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91.
Flooding on the German Rhine during the 20th century was tested for trends and assessed to identify causal mechanisms driving worsening of flooding. A review of previous research outlines the range of impacts due to climate change, land‐use shifts, and river regulation. Analysis of hydrologic data, especially of the long record at Cologne, documents statistically significant increases in both flood magnitudes and frequencies. Specific‐gauge analysis, which isolates the effects of channel modification, documents that 20th century river engineering has caused little of the observed increase in flooding on the German Rhine. Precipitation records from the Rhine basin confirm that flood magnification has been driven by upstream factors, including an increase in flood‐producing precipitation of roughly 25% during the past 100 years and increases in runoff yields. In addition, agricultural land‐use records suggest that flood magnification can be partially explained by 20th century trends documenting intensification and industrialization of German agriculture. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
92.
William S. Burgett Michael M. Vick David S. Davis Matthew Colless Roberto De Propris Ivan Baldry Carlton Baugh Joss Bland-Hawthorn Terry Bridges Russell Cannon Shaun Cole Chris Collins Warrick Couch Nicholas Cross Gavin Dalton Simon Driver George Efstathiou Richard Ellis Carlos S. Frenk Karl Glazebrook Edward Hawkins Carole Jackson Ofer Lahav Ian Lewis Stuart Lumsden Steve Maddox Darren Madgwick Peder Norberg John A. Peacock Will Percival Bruce Peterson Will Sutherland Keith Taylor 《Monthly notices of the Royal Astronomical Society》2004,352(2):605-654
93.
94.
Nicholas J. Cox 《The Professional geographer》1980,32(1):51-54
Hitch-hiking has been ignored by traditional geography. In this article it is shown that ideas and techniques from the new geography yield substantial insights into its character as a spatial process. 相似文献
95.
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97.
Ilhem Bentaleb Cyril Langlois Céline Martin Paula Iacumin Matthieu Carré Pierre-Olivier Antoine Francis Duranthon Issam Moussa Jean-Jacques Jaeger Nicholas Barrett Ron Kandorp 《Comptes Rendus Geoscience》2006,338(3):172-179
The relationship between the oxygen isotope ratio of mammal tooth enamel and that of drinking water was used to reconstruct changes in the Miocene oxygen isotope ratio of rainfall (meteoric water OMW). These, in turn, are related to climatic parameters (temperature, precipitation and evaporation rate). O values of rhinocerotid teeth from the Aquitaine Basin (southwestern France) suggest a significant climatic change between 17 and 12 Ma, characterized by cooling together with precipitation increase, in agreement with other terrestrial and oceanic records. To cite this article: I. Bentaleb et al., C. R. Geoscience 338 (2006). 相似文献
98.
99.
Emilie Vanvyve Nicholas Hall Christophe Messager Stéphanie Leroux Jean-Pascal van Ypersele 《Climate Dynamics》2008,30(2-3):191-202
Sensitivity studies with regional climate models are often performed on the basis of a few simulations for which the difference
is analysed and the statistical significance is often taken for granted. In this study we present some simple measures of
the confidence limits for these types of experiments by analysing the internal variability of a regional climate model run
over West Africa. Two 1-year long simulations, differing only in their initial conditions, are compared. The difference between
the two runs gives a measure of the internal variability of the model and an indication of which timescales are reliable for
analysis. The results are analysed for a range of timescales and spatial scales, and quantitative measures of the confidence
limits for regional model simulations are diagnosed for a selection of study areas for rainfall, low level temperature and
wind. As the averaging period or spatial scale is increased, the signal due to internal variability gets smaller and confidence
in the simulations increases. This occurs more rapidly for variations in precipitation, which appear essentially random, than
for dynamical variables, which show some organisation on larger scales. 相似文献
100.
Anthony J. Smith Jon Loveday Nicholas J. G. Cross 《Monthly notices of the Royal Astronomical Society》2009,397(2):868-882
We present luminosity and surface-brightness distributions of 40 111 galaxies with K -band photometry from the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS), Data Release 3 and optical photometry from Data Release 5 of the Sloan Digital Sky Survey (SDSS). Various features and limitations of the new UKIDSS data are examined, such as a problem affecting Petrosian magnitudes of extended sources. Selection limits in K - and r -band magnitude, K -band surface brightness and K -band radius are included explicitly in the 1/ V max estimate of the space density and luminosity function. The bivariate brightness distribution in K -band absolute magnitude and surface brightness is presented and found to display a clear luminosity–surface brightness correlation that flattens at high luminosity and broadens at low luminosity, consistent with similar analyses at optical wavelengths. Best-fitting Schechter function parameters for the K -band luminosity function are found to be M *− 5 log h =−23.19 ± 0.04, α=−0.81 ± 0.04 and φ*= (0.0166 ± 0.0008) h 3 Mpc−3 , although the Schechter function provides a poor fit to the data at high and low luminosity, while the luminosity density in the K band is found to be j = (6.305 ± 0.067) × 108 L⊙ h Mpc−3 . However, we caution that there are various known sources of incompleteness and uncertainty in our results. Using mass-to-light ratios determined from the optical colours, we estimate the stellar mass function, finding good agreement with previous results. Possible improvements are discussed that could be implemented when extending this analysis to the full LAS. 相似文献