Data trustworthiness and user reputation as indicators of VGI quality     

Paolo Fogliaroni  Fausto D’Antonio 《地球空间信息科学学报》2018,21(3):213-233

ABSTRACT

Volunteered geographic information (VGI) has entered a phase where there are both a substantial amount of crowdsourced information available and a big interest in using it by organizations. But the issue of deciding the quality of VGI without resorting to a comparison with authoritative data remains an open challenge. This article first formulates the problem of quality assessment of VGI data. Then presents a model to measure trustworthiness of information and reputation of contributors by analyzing geometric, qualitative, and semantic aspects of edits over time. An implementation of the model is running on a small data-set for a preliminary empirical validation. The results indicate that the computed trustworthiness provides a valid approximation of VGI quality.  相似文献   

Place-making at the frontier of Brazilian agribusiness     

Antonio Augusto Rossotto Ioris 《GeoJournal》2018,83(1):61-72

The intricacies of one of the most relevant agribusiness frontiers in the world today—the north of the State of Mato Grosso, in the southern section of the Amazon, Brazil—are considered through a critical examination of place-making. Vast areas of Amazon rainforest and savannah vegetation were converted there, since the 1970s, into places of intensive soybean farming, basically to fulfil exogenous demands for land and agriculture production. The present assessment goes beyond the configuration of new places at the agricultural frontier, and starts with a qualitative intellectual jump: from place-making on the frontier to place-making as an ontological frontier in itself. It means that, instead of merely studying the frontier as a constellation of interconnected places, we examine the politicised genesis of the emerging places and their trajectory under fierce socio-ecological disputes. The consideration of almost five decades of intense historic-geographical change reveals an intriguing dialectics of displacement (of previous socio-ecological systems, particularly affecting squatters and indigenous groups, in order to create opportunities for migrants and companies), replacement (of the majority of disadvantaged farmers and poor migrants, leading to land concentration, widespread financialisation and the decisive influence of transnational corporations) and misplacement (which is the synthesis of displacement and replacement, demonstrated by mounting risks and a pervasive sentiment of maelstrom). Overall, there was nothing inevitable in the process of rural and regional development, but the problems, conflicts and injustices that characterise its turbulent geographical trajectory were all more or less visible from the outset.  相似文献   

Perspectives for Distributed Observations of Near-Earth Space Using a Russian–Cuban Observatory     

D. V. Bisikalo  I. S. Savanov  S. A. Naroenkov  M. A. Nalivkin  A. S. Shugarov  N. S. Bakhtigaraev  P. A. Levkina  M. A. Ibragimov  E. Yu. Kil’pio  M. E. Sachkov  A. P. Kartashova  A. M. Fateeva  Marta R. Rodriguez Uratsuka  Ramses Zaldivar Estrada  Antonio Alonsa Diaz  Omar Pons Rodríguez  Fidel Hernandes Figuera  Maritza Garcia Garcia 《Astronomy Reports》2018,62(6):367-377

The creation of a specialized network of large, wide-angle telescopes for distributed observations of near-Earth space using a Russian–Cuban Observatory is considered. An extremely important goal of routine monitoring of near-Earth and near-Sun space is warding off threats with both natural and technogenic origins. Natural threats are associated with asteroids or comets, and technogenic threats with man-made debris in near-Earth space. A modern network of ground-based optical instruments designed to ward off such threats must: (a) have a global and, if possible, uniform geographic distribution, (b) be suitable for wide-angle, high-accuracy precision survey observations, and (c) be created and operated within a single network-oriented framework. Experience at the Institute of Astronomy on the development of one-meter-class wide-angle telescopes and elements of a super-wide-angle telescope cluster is applied to determine preferences for the composition of each node of such a network. The efficiency of distributed observations in attaining maximally accurate predictions of the motions of potentially dangerous celestial bodies as they approach the Earth and in observations of space debris and man-made satellites is estimated. The first estimates of astroclimatic conditions at the proposed site of the future Russian–Cuban Observatory in the mountains of the Sierra del Rosario Biosphere Reserve are obtained. Special attention is given to the possible use of the network to carry out a wide range of astrophysical studies, including optical support for the localization of gravitational waves and other transient events.  相似文献   

Linking Palaeozoic palaeogeography of the Betic Cordillera to the Variscan Iberian Massif: new insight through the first conodonts of the Nevado-Filábride Complex     

Rodríguez-Cañero  Rosario  Jabaloy-Sánchez  Antonio  Navas-Parejo  Pilar  Martín-Algarra  Agustín 《International Journal of Earth Sciences》2018,107(5):1791-1806

International Journal of Earth Sciences - Graphite-rich metamorphic limestones included within low-grade black schists of the lowest Nevado-Filábride tectonic unit in the Sierra de Baza...  相似文献   

Rockfall risk management using a pre-failure deformation database     

Ryan A. Kromer  Emily Rowe  Jean Hutchinson  Matt Lato  Antonio Abellán 《Landslides》2018,15(5):847-858

Terrestrial laser scanning (TLS) monitoring has been used to estimate the location, volume, and kinematics of a variety of small magnitude rockfalls before failure (1–1000 m³ range), and in some cases, potential failure time has been assessed through the application of inverse velocity methods. However, our current understanding of rock slope pre-failure behavior for this magnitude range and prediction ability is based on observations of a small number of failure case histories. In this study, a pre-failure deformation database was constructed for rockfall volumes exceeding 0.1 m³, observed over a 1252-day study interval at the Goldpan rock slope, British Columbia, Canada, in order to better understand the pre-failure behavior of rock slopes and provide an empirical means of estimating temporal failure ranges. Repeated TLS datasets were acquired at an average scanning interval of 2–3 months. A total of 90 rockfall events were recorded at this site, during this time period, of which 64 (71%) exhibited measurable deformation prior to failure. Classification of rockfalls by volume suggests that a scale dependency may exist, as deformation was detected for a greater proportion of rockfalls >?5 m³ (92%) than for smaller rockfalls in the range of 0.1–0.5 m³ (61%). A lower rate of pre-failure deformation detection was also reported for planar sliding failures as compared with wedge or toppling failures, suggesting that deformation was less easily detected for these failure types. This study proposes and implements a framework for rockfall assessment and forecasting that does not require continuous monitoring of deformation.  相似文献   

Post-processing of sequential indicator simulation realizations for modeling geologic bodies     

Jorge Kazuo Yamamoto  Paulo Milton Barbosa Landim  Antonio Tadashi Kikuda  Claudio Benedito Baptista Leite  Santiago Diaz Lopez 《Computational Geosciences》2015,19(1):257-266

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A Multistep Methodology for Building a Stochastic Model of Gold Grades in the Disseminated and Complex Deposit of Casas Novas in Alentejo,Southern Portugal          下载免费PDF全文

Filipa Vieira Matias  Jose Antonio Almeida  Martim Chichorro 《Resource Geology》2015,65(4):361-374

This paper proposes a multistep approach for creating a 3D stochastic model of gold grades in a complex disseminated auriferous deposit located in the Alentejo region, southern Portugal. The approach involves the following steps: (i) the creation of a 3D low‐resolution vector object model of two geological domains that better discriminate gold grades; (ii) the definition of three intervals for gold grades (low, intermediate, and high values); (iii) the estimation of the probability of each grid block belonging to each interval constrained by the geological domains; (iv) the calculation of local conditional cumulative distribution functions (CCDFs) of gold grades, for each block, taking into account the geological domains and the borehole data; and finally (v) the simulation of images of gold grades. The results demonstrate the usefulness and accuracy of the proposed procedure, as they are in compliance with the conceptual model, the distribution laws are conditioned by the geological domains, and the transition of grades between domains is continuous.  相似文献   

Variations in cereal crop phenology in Spain over the last twenty-six years (1986–2012)     

Jose Oteros  Herminia García-Mozo  Roser Botey  Antonio Mestre  Carmen Galán 《Climatic change》2015,132(4):545-558

Over recent years, the Iberian Peninsula has witnessed an increase both in temperature and in rainfall intensity, especially in the Mediterranean climate area. Plant phenology is modulated by climate, and closely governed by water availability and air temperature. Over the period 1986–2012, the effects of climate change on phenology were analyzed in five crops at 26 sites growing in Spain (southern Europe): oats, wheat, rye, barley and maize. The phenophases studied were: sowing date, emergence, flag leaf sheath swollen, flowering, seed ripening and harvest. Trends in phenological response over time were detected using linear regression. Trends in air temperature and rainfall over the period prior to each phenophase were also charted. Correlations between phenological features, biogeographical area and weather trends were examined using a Generalized Lineal Mixed Model approach. A generalized advance in most winter-cereal phenophases was observed, mainly during the spring. Trend patterns differed between species and phenophases. The most noticeable advance in spring phenology was recorded for wheat and oats, the “Flag leaf sheath swollen” and “Flowering date” phenophases being brought forward by around 3 days/year and 1 day/year, respectively. Temperature changes during the period prior to phenophase onset were identified as the cause of these phenological trends. Climate changes are clearly prompting variations in cereal crop phenology; their consequences could be even more marked if climate change persists into the next century. Changes in phenology could in turn impact crop yield; fortunately, human intervention in crop systems is likely to minimize the negative impact.  相似文献   

The influence of environmental variability of a coastal lagoon ecosystem on genetic diversity and structure of white seabream [Diplodus sargus (Linnaeus 1758)] populations          下载免费PDF全文

Raquel Hernández‐García  Irene Muñoz  Antonio López‐Capel  Concepción Marcos  Ángel Pérez‐Ruzafa 《Marine Ecology》2015,36(4):1144-1154

As coastal lagoons serve as nursery areas for some marine and estuarine fish, selective pressures of these brackish or hypersaline lagoons may influence the genetic structure of species and populations. We examined spatial and temporal genetic patterns at eight microsatellite loci in white seabream [Diplodus sargus (Linnaeus 1758)] recruits from the Mar Menor (Southeast Spain) and compared these loci with those in coastal populations from the open sea, observing a high degree of genetic diversity and spatio‐temporal genetic stability. However, the results suggest the presence of subpopulations or genetic substructures in the Mar Menor D. sargus population that could be interpreted as a homogeneous mixture of individuals from three differentiated subpopulations in the Mediterranean and evidence of the Wahlund effect. It also suggests that D. sargus adults return to their original spawning habitat, thus conserving the genetic differences among the respective populations over time. Overall, this study demonstrates the importance of the Mar Menor coastal lagoon as a nursery area for the conservation of genetic diversity of D. sargus populations.  相似文献   

Stable isotope systematics and fluid inclusion studies in the Cu–Au Visconde deposit,Carajás Mineral Province,Brazil: implications for fluid source generation     

Antonia Railine da Costa Silva  Raimundo Netuno Nobre Villas  Jean-Michel Lafon  Gustavo Souza Craveiro  Valderez Pinto Ferreira 《Mineralium Deposita》2015,50(5):547-569

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