Surrogate-based parameter inference in debris flow model     

Maria Navarro  Olivier P. Le Maître  Ibrahim Hoteit  David L. George  Kyle T. Mandli  Omar M. Knio 《Computational Geosciences》2018,22(6):1447-1463

This work tackles the problem of calibrating the unknown parameters of a debris flow model with the drawback that the information regarding the experimental data treatment and processing is not available. In particular, we focus on the evolution over time of the flow thickness of the debris with dam-break initial conditions. The proposed methodology consists of establishing an approximation of the numerical model using a polynomial chaos expansion that is used in place of the original model, saving computational burden. The values of the parameters are then inferred through a Bayesian approach with a particular focus on inference discrepancies that some of the important features predicted by the model exhibit. We build the model approximation using a preconditioned non-intrusive method and show that a suitable prior parameter distribution is critical to the construction of an accurate surrogate model. The results of the Bayesian inference suggest that utilizing directly the available experimental data could lead to incorrect conclusions, including the over-determination of parameters. To avoid such drawbacks, we propose to base the inference on few significant features extracted from the original data. Our experiments confirm the validity of this approach, and show that it does not lead to significant loss of information. It is further computationally more efficient than the direct approach, and can avoid the construction of an elaborate error model.  相似文献   

Influence of a Drought Event on Hydrological Characteristics of a Small Estuary on the Amazon Mangrove Coast     

Luci Cajueiro Carneiro Pereira  Ádila Kelly Rodrigues da Costa  Rauquírio Marinho da Costa  André Magalhães  Manuel de Jesus Flores-Montes  José A. Jiménez 《Estuaries and Coasts》2018,41(3):676-689

The effects of atypical climatic conditions, such as those of a drought event, are remarkably accentuated in minor estuaries filled with sediments and with reduced or sporadic freshwater input, where the salinity intrusion is pronounced. To understand these effects, hydrological and hydrodynamic parameters were evaluated during a drought period in a small estuary located on the eastern Amazon coast in northern Brazil. Five campaigns were conducted between June 2012 and June 2013. Samples were collected from the surface and bottom layer every 3 h over a 25-h period at three stations of the Taperaçu Estuary. To compare drought and post-drought periods, in terms of salinity and chlorophyll-a, data was recorded until June 2015. Taperaçu is a relatively shallow estuary of the Amazon coastal zone, which is characterized by the absence of any direct fluvial discharge, although it does receive freshwater input from adjacent wetlands, as well as less saline waters from the Caeté Estuary through the Taici Creek. Hydrological variables were controlled by rainfall levels and the tidal range, and the water became more saline and more oxygenated, with reduced dissolved nutrient and chlorophyll-a concentrations when precipitation decreased. A significant variation was found between the months of June 2012 (most intense drought) and 2013 (less intense drought). The connection to the neighboring Caeté Estuary and adjacent mangroves and wetlands contributed to the influx of nutrient-enriched waters. Overall, then, it is hoped that the results of this study can contribute to the understanding of the effects of drought events in other minor estuaries on the highly indented Amazon coast, as well as in other areas of the equatorial zone with similar environmental characteristics.  相似文献   

The Tertiary dike magmatism in the Southern Alps: geochronological data and geodynamic significance     

Maria Aldina Bergomi  Stefano Zanchetta  Annalisa Tunesi 《International Journal of Earth Sciences》2015,104(2):449-473

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Bay breeze influence on surface ozone at Edgewood,MD during July 2011     

Ryan M. Stauffer  Anne M. Thompson  Douglas K. Martins  Richard D. Clark  Daniel L. Goldberg  Christopher P. Loughner  Ruben Delgado  Russell R. Dickerson  Jeffrey W. Stehr  Maria A. Tzortziou 《Journal of Atmospheric Chemistry》2015,72(3-4):335-353

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Correction to: A novel methodological approach for land subsidence prediction through data assimilation techniques     

Gazzola  Laura  Ferronato  Massimiliano  Frigo  Matteo  Janna  Carlo  Teatini  Pietro  Zoccarato  Claudia  Antonelli  Massimo  Corradi  Anna  Dacome  Maria Carolina  Mantica  Stefano 《Computational Geosciences》2021,25(5):1751-1751

Computational Geosciences - A Correction to this paper has been published: https://doi.org/10.1007/s10596-021-10079-6  相似文献   

Assessment of future trends on groundwater quality in a nitrate vulnerable zone (Esposende–Vila do Conde sector,NW Portugal): towards a combined conceptual and mass transport modelling     

Zeferino  Joel  Carvalho  Maria Ros&#;rio  Lopes  Ana Rita  Jesus  Ros&#;rio  Afonso  Maria Jos&#;  Freitas  Liliana  Carvalho  Jos&#; Martins  Chamin&#;  Helder I. 《Hydrogeology Journal》2021,29(6):2267-2283

Hydrogeology Journal - Nitrate contamination of groundwater is an important public health issue worldwide. For environmental and public health reasons, water should not contain more than...  相似文献   

In Situ Oxygen Isotope Determination in Serpentine Minerals by SIMS: Addressing Matrix Effects and Providing New Insights on Serpentinisation at Hole BA1B (Samail ophiolite,Oman)     

Maria Rosa Scicchitano  Michael J. Spicuzza  Eric T. Ellison  David Tuschel  Alexis S. Templeton  John W. Valley 《Geostandards and Geoanalytical Research》2021,45(1):161-187

The ability to constrain the petrogenesis of multiple serpentine generations recorded at the microscale is crucial for estimating the extent and conditions of modern versus fossil serpentinisation in ophiolites. To address matrix bias effects during oxygen isotope analysis by SIMS, we present the first investigation analysing antigorite in the compositional range Mg# = 77.5–99.5 mole %, using a CAMECA IMS‐1280 secondary ion mass spectrometer. Spot‐to‐spot homogeneity is ≤ 0.5‰ (2s) for the new antigorite reference materials. The relative bias between antigorite reference materials with different Mg/Fe ratios is described by a second‐order polynomial, and a maximum difference in bias of ~ 1.8‰ was measured for Mg# ~ 78 to 100. We observed a bias up to ~ 1.0‰ between lizardite and antigorite attributed to their different crystal structures. Orientation effects up to ~ 1‰ were observed in chrysotile. The new analytical protocol allowed the identification of oxygen isotope zoning up to ~ 7‰ in serpentine minerals from two serpentinites recovered from an area of active serpentinisation in the Samail ophiolite. Thus, in situ analysis is capable of resolving isotopic heterogeneity that may directly reflect changes in the physical and chemical conditions of multiple serpentinisation events in the Samail ophiolite.  相似文献   

Sedimentology of a Late Quaternary lacustrine record from the south-eastern Carpathian Basin     

Christian Zeeden  Ulrich Hambach  Nicole Klasen  Peter Fischer  Philipp Schulte  Janina J. Nett  Daniel Veres  Igor Obreht  Wei Chu  Maria Papadopoulou  Finn Viehberg  Frank SchÄBitz  Milivoj B. Gavrilov  Slobodan B. MarkoviĆ  Andreas VÖTT  Frank Lehmkuhl 《第四纪科学杂志》2021,36(8):1414-1425

The Upper Pleistocene geoarchives in the south-eastern Carpathian Basin are represented predominantly by loess–palaeosol records. In 2015, a 10 m sediment core composed of clay-rich lacustrine sediments was recovered by vibracoring a dry lake basin located between the Vršac Mountains (Serbia) and the Banat Sands in the south-eastern Carpathian Basin; a location relevant for placing regional archaeological results in a palaeoenvironmental context. Here, we present results from geoelectrical prospection and a lithostratigraphic interpretation of this sequence supported by a detailed granulometric study supplemented by ostracod analysis. An age model based on luminescence dating is discussed against sedimentological proxy data and its implication for palaeoenvironmental change. The cores show a stratigraphy of lighter ochre-coloured and darker greyish sediment, related to the deposition of clay and silt trapped in an aquatic environment. Geophysical measurements show ~20 m thick lacustrine sediments. The grain-size distributions including the variability in fine clay are indicative of a lacustrine environment. Fine particles were brought into the depositional environments by aquatic input and settled from suspension; also, direct dust input is constrained by grain-size results. Riverine input and aeolian dust input interplayed at the locality.  相似文献   

Activity maps of multi-source mudslides from the Daunia Apennines (Apulia,southern Italy)     

Spalluto  Luigi  Fiore  Antonio  Miccoli  Maria Nilla  Parise  Mario 《Natural Hazards》2021,105(1):277-292

Natural Hazards - Flooding poses a serious public health hazard throughout the world. Flood modeling is an important tool for emergency preparedness and response, but some common methods require a...  相似文献   

远震数据显示贝加尔裂谷带北穆伊斯克(Severomuysk)段地壳和上地幔的精细结构     

Valentina V. MORDVINOVA  Maria A. KHRITOVA  Elena A. KOBELEVA  Mikhail M. KOBELEV  Evgeniy Kh. TURUTANOV  Victor S. KANAYKIN 《地学前缘》2022,29(2):378-392

通过贝加尔裂谷系统北穆伊斯克(Severomuysk)段的密集地震台站线性网络获得的远距离强震记录,并利用P波接收函数技术,揭示了地壳和上地幔顶部的复杂分层块状结构。横波速度的分布表明构成北穆伊斯克地壳的地块具有不同性质。这些地块的西部聚散和地壳下部的分层证实了该地区隆起的堆积-碰撞起源。位于西伯利亚克拉通变薄的倾斜边缘上的北穆伊斯克段解释了该地区地壳碰撞效应的强度。2015年地震的震中深度与Muyakan 凹陷地壳上部的明显速度差异存在令人信服的相关性。  相似文献