Stellar sources of dust in the high-redshift Universe     

Rosa Valiante  Raffaella Schneider  Simone Bianchi  Anja C. Andersen 《Monthly notices of the Royal Astronomical Society》2009,397(3):1661-1671

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On the peculiar properties of the narrow-line quasar PG 1543+489     

Cristian Vignali  Enrico Piconcelli  Stefano Bianchi  Giovanni Miniutti 《Monthly notices of the Royal Astronomical Society》2008,388(2):761-769

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Advances in pan‐European flood hazard mapping          下载免费PDF全文

Lorenzo Alfieri  Peter Salamon  Alessandra Bianchi  Jeffrey Neal  Paul Bates  Luc Feyen 《水文研究》2014,28(13):4067-4077

Flood hazard maps at trans‐national scale have potential for a large number of applications ranging from climate change studies, reinsurance products, aid to emergency operations for major flood crisis, among others. However, at continental scales, only few products are available, due to the difficulty of retrieving large consistent data sets. Moreover, these are produced at relatively coarse grid resolution, which limits their applications to qualitative assessments. At finer resolution, maps are often limited to country boundaries, due to limited data sharing at trans‐national level. The creation of a European flood hazard map would currently imply a collection of scattered regional maps, often lacking mutual consistency due to the variety of adopted approaches and quality of the underlying input data. In this work, we derive a pan‐European flood hazard map at 100 m resolution. The proposed approach is based on expanding a literature cascade model through a physically based approach. A combination of distributed hydrological and hydraulic models was set up for the European domain. Then, an observed meteorological data set is used to derive a long‐term streamflow simulation and subsequently coherent design flood hydrographs for a return period of 100 years along the pan‐European river network. Flood hydrographs are used to simulate areas at risk of flooding and output maps are merged into a pan‐European flood hazard map. The quality of this map is evaluated for selected areas in Germany and United Kingdom against national/regional hazard maps. Despite inherent limitations and model resolution issues, simulated maps are in good agreement with reference maps (hit rate between 59% and 78%, critical success index between 43% and 65%), suggesting strong potential for a number of applications at the European scale. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Early Jurassic palaeoenvironments in the Surat Basin,Australia – marine incursion into eastern Gondwana     

Andrew D. La Croix  Jianhua He  Valeria Bianchi  Jiahao Wang  Sebastian Gonzalez  Jim R. Undershultz 《Sedimentology》2020,67(1):457-485

Interpretations of palaeodepositional environments are important for reconstructing Earth history. Only a few maps showing the Jurassic depositional environments in eastern Australia currently exist. Consequently, a detailed understanding of the setting of Australia in Gondwana is lacking. Core, wireline logs, two-dimensional and three-dimensional seismic from the Precipice Sandstone and Evergreen Formation in the Surat Basin have been used to construct maps showing the evolution of depositional environments through the Early Jurassic. The results indicate the succession consists of three third-order sequences (Sequence 1 to Sequence 3) that were controlled by eustatic sea level. The lowstand systems tract in Sequence 1 comprises braidplain deposits, confined to a fairway that parallels the basin centre. The strata were initially deposited in two sub-basins, with rivers flowing in different orientations in each sub-basin. The transgressive systems tract of Sequence 1 to lowstand systems tract of Sequence 3 is dominated by fluvio–deltaic systems infilling a single merged basin centre. Finally, the transgressive and highstand systems tracts of Sequence 3 show nearshore environments depositing sediment into a shallow marine basin. In the youngest part of this interval, ironstone shoals are the most conspicuous facies, the thickness and number of which increase towards the north and east. This study interprets a corridor to the open ocean through the Clarence–Moreton Basin, or the Carpentaria and Papuan basins, evidence of which has been eroded. These results challenge a commonly held view that eastern Australia was not influenced by eustasy, and propose a more dynamic palaeogeographic setting comprising a mixture of fluvial, deltaic and shallow marine sedimentary environments. This work can be used to unravel the stratigraphic relationships between Mesozoic eastern Australian basins, or in other basins globally as an analogue for understanding the complex interplay of paralic depositional systems in data poor areas.  相似文献   

DISOLV: A Python Package for the Interpretation of Borehole Dilution Tests     

Sarah L. Collins  Marco Bianchi 《Ground water》2020,58(5):805-812

Single borehole dilution tests (SBDTs) are an inexpensive but effective technique for hydrogeological characterization of hard-rock aquifers. We present a freely available, easy-to-use, open-source Python package, DISOLV, for plotting, analyzing, and modeling SBDT data. DISOLV can significantly reduce the time spent interpreting field data by helping to identify flowing fractures intersecting the borehole and estimate the corresponding flow rates. DISOLV is successfully benchmarked against two analytical solutions. We also present an example application to real data collected in a borehole in a crystalline basement aquifer in southern India.  相似文献   

Estimation of the Crustal Bulk Properties Beneath Mainland Portugal from P-Wave Teleseismic Receiver Functions     

Süleyman Dündar  Nuno A. Dias  Graça Silveira  Rainer Kind  Lev Vinnik  Luís Matias  Marcelo Bianchi 《Pure and Applied Geophysics》2016,173(6):1949-1970

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Towards a predictive model to assess the natural position of the Posidonia oceanica seagrass meadows upper limit     

Matteo Vacchi  Monica Montefalcone  Chiara F. Schiaffino  Valeriano Parravicini  Carlo Nike Bianchi  Carla Morri  Marco Ferrari 《Marine pollution bulletin》2014

The upper portion of the meadows of the protected Mediterranean seagrass Posidonia oceanica occurs in the region of the seafloor mostly affected by surf-related effects. Evaluation of its status is part of monitoring programs, but proper conclusions are difficult to draw due to the lack of definite reference conditions. Comparing the position of the meadow upper limit with the beach morphodynamics (i.e. the distinctive type of beach produced by topography and wave climate) provided evidence that the natural landwards extension of meadows can be predicted. An innovative model was therefore developed in order to locate the region of the seafloor where the meadow upper limit should lie in natural conditions (i.e. those governed only by hydrodynamics, in absence of significant anthropogenic impact). This predictive model was validated in additional sites, which showed perfect agreement between predictions and observations. This makes the model a valuable tool for coastal management.  相似文献   

Crustal thickness estimation beneath the southern central Andes at 30°S and 36°S from S wave receiver function analysis     

Benjamin Heit  Xiaohui Yuan  Marcelo Bianchi  Forough Sodoudi  Rainer Kind 《Geophysical Journal International》2008,174(1):249-254

We have used the S wave receiver function (SRF) technique to investigate the crustal thickness beneath two seismic profiles from the CHARGE project in the southern central Andes. A previous study employing the P wave receiver function method has observed the Moho interface beneath much of the profiles. They found, however, that the amplitude of the P to S conversion was diminished in the western part of the profiles and have attributed it to a reduction of the impedance contrast at the Moho due to lower crustal ecologitization. With SRF, we have successfully detected S to P converted waves from the Moho as well as possible conversions from other lithospheric boundaries. The continental South American crust reaches its maximum thickness of ∼70 km (along 30°S between 70°W and 68.5°W) beneath the Principal Cordillera and the Famatina system and becomes thinner towards the Sierras Pampeanas with a thickness of ∼40 km. Negative phases, possibly related to the base of the continental and oceanic lithosphere, can be recognized in the summation traces at different depths. By comparing our results with data obtained from previous investigations, we are able to further constrain the thickness of the crust and lithosphere beneath the central Andes.  相似文献   

A high-pressure serial sampler to measure microbial activity in the deep sea   总被引：1，自引：0，他引：1  

A Bianchi  J Garcin  O Tholosan 《Deep Sea Research Part I: Oceanographic Research Papers》1999,46(12):2129

A high-pressure serial sampler (HPSS) has been developed to obtain microbial activity data unbiased by decompression during retrieval with the same frequency as used for the measurement of other hydrological parameters. We fitted a commercially available multisampling device with eight pressure-retaining vessels. This device allows the collection of eight 500 ml samples of undecompressed water during the same hydrocast to a depth of 3500 m. The HPSS includes a CTD; therefore the eight sampling depths can be selected using the conventional hydrological parameters. During the retrieval and the incubation period pressure conditions of each sampler are permanently recorded on the surface computer. Incubation is in a temperature-controlled water bath to keep the samples in the natural temperature conditions. During the incubation period, several sub-samples may be successively collected without pressure loss within the culture vessel, allowing time-course experiments. During a stratified period, comparison of microbial production rates simultaneously measured on the decompressed and undecompressed seawater samples collected between 850 and 2000 m depth showed that the deep-sea bacteria were affected by decompression during retrieval.  相似文献   

Investigation of Small‐Scale Preferential Flow with a Forced‐Gradient Tracer Test     

Marco Bianchi  Chunmiao Zheng  Geoffrey R. Tick  Steven M. Gorelick 《Ground water》2011,49(4):503-514

A new tracer experiment (referred to as MADE‐5) was conducted at the well‐known Macrodispersion Experiment (MADE) site to investigate the influence of small‐scale mass‐transfer and dispersion processes on well‐to‐well transport. The test was performed under dipole forced‐gradient flow conditions and concentrations were monitored in an extraction well and in two multilevel sampler (MLS) wells located at 6, 1.5, and 3.75 m from the source, respectively. The shape of the breakthrough curve (BTC) measured at the extraction well is strongly asymmetric showing a rapidly arriving peak and an extensive late‐time tail. The BTCs measured at seven different depths in the two MLSs are radically different from one another in terms of shape, arrival times, and magnitude of the concentration peaks. All of these characteristics indicate the presence of a complex network of preferential flow pathways controlling solute transport at the test site. Field‐experimental data were also used to evaluate two transport models: a stochastic advection‐dispersion model (ADM) based on conditional multivariate Gaussian realizations of the hydraulic conductivity field and a dual‐domain single‐rate (DDSR) mass‐transfer model based on a deterministic reconstruction of the aquifer heterogeneity. Unlike the stochastic ADM realizations, the DDSR accurately predicted the magnitude of the concentration peak and its arrival time (within a 1.5% error). For the multilevel BTCs between the injection and extraction wells, neither model reproduced the observed values, indicating that a high‐resolution characterization of the aquifer heterogeneity at the subdecimeter scale would be needed to fully capture 3D transport details.  相似文献