-2D) on the fan to estimate maximum flow depth and flow velocity for the design event, a 500-year return period with a predicted peak discharge of 710 m³/s. A large range of mitigation measures were reviewed, but it was concluded that buy-outs would be the most effective risk reduction measure. Property acquisition commenced in 2004.  相似文献   

Determination of shallow shear wave velocity profiles in the Cologne, Germany area using ambient vibrations   总被引：6，自引：1，他引：6  

Frank Scherbaum  Klaus-G. Hinzen  Matthias Ohrnberger 《Geophysical Journal International》2003,152(3):597-612

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