Effectiveness of Neural Kriging for Three-Dimensional Modeling of Sparse and Strongly Biased Distribution of Geological Data with Application to Seafloor Hydrothermal Mineralization     

Koike  Katsuaki  Yono  Oak  de Sá  Vitor Ribeiro  Tomita  Shohei Albert  Nozaki  Tatsuo  Takaya  Yutaro  Komori  Shogo 《Mathematical Geosciences》2022,54(7):1183-1206

Mathematical Geosciences - Three-dimensional modeling of geoscientific data of limited amounts and strongly biased locations is difficult and impractical using almost any method. To obtain a...  相似文献   

enviroCar: A Citizen Science Platform for Analyzing and Mapping Crowd‐Sourced Car Sensor Data          下载免费PDF全文

Arne Bröring  Albert Remke  Christoph Stasch  Christian Autermann  Matthes Rieke  Jakob Möllers 《Transactions in GIS》2015,19(3):362-376

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A textural classification of argillaceous rocks and their durability     

Jordi Corominas  Joan Martínez-Bofill  Albert Soler 《Landslides》2015,12(4):669-687

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Response to: “Critical Analysis of a Hypothesis of the Planetary Tidal Influence on Solar Activity” by S. Poluianov and I. Usoskin     

J. A. Abreu  C. Albert  J. Beer  A. Ferriz-Mas  K. G. McCracken  F. Steinhilber 《Solar physics》2014,289(6):2343-2344

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Baroclinic instability with variable static stability—a design study for a spherical atmospheric model experiment     

Albert C. Glere  William W. Fowlis 《地球物理与天体物理流体动力学》2013,107(1):207-224

Abstract

Exact solutions are obtained for a quasi-geostrophic baroclinic stability problem in which the rotational Froude number (inverse Burger number) is a linear function of the height. The primary motivation for this work was to investigate the effect of a radially-variable, dielectric body force, analogous to gravity, on baroclinic instability for the design of a spherical, synoptic-scale, atmospheric model experiment for a Spacelab flight. Such an experiment cannot be realized in a laboratory on the Earth's surface because the body force cannot be made strong enough to dominate terrestrial gravity. Flow in a rotating, rectilinear channel with a vertically variable body force and with no horizontal shear of the basic state is considered. The horizontal and vertical temperature gradients of the basic and reference states are taken as constants. Consequences of the body force variation and the other assumptions of the model are that the static stability (Brunt-Väisälä frequency squared) and the vertical shear of the basic state flow have the same functional form and that the transverse gradient of the potential vorticity of the basic state vanishes. The solutions show that the stability characteristics of the model are qualitatively similar to those of Eady's model. A short wavelength cutoff and a wavenumber of maximum growth rate are present. Further, the stability characteristics are quantitatively similar to Eady's results for parameters based on the vertically averaged Brunt-Väisälä: frequency. The solutions also show that the temperature amplitude distribution is particularly sensitive to the vertical variation of the static stability. For the static stability and shear decreasing (increasing) with height a relative enhancement of the temperature amplitude occurs at the lower (upper) surface. The other amplitudes and phases are only slightly influenced by the variation. The implication for the Spacelab experiment is that the variable body force will not significantly alter the dynamics from the constant gravity case. The solutions can be relevant to other geophysical fluid flows, including the atmosphere, ocean and annulus system in which the static stability undergoes variation with height.  相似文献   

Holocene and Pleistocene pluvial periods in Yemen,southern Arabia     

Dominik Fleitmann  Stephen J. Burns  Marek Pekala  Augusto Mangini  Abdulkarim Al-Subbary  Mohammad Al-Aowah  Jan Kramers  Albert Matter 《Quaternary Science Reviews》2011,30(7-8):783-787

Arabia is an important potential pathway for the dispersal of Homo sapiens (“out of Africa”). Yet, because of its arid to hyper-arid climate humans could only migrate across southern Arabia during pluvial periods when environmental conditions were favorable. However, knowledge on the timing of Arabian pluvial periods prior to the Holocene is mainly based on a single and possibly incomplete speleothem record from Hoti Cave in Northern Oman. Additional terrestrial records from the Arabian Peninsula are needed to confirm the Hoti Cave record. Here we present a new speleothem record from Mukalla Cave in southern Yemen. The Mukalla Cave and Hoti Cave records clearly reveal that speleothems growth occurred solely during peak interglacial periods, corresponding to Marine Isotope Stages (MIS) 1 (early to mid-Holocene), 5.1, 5.3, 5.5 (Eemian), 7.1, 7.5 and 9. Of these humid periods, highest precipitation occurred during MIS 5.5 and lowest during early to middle Holocene.  相似文献   

Quantifying seasonal export and retention of nutrients in West European lowland rivers at catchment scale     

Jeroen J. M. de Klein  Albert A. Koelmans 《水文研究》2011,25(13):2102-2111

To set accurate critical values for the protection of lakes and coastal areas, it is crucial to know the seasonal variation of nutrient exports from rivers. This article presents an improved method for estimating export and in‐stream nutrient retention and its seasonal variation. For 13 lowland river catchments in Western Europe, inputs to surface water and exports were calculated on a monthly basis. The catchments varied in size (21 to 486 km²), while annual in‐stream retention ranged from 23 to 84% for N and 39 to 72% for P. A novel calculation method is presented that quantifies monthly exports from lowland rivers based on an annual load to the river system. Inputs in the calculation are annual emission to the surface waters, average monthly river discharge, average monthly water temperature and fraction of surface water area in the catchment. The method accounts for both seasonal variation of emission to the surface water and seasonal in‐stream retention. The agreement between calculated values and calibration data was high (N: r² = 0·93; p < 0·001 and P: r² = 0·81; p < 0·001). Validation of the model also showed good results with model efficiencies for the separate catchments ranging from 31 to 95% (average 76%). This indicates that exports of nitrogen and phosphorus on a monthly basis can be calculated with few input data for a range of West European lowland rivers. Further analysis showed that retention in summer is higher than that in winter, resulting in lower summer nutrient concentrations than that calculated with an average annual input. This implies that accurate evaluation of critical thresholds for eutrophication effects must account for seasonal variation in hydrology and nutrient loading. Our quantification method thus may improve the modelling of eutrophication effects in standing waters. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Assessing socio-economic impacts of wave overtopping: An institutional perspective     

Jan Jaap Bouma  Delphine François  Albert Schram  Tom Verbeke 《Coastal Engineering》2009

One way to address the assessment of strategies to control wave overtopping at seawalls and related coastal defence structures is to make use of Cost-Benefit Analysis. The institutional context in which Cost-Benefit Analysis takes place influences decisions on the types of values that are taken into consideration and the subsequent selection of valuation methods. We suggest to consider Cost-Benefit Analysis in a broad institutional framework when decisions are to be made on coastal defence strategies. It is argued that the institutional context provides the rules of the game on how a balance can be found between social, economic and ecologic functions of projects that protect societies against overtopping.  相似文献   

Home range and habitat: Using platial characteristics to define urban areas from the bottom up     

Albert Acedo  Peter A. Johnson 《Transactions in GIS》2020,24(4):819-841

The spatial representation of a city is typically formed by top‐down jurisdictional boundaries. A parallel approach would be to consider representing a city based on platial characteristics, that is, a bottom‐up landscape created through individual and collectively derived representations. This study contributes to this discourse through the exploratory examination of the ecology notions of home range and habitat applied to humans in an urban context. Using spatial data collected through a WebGIS platform, we employ a spatial definition of sense of place and social capital to understand the platial nature of the city and, simultaneously, defining home range and habitat as platial notions. We found spatial variability among individual home range and habitat and the difficulty of traditional administrative boundaries to represent these areas. This research defines and presents home range and habitat to partially describe the emergent nature of platial theory and explores their operationalization at the urban level.  相似文献   

Dependence of sediment sorting on bedload transport phase in a river meander          下载免费PDF全文

Albert Rovira  Francisco Núñez‐González  Carles Ibañez 《地球表面变化过程与地形》2018,43(10):2077-2088

It is widely recognized nowadays that there are at least two different phases of bedload sediment transport in gravel‐bed rivers. However, the transition between these phases is still poorly or subjectively defined, especially at bends in rivers, where cross‐stream sediment transport can strongly influence changes in the texture of the transported sediment. In this paper, we use piecewise models to identify objectively, at two points in the cross‐section of a river bend, the discharge at which the transition between bedload transport phases occurs. Piecewise models were applied to a new bedload data set collected during a wide range of discharges while analysing the associated changes in sediment texture. Results allowed the identification of two well‐differentiated phases of sediment transport (phase I and phase II), with a breakpoint located around bankfull discharge. Associated with each phase there was a change in bedload texture. In phase I there was non‐dominance in the transport of fine or coarse fractions at a particular sampling point; but in phase II bedload texture was strongly linked to the position of the sampling point across the channel. In this phase, fine particles tended to be transported to the inner bank, while coarse sizes were transferred throughout the middle parts of the channel. Moreover, bedload texture at the inner sampling point became bimodal while the transport of pebble‐sized particles was increasing in the central parts of the river channel. It is suggested that this general pattern may be related both to secondary currents, which transfer finer particles from the outer to the inner bank, and to the progressive dismantling of the riverbed surface layer. Copyright © 2018 John Wiley & Sons, Ltd.  相似文献