Site effect and damage distribution in Pujili (Ecuador) after the 28 March 1996 earthquake     

Philippe Guéguen  Jean-Luc Chatelain  Bertrand Guillier  Hugo Yepes  Jose Egred 《Soil Dynamics and Earthquake Engineering》1998,17(5):329-334

The 28 March 1996 earthquake (Mw=5.7) produced extensive damage in Pujili, a small town located in the central part of the Inter-Andean valley of Ecuador. Variations in the damage rate of adobe constructions throughout the city let us suppose a ground motion amplification related to site effects. A site effect study using the H/V spectral ratio confirmed the good agreement with geological formations and showed that a second peak in some soil response appears at sites that are located over a zone of alluvial deposits, in the most damaged area of the city. This second peak is in the frequency range 5–7 Hz, close to the natural response of adobe building frequency. Thus, the second peak seems to increase the damage rate of adobe buildings and may be related to superficial alluvial deposits of a river, acting independently of the rest of the soil column.  相似文献   

REGIONAL GEOGRAPHY OF ANGLO-AMERICA     

Graeme  Wynn 《New Zealand geographer》1975,31(2):196-196

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Ammonoids of the middle/late Anisian boundary (Middle Triassic) and the transgression of the Prezzo Limestone in eastern Lombardy-Giudicarie (Italy)     

Claude Monnet  Peter Brack  Hugo Bucher  Hans Rieber 《Swiss Journal of Geoscience》2008,101(1):61-84

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The systematic position of Equus hydruntinus, an extinct species of Pleistocene equid     

Ariane Burke  Vera Eisenmann  Graeme K. Ambler 《Quaternary Research》2003,59(3):459

Palaeolithic people commonly hunted Equus hydruntinus, an extinct species of equid whose cursorial body proportions suggest an adaptation to semi-arid conditions. Despite the frequency with which it is encountered in fossil deposits, only partial cranial remains have been reported until now. As a result, the systematic affiliation of the species remains a subject of controversy. Two nearly complete E. hydruntinus crania are presented here for the first time. These skulls show that E. hydruntinus is a distinct species, more closely related to the hemiones (Asiatic asses) than to any other equid. This suggests that the social organisation of E. hydruntinus followed one of two known equid sociotypes: resource defense territoriality.  相似文献   

Solving the horizontal conflation problem with a constrained Delaunay triangulation     

Hugo Ledoux  Ken Arroyo Ohori 《Journal of Geographical Systems》2017,19(1):21-42

Datasets produced by different countries or organisations are seldom properly aligned and contain several discrepancies (e.g., gaps and overlaps). This problem has been so far almost exclusively tackled by snapping vertices based on a user-defined threshold. However, as we argue in this paper, this leads to invalid geometries, is error-prone, and leaves several discrepancies along the boundaries. We propose a novel algorithm to align the boundaries of adjacent datasets. It is based on a constrained Delaunay triangulation to identify and eliminate the discrepancies, and the alignment is performed without moving vertices with a snapping operator. This allows us to guarantee that the datasets have been properly conflated and that the polygons are geometrically valid. We present our algorithm, our implementation (based on the stable and fast triangulator in CGAL), and we show how it can be used it practice with different experiments with real-world datasets. Our experiments demonstrate that our approach is highly efficient and that it yields better results than snapping-based methods.  相似文献   

Fishing vs. natural recruitment variation in sandeels as a cause of seabird breeding failure at Shetland: a modelling approach   总被引：2，自引：0，他引：2  

Poloczanska  Elvira S.; Cook  Robin M.; Ruxton  Graeme D.; Wright  Peter J. 《ICES Journal of Marine Science》2004,61(5):788-797

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Spatial structure and geometry of schools of sardine (Sardinops sagax) in relation to abundance, fishing effort, and catch in northern Chile     

Castillo  Jorge; Robotham  Hugo 《ICES Journal of Marine Science》2004,61(7):1113-1119

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Using beryllium-7 to evaluate soil erosion processes in agricultural lands in semiarid regions of Central Argentina     

Juan Pablo de Rosas  Alexander Dario Esquivel  Diego Martinez Heimann  Agustin E. Negri  Flavia Lohaiza  Diego Leonardo Valladares  Alejandro I. Zavala  Hugo Huck  Jimena Juri Ayub 《Environmental Earth Sciences》2018,77(16):587

This work presents the results of a soil erosion study using the ⁷Be technique. This technique estimates the water erosion/deposition from the comparison between ⁷Be soil content of a reference site and an eroded or sedimented site. The soil samples were collected from an agricultural area of the semiarid region of Argentina near San Luis City, which has a marked rainfall season. The area has been used for crop cultivation, being subjected to plowing practices. The ⁷Be in the Reference Site was in the first centimeter of soil, showing the typical exponential decreasing of ⁷Be soil content with depth, with the ⁷Be inventories value being 340?±?50 Bq m^?2 for the dry season and 571?±?48 Bq m^?2 for the rainy season. The ⁷Be technique was applied to a potential eroded site subjected to traditional tillage practices (plowing). A net soil erosion value of 13.5 t ha^?1 (1.35 kg m^?2) was obtained. From the assumptions of the applied technique, we can draw the inference that this erosion was caused by rains produced in the month prior to the date of soil sampling.  相似文献   

Landslide databases in the Geological Surveys of Europe     

Gerardo Herrera  Rosa María Mateos  Juan Carlos García-Davalillo  Gilles Grandjean  Eleftheria Poyiadji  Raluca Maftei  Tatiana-Constantina Filipciuc  Mateja Jemec Auflič  Jernej Jež  Laszlo Podolszki  Alessandro Trigila  Carla Iadanza  Hugo Raetzo  Arben Kociu  Maria Przyłucka  Marcin Kułak  Michael Sheehy  Xavier M. Pellicer  Charise McKeown  Graham Ryan  Veronika Kopačková  Michaela Frei  Dirk Kuhn  Reginald L. Hermanns  Niki Koulermou  Colby A. Smith  Mats Engdahl  Pere Buxó  Marta Gonzalez  Claire Dashwood  Helen Reeves  Francesca Cigna  Pavel Liščák  Peter Pauditš  Vidas Mikulėnas  Vedad Demir  Margus Raha  Lídia Quental  Cvjetko Sandić  Balazs Fusi  Odd Are Jensen 《Landslides》2018,15(2):359-379

Landslides are one of the most widespread geohazards in Europe, producing significant social and economic impacts. Rapid population growth in urban areas throughout many countries in Europe and extreme climatic scenarios can considerably increase landslide risk in the near future. Variability exists between European countries in both the statutory treatment of landslide risk and the use of official assessment guidelines. This suggests that a European Landslides Directive that provides a common legal framework for dealing with landslides is necessary. With this long-term goal in mind, this work analyzes the landslide databases from the Geological Surveys of Europe focusing on their interoperability and completeness. The same landslide classification could be used for the 849,543 landslide records from the Geological Surveys, from which 36% are slides, 10% are falls, 20% are flows, 11% are complex slides, and 24% either remain unclassified or correspond to another typology. Most of them are mapped with the same symbol at a scale of 1:25,000 or greater, providing the necessary information to elaborate European-scale susceptibility maps for each landslide type. A landslide density map was produced for the available records from the Geological Surveys (LANDEN map) showing, for the first time, 210,544 km² landslide-prone areas and 23,681 administrative areas where the Geological Surveys from Europe have recorded landslides. The comparison of this map with the European landslide susceptibility map (ELSUS 1000 v1) is successful for most of the territory (69.7%) showing certain variability between countries. This comparison also permitted the identification of 0.98 Mkm² (28.9%) of landslide-susceptible areas without records from the Geological Surveys, which have been used to evaluate the landslide database completeness. The estimated completeness of the landslide databases (LDBs) from the Geological Surveys is 17%, varying between 1 and 55%. This variability is due to the different landslide strategies adopted by each country. In some of them, landslide mapping is systematic; others only record damaging landslides, whereas in others, landslide maps are only available for certain regions or local areas. Moreover, in most of the countries, LDBs from the Geological Surveys co-exist with others owned by a variety of public institutions producing LDBs at variable scales and formats. Hence, a greater coordination effort should be made by all the institutions working in landslide mapping to increase data integration and harmonization.  相似文献   

Continuous characterization of dynamic soil behavior by Digital Image Correlation in a transparent shear laminar box     

Segaline  Hugo  Sáez  Esteban  Ubilla  Javier 《Acta Geotechnica》2022,17(6):2395-2414

This work characterizes and analyzes the dynamic behavior of a sandy soil due to one-dimensional propagation of mechanical waves into a transparent laminar shear box. The outstanding char acteristic of this laminar box is a transparent front glass, which allows monitoring the soil behavior by a high-speed and high-resolution camera, and then computing the displacement field in the soil by the Digital Image Correlation (DIC) technique. The response of the laminar container was evaluated using ambient vibrations, harmonic signals and Ricker wavelets. Afterward, dynamic soil properties derived from DIC analysis are compared against theoretical and laboratory results. Finally, a numerical simulation is carried out using the finite element method, where the influence of the lateral friction of the glass on the motion is assessed and discussed. It is concluded that the transparent laminar shear box provides a useful tool for studying the continuous dynamic soil behavior; additionally, the transparent boundary has a minor impact on the results and a minimum observable cyclic shear strain of about 10–4 was reached.

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