Volunteered geographic information systems: Technological design patterns     

Jos Pablo Gmez‐Barrn  Miguel ngel Manso‐Callejo  Ramn Alcarria 《Transactions in GIS》2019,23(5):976-1007

Volunteered geographic information (VGI) has been studied extensively within various contexts, however, generally focusing on isolated aspects of data. Therefore, we still need to advance the structured knowledge of the mechanisms that affect and support its creation. This article aims to contribute to the integrated study of VGI systems (VGIS) in order to enhance design processes that lead to a more systematic and efficient VGI management. We define VGIS, their main components, and general architectures. Then, we use the service blueprinting technique to conduct the case study of several systems, identifying system actions to find the processes and technologies forming the different functional components of VGIS: elements of the technological infrastructure that implement diverse processes to facilitate participation and data management. Integrated in the data collection component, we also propose a typology of crowdsourcing tasks that—coupled with the functional components—establishes a foundation for VGIS research and design. We characterize these components, arguing that they are necessary in the development of VGIS, however, there is still a need for a more detailed study of the flow of processes and subprocesses and how they work under the criteria of different types of projects to continue facilitating their design.  相似文献   

Refugee research in the shadow of fear     

Bose  Pablo S. 《GeoJournal》2020,87(2):195-207

What does it mean to conduct community-based and praxis-oriented research at a time when those whose lives you study and with whom you work are the subjects of increasing levels of xenophobia, marginalization, and demonization? How does one conceive of research ethics, of the relationship between the roles of scholars, teachers, and citizens in light of such dynamics? In what ways can scholarship help to intervene in the world around us, in particular to improve the perception and amplify the voices of marginalized groups and individuals? This paper considers these issues in the context of research ethics and the growing field of community geography. I draw in particular on an example from a multi-year study of refugee resettlement in non-traditional destinations across the US. When the study began, refugee policies and settlement patterns were little known to the general public in the US. Since then, refugees and migration more broadly have become increasingly prominent and controversial worldwide. In this paper I explore some of the challenges regarding collaborations between university researchers and community partners, highlighting the tensions exposed through the use of the visualization technique known as Photovoice, meant to provide alternative perspectives on ideas for urban change amongst participants. I also consider some ideas for steps to address these challenges, including the building of networks and training for researchers and formalized partnership processes for community groups.

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The influence of shrimp farms organic waste management on chemical water quality   总被引：1，自引：0，他引：1  

Carlos Augusto Ramos e Silva  Pablo Bezerra Dávalos  Leonel da Silveira Lobo Sternberg  Flavo Elano Soares de Souza  Maria Helena Constantino Spyrides  Paulo Sérgio Lucio 《Estuarine, Coastal and Shelf Science》2010

We evaluated the physical–chemical properties and nutrient concentrations in two shrimp ponds under conventional management, intensive (I-P) and semi-intensive (SI-P), and one under organic management (O-P), three days after loading and before stoking. The mean’s total alkalinity concentrations were 2.26 ± 0.04 mM, 2.28 ± 0.01 mM and 2.59 ± 0.01 mM, respectively for I-P, SI-P and O-P. Bicarbonate and carbonate accounted for 62% and 37% in I-P, 64% and 36% in SI-P and 83–17% in O-P, respectively. Aragonite and calcite were oversaturated around Ω = 5. Mean total phosphate (TP) concentrations were 441.37 ± 92.06 μg/L, 449 ± 48 μg/L and 473.64 ± 84.17 μg/L, under I-P SI-P and O-P management respectively. Following this sequence, NO₃⁻ concentration was 2.98 ± 0.7 μg/L, 1.16 ± 0.16 μg/L and 0.32 ± 0.12 μg/L, under I-P, SI-P and O-P management respectively. Thus, the data suggest that different management of farm organic waste leads to different chemical water quality.  相似文献   

Modelling large-scale effects of estuarine and morphodynamic gradients on distribution and abundance of the sandy beach isopod Excirolana armata     

Juan Pablo Lozoya  Julio Gómez  Omar Defeo 《Estuarine, Coastal and Shelf Science》2010

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Aggregate performance in managing marine ecosystems of 53 maritime countries     

Jacqueline Alder  Sarika Cullis-Suzuki  Vasiliki Karpouzi  Kristin Kaschner  Suzanne Mondoux  Wilf Swartz  Pablo Trujillo  Reg Watson  Daniel Pauly 《Marine Policy》2010

Fourteen indicators of marine living resource management performance by country, reflecting both their intention to sustainably use the resource within their Exclusive Economic Zones and the effectiveness of their policies, were developed and the performances of 53 maritime countries were assessed. Four rankings of the countries, which jointly account for over 95 percent of the world's marine fisheries landings, are presented here as aggregated scores of the fourteen indicators, using different schemes for weighting the indicators, each reflective of the management preferences identified by the Global Environment Outlook 4 (GEO4) future development scenarios: Market First; Policy First; Security First; and Sustainability First. The resulting rankings differed substantially between the weighting schemes for the top performing countries but less so for the countries performing poorly.  相似文献   

The continental margin of Uruguay: Crustal architecture and segmentation     

Matías Soto  Ethel MoralesGerardo Veroslavsky  Héctor de Santa AnaNelson Ucha  Pablo Rodríguez 《Marine and Petroleum Geology》2011,28(9):1676-1689

The Uruguayan continental margin comprises three sedimentary basins: the Punta del Este, Pelotas and Oriental del Plata basins, the genesis of which is related to the break-up of Gondwana and the opening of the Atlantic Ocean. Herein the continental margin of Uruguay is studied on the basis of 2D multichannel reflection seismic data, as well as gravity and magnetic surveys. As is typical of South Atlantic margins, the Uruguayan continental margin is of the volcanic rifted type. Large wedges of seaward-dipping reflectors (SDRs) are clearly recognizable in seismic sections. SDRs, flat-lying basalt flows, and a high-velocity lower crust (HVLC) form part of the transitional crust. The SDR sequence (subdivided into two wedges) has a maximum width of 85 km and is not continuous parallel to the margin, but is interrupted at the central portion of the Uruguayan margin. The oceanic crust is highly dissected by faults, which affect post-rift sediments. A depocenter over oceanic crust is reported (deepwater Pelotas Basin), and volcanic cones are observed in a few sections. The structure of continental crust-SDRs-flat flows-oceanic crust is reflected in the magnetic anomaly map. The positive free-air gravity anomaly is related to the shelf-break, while the most prominent positive magnetic anomaly is undoubtedly correlated to the landward edge of the SDR sequence. Given the attenuation, interruption and/or sinistral displacement of several features (most notably SDR sequence, magnetic anomalies and depocenters), we recognize a system of NW-SE trending transfer faults, here named Río de la Plata Transfer System (RPTS). Two tectono-structural segments separated by the RPTS can therefore be recognized in the Uruguayan continental margin: Segment I to the south and Segment II to the north.  相似文献   

3D soft-sediment deformation structures: evidence for Quaternary seismicity in the Madrid basin, Spain     

Pablo G. Silva  Juan C. Cañaveras  Sergio Sanchez-Moral  Javier Lario  Enrique Sanz 《地学学报》1997,9(5-6):208-212

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Estimation of chlorophyll fluorescence under natural illumination from hyperspectral data     

Pablo J Zarco-Tejada  John R Miller  Gina H Mohammed  Thomas L Noland  Paul H Sampson 《International Journal of Applied Earth Observation and Geoinformation》2001,3(4):321

This paper reports a series of laboratory and field measurements of spectral reflectance under artificial and natural light conditions which demonstrate that effects of natural chlorophyll fluorescence are observable in the reflectance red edge spectral region. These are results from the progress made to link physiologically-based indicators to optical indices from hyperspectral remote sensing in the Bioindicators of Forest Sustainability Project. This study is carried out on twelve sites of Acer saccharum M. in the Algoma Region, Ontario (Canada), where field measurements, laboratory-simulation experiments, and hyperspectral CASI imagery have been carried out in 1997, 1998, 1999 and 2000 campaigns. Leaf samples from the study sites have been used for reflectance and transmittance measurements with the Li-Cor Model 1800 integrating sphere apparatus coupled to an Ocean Optics Model ST1000 fibre spectrometer in which the same leaves are illuminated alternatively with and without fluorescence-exciting radiation. A study of the diurnal change in leaf reflectance spectra, combined with fluorescence measurements with the PAM-2000 Fluorometer show that the difference spectra are consistent with observed diurnal changes in steady-state fluorescence. Small canopies of Acer saccharum M. have been used for laboratory measurements with the CASI hyperspectral sensor, and under natural light conditions with a fibre spectrometer in diurnal trials, in which the variation of measured reflectance is shown experimentally to be consistent with a fluorescence signature imposed on the inherent leaf reflectance signature. Such reflectance changes due to CF are measurable under natural illumination conditions, although airborne experiments with the CASI hyperspectral sensor produced promising but less convincing results in two diurnal experiments carried out in 1999 and 2000, where small variations of reflectance due to the effect of CF were observed.  相似文献   

Mechanical aspects of thrust faulting driven by far-field compression and their implications for fold geometry   总被引：1，自引：0，他引：1  

Pablo F. Sanz  Ronaldo I. Borja  David D. Pollard 《Acta Geotechnica》2007,2(1):17-31

In this paper we present a mechanical model that intends to captures the kinematical aspects of thrust fault related folds induced by regional-scale far-field contraction. Fold shapes may be the only surface evidence of the geometry of underlying faults, so complex fault interactions are assessed in terms of how they influence fold geometry. We use the finite element method to model the fold and finite deformation frictional contact to model the activation and evolution of slip throughout preexisting faults. From several simulated 2D fault patterns we infer how one may form an anticline similar to that observed at Sheep Mountain Anticline, Wyoming.  相似文献   

Persistence of lutetium disilicate     

María D. Alba  Pablo Chaín 《Applied Geochemistry》2007

RE₂Si₂O₇ is one of the final products of the chemical interaction of radioactive cation simulators and the silicates used in the engineered barrier of deep geological repositories. The aim of this paper is to study the chemical and structural behaviour of Lu₂Si₂O₇ (Lu as actinide tripositive state simulator) in several different chemical systems. The conditions expected at the repositories are simulated in the laboratory with solutions of different compositions and pH. Both the solid products and remnant solutions were analyzed using techniques that give information on the short- and long-range structural order. The results show good stability of Lu₂Si₂O₇, under the studied conditions, and, therefore, encapsulation of the radioactive actinide cations as a disilicate phase could be considered a viable method to ensure the long-term safety of the repositories.  相似文献