Towards a better understanding of the evolution of the flood risk in Mediterranean urban areas: the case of Barcelona     

Cort&#;s  Maria  Llasat  Maria Carmen  Gilabert  Joan  Llasat-Botija  Montserrat  Turco  Marco  Marcos  Ra&#;l  Mart&#;n Vide  Juan Pedro  Falc&#;n  Llu&#;s 《Natural Hazards》2017,85(1):39-57

Dam failure constitutes a grave threat to human life. However, there is still a lack of systematic and comprehensive research on the loss of life (L) caused by dam break in China. From the perspective of protecting human life, a new calculation method for L occurred in dam break floods is put forward. Fourteen dam failure cases in China are selected as the basic data by three-dimensional stratified sampling, balancing spatial, vertical elevation and temporal representations, as well as considering various conditions of the dam collapse. The method includes three progressive steps: Firstly, some impact factors of loss of life (IFL) are selected by literature survey, i.e., severity of dam break flood (S _F), population at risk (P _R), understanding of dam break (U _B), warning time (T _W) and evacuation condition (E _C). And the other IFL of weather during dam break (W _B), dam break mode (M _B), water storage (S _W), building vulnerability (V _B), dam break time (T _B) and average distance from affected area to dam (D _D) are also taken into account to get a more comprehensive consideration. According to disaster system and disaster risk, these eleven IFL are divided into four categories. Through the improved entropy method, eight key IFL are further selected out of the eleven. Secondly, four L modules are built based on four categories, which are L-causing factor module (M ₁), L-prone environment module (M ₂), affected body module (M ₃) and rescue condition module (M ₄). Eventually, by using two methods of multivariate nonlinear regression and leave-one-out cross-validation in combination with coupled four modules, the calculation method for L is established. Compared with the results of Graham method and D&M method, the result of the proposed one is much closer to the actual value and performs better in fitting effect and regional applicability. In the application, L calculation and consequence assessment are carried out in the example of Hengjiang reservoir that has already broken down. At the same time, L calculation and risk prediction are used in the analysis of Yunshan reservoir, which is under planning. The proposed method can not only be applied to estimate L and its rate (f _L ) under various types of dam break conditions in China, but also provide a reliable consequence assessment and prediction approach to reduce the risk of L.  相似文献   

U-Pb geochronology on zircon and columbite-group minerals of the Cap de Creus pegmatites,NE Spain     

Van Lichtervelde  Marieke  Grand’Homme  Alexis  de Saint-Blanquat  Michel  Olivier  Philippe  Gerdes  Axel  Paquette  Jean-Louis  Melgarejo  Joan Carles  Druguet  Elena  Alfonso  Pura 《Mineralogy and Petrology》2017,111(1):1-21

Mineralogy and Petrology - The Cap de Creus granitic pegmatites in the eastern Catalan Pyrenees were dated using in situ U-Pb geochronology by laser ablation ICP-MS on zircon and columbite-group...  相似文献   

A High-Speed Erupting-Prominence CME: A Bridge Between Types     

Feynman  Joan  Ruzmaikin  Alexander 《Solar physics》2004,219(2):301-313

Solar Physics - Several studies have indicated that there may be two distinct types of coronal mass ejections (CMEs); a high-velocity bright energetic type associated with flares, and a smaller...  相似文献   

Trace/minor element:calcium ratios in cultured benthic foraminifera. Part II: Ontogenetic variation     

Christopher J. Hintz  Timothy J. Shaw  Joan M. Bernhard  G. Thomas Chandler  Daniel C. McCorkle 《Geochimica et cosmochimica acta》2006,70(8):1964-1976

Ontogenetic (developmental stage) measurements of Mg/Ca and Sr/Ca were made on the benthic foraminifer Bulimina aculeata, which were cultured under controlled physicochemical conditions of temperature, pH, alkalinity, salinity, and trace- and minor-element concentrations. We utilized two methods of ontogenetic sampling—whole specimens progressively increasing in length and laser microdissection of a single specimen with subsequent analysis of dissected portions. A novel high-resolution laser-microdissection (HRLM) method allowed for precise (10 μm) cuts of the foraminiferal tests (shells) along the geometrically complex sutures distinguishing individual chambers. This new microdissection method limited sample loss and cross-contamination between foraminiferal chambers. Little or no variation in D_Sr was observed at different foraminiferal developmental stages. Conversely, D_Mg was enriched during a mid-developmental stage of whole-specimen samples (150-225 μm D_Mg = 1.6 × 10⁻³) compared to earlier and later stages (<150 μm, >225 μm D_Mg = 8.3 × 10⁻⁴). Further analysis of HRLM ontogenetic samples showed a larger, age-dependent D_Mg signature variation. This increase in shell Mg/Ca may contribute substantially to the measured inter-individual variability in Mg/Ca temperature prediction for cultured B. aculeata. Due to relatively large Mg/Ca inter- and intra-individual variability, measuring similar-size foraminiferal samples may improve the precision of paleotemperature prediction. Additionally, partial dissolution of the highest ontogenetically Mg-enriched calcite (D_Mg = 1.3 × 10⁻²-1.6 × 10⁻²) may occur in undersaturated bottom-water environments or during reductive cleaning procedures. Thus, the calcite phases remaining after partial dissolution by either natural or laboratory cleaning processes may not accurately represent the calcification environment.  相似文献   

Two‐hourly surface change on supra‐tidal rock (Marengo,Victoria, Australia)     

Lluís Gómez‐Pujol  Wayne J. Stephenson  Joan J. Fornós 《地球表面变化过程与地形》2007,32(1):1-12

A traversing micro‐erosion meter was used to measure rock surface micro‐topography over 40 cm² on a supra‐tidal cliff face from early morning to late evening in late spring. From 06:00 hours to 22:00 hours the relative heights of 188 coordinates were obtained using the meter at 2‐hour intervals, resulting in a data set of 1607 readings. Monitoring shows that rock surfaces are dynamic entities, with significant rise and fall relative to the first measurement at shorter timescales than previously reported. The maximum positive rise between readings was 0·261 mm and lowering was 0·126 mm. The pattern of change did not relate as expected to environmental variables such as temperature or insolation. Rather, the surface showed greater surface change in the early morning and late afternoon. It is hypothesized that this pattern relates to the expansion and contraction of lichen thalli as moisture is absorbed during higher humidity in the morning and late afternoon. The implications of these results for weathering studies are considered. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Hydrogen Peroxide at the Bermuda Atlantic Time Series Station. Part 1: Temporal Variability of Atmospheric Hydrogen Peroxide and Its Influence on Seawater Concentrations     

Robert J. Kieber  William J. Cooper  Joan D. Willey  G. Brooks Avery Jr. 《Journal of Atmospheric Chemistry》2001,39(1):1-13

Diurnal and seasonal variations in atmospheric hydrogen peroxideconcentrations wereinvestigated during a summer and winter cruise aboard the R.V. `Endeavor' atthe BermudaAtlantic Time Series Station. Rainwater peroxide concentrations in Augustdisplayed dielvariability while no temporal H₂O₂ pattern was evidentin March rain. Averageconcentrations in March were also significantly lower than August whichindicates photochemicalprocesses are involved in controlling hydrogen peroxide concentrations inmarine rainwaterfalling over the open ocean. The range of gas phase hydrogen peroxideconcentrations wasbetween 1 and 6 ppbv and also exhibited a strong diurnal pattern during bothAugust and Marchwith concentration maxima in the early evening. The influence of atmosphericdeposition onsurface seawater hydrogen peroxide levels was also evaluated. Hydrogenperoxide depth profileswere measured on four separate occasions before and after rain events duringthe Augustsampling period. The input of rainfall hydrogen peroxide was observedthroughout the 25 metermixed layer with surface concentrations two fold larger in the morning aftera rain event. Theintegrated increase in hydrogen peroxide after the rain from 0 to 90 meterswas 1,720 molalmost all of which could be accounted for by the peroxide added from rain.The data presentedin this study represent the first detailed, simultaneous measurements ofhydrogen peroxide inmarine air, rain and surface seawater.  相似文献   

Towards a better understanding of the evolution of the flood risk in Mediterranean urban areas: the case of Barcelona     

Maria Cortès  Maria Carmen Llasat  Joan Gilabert  Montserrat Llasat-Botija  Marco Turco  Raül Marcos  Juan Pedro Martín Vide  Lluís Falcón 《Natural Hazards》2018,93(1):39-60

This contribution explores the evolution of the flood risk in the Metropolitan Area of Barcelona (MAB; Northeast Spain) from 1981 to 2015, and how it has been affected by changes in land use, population and precipitation. To complete this study, we analysed PRESSGAMA and INUNGAMA databases to look for all the information related to the floods and flash floods that have affected the chosen region. The “Consorcio de Compensación de Seguros”, a state insurance company for extraordinary risks, provided data on economic damage. The extreme precipitation trend was analysed by the Fabra Observatory and El Prat-Airport Observatory, and daily precipitation data were provided by the State Meteorological Agency of Spain (AEMET) and the Meteorological Service of Catalonia (SMC). Population data were obtained from the Statistical Institute of Catalonia (IDESCAT). Changes in land use were estimated from the land use maps for Catalonia corresponding to 1956, 1993, 2000, 2005 and 2009. Prevention measures like rainwater tanks and improvements to the drainage system were also been considered. The specific case of Barcelona is presented, a city recognised by United Nations International Strategy for Disaster Reduction as a model city for urban resilience to floods. The evolution of flood events in the MAB does not show any significant trend for this period. We argue that the evolution in floods can be explained, at least in part, by the lack of trend in extreme precipitation indices, and also by the improvements in flood prevention measures.  相似文献   

Evaluation of morphometry-based dating of monogenetic volcanoes—a case study from Bandas del Sur, Tenerife (Canary Islands)     

Gábor Kereszturi  Adelina Geyer  Joan Martí  Károly Németh  F. Javier Dóniz-Páez 《Bulletin of Volcanology》2013,75(7):1-19

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Tectono-stratigraphic evolution of an inverted extensional basin: the Cameros Basin (north of Spain)     

Silvia Omodeo Salè  Joan Guimerà  Ramón Mas  José Arribas 《International Journal of Earth Sciences》2014,103(6):1597-1620

The Cameros Basin is a part of the Mesozoic Iberian Rift. It is an extensional basin formed during the late Jurassic and early Cretaceous, in the Mesozoic Iberian Rift context, and it was inverted in the Cenozoic as a result of the Alpine contraction. This work aims to reconstruct the tectono-stratigraphic evolution of the basin during the Mesozoic, using new and revised field, geophysical and subsurface data. The construction of a basin-wide balanced section with partial restorations herein offers new insights into the geometry of the syn-rift deposits. Field data, seismic lines and oil well data were used to identify the main structures of the basin and the basin-forming mechanisms. Mapping and cross-sectional data indicate the marked thickness variation of the depositional sequences across the basin, suggesting that the extension of the depositional area varied during the syn-rift stage and that the depocentres migrated towards the north. From field observation and seismic line interpretation, an onlap of the depositional sequences to the north, over the marine Jurassic substratum, can be deduced. In the last few decades, the structure and geometry of the basin have been strongly debated. The structure and geometry of the basin infill reconstructed herein strongly support the interpretation of the Cameros Basin as an extensional-ramp synclinal basin formed on a blind south-dipping extensional ramp. The gradual hanging-wall displacement to the south shifted the depocentres to the north over time, thus increasing the basin in size northwards, with onlap geometry on the pre-rift substratum. The basin was inverted by means of a main thrust located in a detachment located in the Upper Triassic beds (Keuper), which branched in depth with the Mesozoic extensional fault flat. The reconstruction of the tectono-stratigraphic evolution of the Cameros Basin proposed herein represents a synthesis and an integration of previous studies of the structure and geometry of the basin. This study can be used as the basis for future basin-scale research and for modelling the ancient petroleum system of the basin.  相似文献   

Provenance-related characteristics of beach sediments around the island of Menorca, Balearic Islands (western Mediterranean)     

Lluís Gómez-Pujol  Francesc X. Roig-Munar  Joan J. Fornós  Pau Balaguer  Jaume Mateu 《Geo-Marine Letters》2013,33(2-3):195-208

The island of Menorca, one of the Balearic Islands (Spain) located in the western Mediterranean, is characterised by a contrasting geology and landscape with two major geographic domains: (1) a southern region called Migjorn, comprised of Late Miocene calcarenites and limestones, and (2) a northern region known as Tramuntana, which is composed of folded and faulted Palaeozoic, Mesozoic and Tertiary (Oligocene) siliceous and calcareous rocks. Both domains are lined by numerous pocket beaches exhibiting a high variety of surficial sediment assemblages. Grain-size and compositional analyses revealed that cliff erosion and nearshore Posidonia oceanica meadows are the main sources of sediments consisting mostly of medium- to coarse-grained carbonate sands of marine biogenic origin, with variable amounts of terrigenous rock fragments and quartz. Based on distinctly different contributions of bioclastic material, biogenic carbonates and quartz, 320 sediment samples from 64 beaches were grouped into different facies associations dominated by either (1) biogenic sands, (2) biogenic sands with terrigenous contributions or (3) terrigenous sands with quartz. Nevertheless, there is a marked regional variability in sediment texture and composition. Thus, variable mixtures of carbonate and siliciclastic sediments characterise the beaches of the northern region, whereas the beaches of the southern region are composed mostly of carbonate sands of marine biogenic origin. An exception is the central sector of the south coast, which is enriched in quartz sand (~10 %); this can be related to outcrops of quartz-rich basement rock and also to rocks exposed in some northern drainage basins captured by southern streams since the Plio-Quaternary.  相似文献