排序方式： 共有43条查询结果，搜索用时 18 毫秒
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Igri P. Moudi Tanessong Roméo S. Vondou D. A. Panda Jagabandhu Garba Adamou Mkankam F. Kamga Kamga A. 《Natural Hazards》2018,93(3):1565-1587
Natural Hazards - For numerical weather prediction over a particular region, it is important to know the best combination of physical parameterizations available in the considered modelling frame... 相似文献
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Roméo S. Tanessong P. Moudi Igri Derbetini A. Vondou P. H. Kamsu Tamo F. Mkankam Kamga 《Theoretical and Applied Climatology》2014,116(3-4):649-659
This paper examines the connection between the probability of precipitation and forecast amounts from Weather Research and Forecasting (WRF) model runs over Central and West Africa. A one season period (June–September 2010) was used to investigate the quantitative precipitation forecast–probability relationship. The predictive capability of this relationship was then tested on an independent sample of data (June–September 2011); 2010 and 2011 were wet and dry years, respectively. The results show that rainfall is less likely to occur in those areas where the model indicates no precipitation than it is elsewhere in the domain. Rainfall is more likely to occur in those regions where precipitation is predicted, especially where the predicted precipitation amounts are largest. The probabilities of rainfall forecasts based on this relationship are found to possess skill as measured by relative operating characteristic curves, reliability diagrams, and Brier skill scores. Skillful forecasts from the technique exist throughout 24-h periods for which WRF output was available. The results suggest that this forecasting tool might assist forecasters throughout the season in a wide variety of weather events and not only in areas of difficult-to-forecast convective systems. 相似文献
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Natural Hazards - This contribution highlights that the paper presented by Ma et al. (Nat Hazards 89(2):741–756, 2017) presents VIF lower than 1 which does not coincide with the natural... 相似文献
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Romée H. Kars Tony Reimann Christina Ankjærgaard Jakob Wallinga 《Boreas: An International Journal of Quaternary Research》2014,43(4):780-791
Post‐infrared (pIR) stimulated luminescence dating of sedimentary feldspar largely avoids the effects of anomalous fading that affect conventional infrared stimulated luminescence (IRSL) dating. However, optical resetting of pIR signals is more difficult than resetting the conventional IRSL signal, which may undermine the crucial assumption that pIR signals were effectively bleached upon deposition and burial of sediment grains. In this study, we quantify the bleaching properties of several pIR signals on various samples using laboratory‐simulated bleaching in full sunlight and water‐attenuated sunlight. Our data show that bleaching is most efficient under full spectrum conditions for all pIR signals and that pIR signals measured at elevated temperature are increasingly harder to bleach than IR and pIR signals measured at low temperature (e.g. IR at 50°C). All bleaching curves exhibit a very slow and steady decrease, indicating that a fixed un‐bleachable residual level cannot be reached within the 11 days of solar simulator exposure undertaken here. We show that the magnitude of a laboratory‐determined residual dose depends on the adopted bleaching protocol and cannot be used as a proxy for the dose that remains in the sample at the time of burial (remnant dose). Our data emphasize the importance of finding a balance between sufficient signal stability and a minimized contribution of a remnant dose when using pIR procedures for feldspar luminescence dating. 相似文献
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Emilio Rodríguez-Caballero José Raúl Román Sonia Chamizo Beatriz Roncero Ramos Yolanda Cantón 《地球表面变化过程与地形》2019,44(14):2771-2779
Biological soil crust, or biocrust communities, are the dominating life form in many extreme habitats, such as arid and semiarid badlands, where water scarcity and highly erodible substrates limit vegetation cover. While climate, soil and biotic factors have been described as environmental filters influencing biocrust distribution in such biomes, little is known about the effect of terrain attributes on creating specific microhabitats that promote or restrict biocrust colonization. This study aimed to identify the main terrain attributes controlling biocrust distribution in the driest badland system in Europe, the Tabernas Badlands (SE Spain). To do this, we analysed the influence of different terrain attributes related to landscape stability and microclimate formation on the spatial distribution of lichen and cyanobacteria, using field measurements and topographical information from a LiDAR survey. Our results showed that the spatial distribution of cyanobacteria-dominated biocrusts, which are physiologically and morphologically adapted to extreme drought and high UVA radiation, was mostly associated with areas of high potential incoming solar radiation. The exception was bare south-aspect hillslopes with very high sediment transport potential, where bare physically crusted soils were the dominant ground cover. Lichen-dominated biocrusts, in contrast, colonized near the top of north-aspect hillslopes, characterized by low potential incoming solar radiation and potential evapotranspiration, and their cover decreased downstream, as conditions became good enough for vascular plants. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd. 相似文献
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Esther Izquierdo-Llavall Teresa Román-Berdiel Antonio M. Casas Belén Oliva-Urcia Inmaculada Gil-Pe?a Ruth Soto Antonio Jabaloy 《International Journal of Earth Sciences》2012,101(7):1817-1834
The present study provides new magnetic and microstructural data for the Eaux-Chaudes granodioritic massif (Western Axial Zone, Pyrenees) and contributes to the understanding of its geometry, internal structure and emplacement mechanism. Moreover, the geological cross-sections and field data allow to reconstruct the evolution of the whole area from Variscan to Alpine times and to integrate the emplacement of the igneous body in the context of the Variscan orogeny. The Eaux-Chaudes pluton (301?±?9?Ma) is mainly composed by granodiorite, describing a normal compositional zoning and an approximately concentric arrangement that is consistent with the zonation of the low-field magnetic susceptibility. Magnetic foliation is subhorizontal in the inner part of the intrusion and becomes parallel to the petrographical contacts along pluton margins, roughly describing the geometry of the intrusion. Magnetic lineations are dominantly subhorizontal, with E–W to ENE–WSW directional maximum. The general parallelism between Variscan structures of the host rock and the geometry and magmatic fabric of the intrusion reveals a late syn-Variscan emplacement. The tectonic regime registered during magma emplacement is in agreement with an N–S shortening and an E–W stretching direction, consistent with the transpressive regime deduced for other Pyrenean intrusions. Alpine overprint produced a slight tilting in the southern part of the intrusion, but it can be considered that the original Variscan structure is basically unchanged. 相似文献
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Natural Hazards - This article constitutes an effort towards providing an academic overview and grounding for the concept of capacities in the context of disaster studies and disaster risk... 相似文献
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Andrea Román-Sánchez Tony Reimann Jakob Wallinga Tom Vanwalleghem 《地球表面变化过程与地形》2019,44(10):2051-2065
The interplay of bioturbation, soil production and long-term erosion–deposition in soil and landscape co-evolution is poorly understood. Single-grain post-infrared infrared stimulated luminescence (post-IR IRSL) measurements on sand-sized grains of feldspar from the soil matrix can provide direct information on all three processes. To explore the potential of this novel method, we propose a conceptual model of how post-IR IRSL-derived burial age and fraction of surface-visiting grains change with soil depth and along a hillslope catena. We then tested this conceptual model by comparison with post-IR IRSL results for 15 samples taken at different depths within four soil profiles along a hillslope catena in the Santa Clotilde Critical Zone Observatory (southern Spain). In our work, we observed clear differences in apparent post-IR IRSL burial age distributions with depth along the catena, with younger ages and more linear age–depth structure for the hill-base profile, indicating the influence of lateral deposition processes. We noted shallower soils and truncated burial age–depth functions for the two erosional mid-slope profiles, and an exponential decline of burial age with depth for the hill-top profile. We suggest that the downslope increase in the fraction of surface-visiting grains at intermediate depths (20 cm) indicates creep to be the dominant erosion process. Our study demonstrates that single-grain feldspar luminescence signature-depth profiles provide a new way of tracing vertical and lateral soil mixing and transport processes. In addition, we propose a new objective luminescence-based criterion for mapping the soil-bedrock boundary, thus producing soil depths in better agreement with geomorphological process considerations. Our work highlights the possibilities of feldspar single grain techniques to provide quantitative insights into soil production, bioturbation and erosion–deposition. © 2019 The Authors. Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd. 相似文献