Self-explanatory or just easy-to-use? A theoretical approach to the emancipatory potential of volunteered geographic information (VGI)

Volunteered geographic information (VGI) has fundamentally changed the way in which geoinformation is generated, distributed and handled. It entails manifold practices and discourses which are currently investigated from both affirmative and critical perspectives. Expanding on the range of theoretical approaches to VGI, this article explores the condition and the limits of VGI from a social theory perspective to explore the following questions: what is the basic structure of VGI both as a form of practice and a form of knowledge? What are aspects of integration and aspects of divergence with regard to VGI practices? Are there inherent limitations to VGI practices especially with regard to its emancipatory and educational potential? To approach these issues several established analytical frameworks are discussed, and a specific categorization of VGI’s symbolic geographies as interaction content will be introduced. Based on this categorization two opposed types of interaction practice can be distinguished: While information on VGI gathering and processing as a part of interaction content is vital to a competent use and deeper understanding of the system (“self-explanatory”) many interface designs have a very limited output in order to promote user-friendliness (“easy-to-use”). While the latter may increase the popularity of VGI it also limits interaction language to everyday language, to familiar spatial vocabularies of place, city, region, landscape or nation—instead of mediating technology’s spatialities or exploring more innovative ways of spatial representation.     

Confronting the data-divide in a time of spatial turns and volunteered geographic information

Geography is enjoying a period of unparalleled visibility, driven by the growing use of geographic methods and concepts across the sciences and humanities—the so-called spatial turn—and the pervasive use of geospatial Web technologies and their concomitant influence on society, especially the phenomenon of volunteered geographic information (VGI). The field of public health is beginning to harness spatiality with gusto; however, the geospatial Web and its social phenomena are underexplored in this context even though they may be particularly useful for public health enquiry, especially in low-resource settings that lack traditional data collection mechanisms. A case study framed within these two current phenomena is presented to illustrate the influence of geography and its potential for addressing the data-divide—the disparity in availability of data for scientific enquiry and decision-making most felt in low-and middle income countries. A facilitated VGI data collection initiative collected public health-related injury data in Cape Town, South Africa, as a pragmatic alternative given the lack of data from traditional sources. Emergency medical services personnel interacted with a GeoWeb interface to volunteer their informed opinions of high-incident injury locations. Previously unrecorded injury location data were created, and combined with traditional injury data for use in an ongoing study examining the environmental determinants of injury in this setting, which speaks to the possibility for hybrid authoritative/asserted data collection strategies. This study speaks to the growing influence of geography and one of its driving forces, the techno-social revolution in geospatial technology and data. Future work should continue to examine their potential to address the data-divide.     

Discovering points of interest from users’ map annotations

One of the potential problems of volunteered geographic information (VGI) is ensuring its quality. Innocent mistakes and intentional falsehoods can reduce not only the quality of the information, but also people’s confidence in VGI as a legitimate source of data. We present a case study in VGI that addresses the quality problem by aggregating input from many different people. Specifically, we present a technique to maintain a comprehensive list of points of interest (POI) for digital maps. This is traditionally difficult, because new POI are created, because some POI are known only locally, and because some POI have multiple names. We address this problem by exploiting map annotations contributed by regular, online map users. Our institution’s mapping Web site allows users to create arbitrary collections of geographically anchored pushpins that are annotated with text. Our data mining solution finds geometric clusters of these pushpins and examines the pushpins’ text and other features for likely POI names. For instance, if a given text phrase is mentioned frequently in a cluster, but infrequently elsewhere, this increases our confidence that this phrase names a POI. We tested the quality of our results by asking 100 local residents whether or not the POI we found were correct, and our user study told us we were generally successful. We also show how we can use the same user-annotated pushpins to assess the popularity of existing POI, which is a guide for which ones to display on a map.     

The credibility of volunteered geographic information

The proliferation of information sources as a result of networked computers and other interconnected devices has prompted significant changes in the amount, availability, and nature of geographic information. Among the more significant changes is the increasing amount of readily available volunteered geographic information. Although volunteered information has fundamentally enhanced geographic data, it has also prompted concerns with regard to its quality, reliability, and overall value. This essay situates these concerns as issues of information and source credibility by (a) examining the information environment fostering collective information contribution, (b) exploring the environment of information abundance, examining credibility and related notions within this environment, and leveraging extant research findings to understand user-generated geographic information, (c) articulating strategies to discern the credibility of volunteered geographic information (VGI), including relevant tools useful in this endeavor, and (d) outlining specific research questions germane to VGI and credibility.     

Diversity in volunteered geographic information: comparing OpenStreetMap and Wikimapia in Jerusalem

While the term “volunteered geographic information” (VGI) has become a buzzword in debates on the geoweb, online cartography and digital geoinformation, the scope and reach of VGI remains underexplored. Drawing on literature on social implications of VGI, this article, firstly, explores differences between VGI initiatives at the example of a comparative case study on social biases within data of OSM and Wikimapia in the fragmented social setting of Jerusalem, Israel. The results of this analysis turn out to be highly contradictive between both projects, which challenges widely accepted assumptions on the imprint of social inequalities and digital divides on VGI. This observation guides, secondly, a discussion of diversity within the category of VGI. Arguing that mapping communities, data formats and knowledge types behind VGI are extremely dissimilar, the paper proceeds by questioning the consistency and utility of VGI as a category. Seeking for a more comprehensive typology of VGI, Edney’s notion of cartographic modes will be presented as an approach towards a more contextualized understanding of VGI projects by embracing their underlying cultural, social and technical relations. Consequently, the paper suggests empirical research on the cartographic modes of a broad series of VGI projects through qualitative and quantitative methods alike.     

Volunteered Geographic Information constructions in a contested terrain: A case of OpenStreetMap in China

The recent explosive growth of user-generated geographic information has drawn significant attention from GIS scholars and human geographers. Volunteered Geographic Information (VGI) here refers to a key component of such a phenomenon, comprising both a range of practices of geographic information production and dissemination by volunteers as well as new forms of geospatial data produced and curated through various interactive online platforms and mobile devices such as OpenStreetMap (OSM) and Google Maps. VGI constructions have raised questions on spatial knowledge, power, and context. Through a study that examines social constructions of OSM in China, this paper makes two contributions to the existing literature: providing a political economic account of VGI constructions in China and exploring legalities in VGI research. Informed by research in critical GIS, this paper traces political economic transitions in relation to OSM constructions and examines OSM contributors' experiences and how these experiences constitute OSM development and usage. Drawing upon law and society research, this paper investigates how OSM mappers encounter the state's regulatory scheme of online mapping. This legality perspective of spatial data production and usage is a topic rarely explored in VGI studies. With interview data and document analysis, this paper unravels processes of powerful state institutional arrangements to control and invest in VGI simultaneously, entrepreneurs' interest in developing location-based services using VGI data, and experiences from a tech-savvy group in exploring and making VGI. While individual experiences vary, they show efforts of questioning embedded power relations shaping spatial data production in these continuously evolving, contested technoscientific and social landscapes.     

大牛地气田区地下水水质模糊综合评价

自20世纪20年代以来,出现了30多种水质评价的研究方法。但由于水质等级与评价因子间复杂的非线性关系,以及水体污染的模糊性和随机性,地下水水质评价至今没有一个被广泛接受的评价模型。现阶段,地理信息系统（GIS）技术被广泛应用到水质评价中,在此基础上提出了一系列新的水质评价模式和理论。文章以大牛地气田区浅层地下水为研究对象,利用ArcGIS技术,将GIS与改进的模糊综合评价模型结合,建立基于GIS的地下水水质模糊综合评价模型,并应用于研究区地下水水质评价。同时将基于GIS的模糊综合评价结果和传统的内梅罗指数法进行对比,验证新方法在地下水水质评价工作中的合理性与可靠性。结果表明:（1）大牛地气田浅层地下水水质状况总体良好,以Ⅰ类和Ⅲ类水为主,局部地区浅层地下水中氨氮超标,水质较差;（2）模糊综合评价法与GIS的有效结合,实现了地下水水质模糊综合评价的系统化和可视化;（3）相对于内梅罗指数法,基于GIS的地下水水质模糊综合评价模型综合考虑了各评价因子对水质的影响,能够更加客观、合理地评价研究区地下水水质。     

Is VGI participation? From vernal pools to video games

This paper examines the relationship between public participatory GIS (PPGIS) and volunteered geographic information (VGI). A brief review of the history of PPGIS reveals similarities between the two but also provides examples of how these two areas have developed in ways that cause the boundaries between them to be unclear at times. As evidence for advancing this conversation, 2 case studies are presented: volunteers mapping vernal pools and park design in Second Life. These case studies demonstrate both the intertwined nature of some aspects of VGI and PPGIS, while also showing some aspects of divergence.     

When citizens choose not to participate in volunteering geographic information to e-governance: a case study from Mexico

Citizen participation is a crucial democratic practice in many western societies. In contemporary societies, different social agents utilise information and communication technology using Internet-based systems, to establish two-way communication in order to promote citizen participation. One such approach is volunteered geographical information (VGI). It is considered that VGI provides a new space for citizen engagement, as well as an arena for political contestation, however little attention has been paid to the reasons, drivers and limitations for voluntary citizen participation. Although there is an extensive literature on both VGI and citizen participation, this rarely considers how much citizen participation is necessary to run a VGI platform, what are the drivers for non-participation, and what happens within a democratic political space when citizens are apparently not interested to participate with a VGI deployment These topics are explored in this paper, through the lens of a particular case study of a University deployment for VGI developed in Mexico and a wider analysis of other VGI deployments taken from the literature. By critically assessing the extent to which the VGI deployments have enabled citizen participation, and the degree and quality of this participation, we draw conclusions as to how far and under what circumstances VGI can support government agencies to engage citizens in a meaningful dialogue as part of democratic governance initiatives. This leads us to identify key areas for further research by geographers and related social scientists exploring these socio-technical systems and their effects on democratic societies.     

Site selection for drinking-water pumping boreholes using a fuzzy spatial decision support system in the Korinthia prefecture,SE Greece

The implementation of a geographic information system (GIS)/fuzzy spatial decision support system in the selection of sites for drinking-water pumping boreholes is described. Groundwater is the main source of domestic supply and irrigation in Korinthia prefecture, south-eastern Greece. Water demand has increased considerably over the last 30 years and is mainly met by groundwater abstracted via numerous wells and boreholes. The definition of the most “suitable” site for the drilling of new boreholes is a major issue in this area. A method of allocating suitable locations has been developed based on multicriteria analysis and fuzzy logic. Twelve parameters were finally involved in the model, prearranged into three categories: borehole yield, groundwater quality, and economic and technical constraints. GIS was used to create a classification map of the research area, based on the suitability of each point for the placement of new borehole fields. The coastal part of the study area is completely unsuitable, whereas high values of suitability are recorded in the south-western part. The study demonstrated that the method of multicriteria analysis in combination with fuzzy logic is a useful tool for selecting the best sites for new borehole drilling on a regional scale. The results could be used by local authorities and decision-makers for integrated groundwater resources management.     

Volunteered geographic information and networked publics? Politics of everyday mapping and spatial narratives

The issue of a changing public that undertakes and underpins Volunteered geographic information (VGI) practices has not been discussed in depth in the existing literature. This paper seeks to tackle this issue of publics regarding the intersection between VGI and public participation GIS. I draw upon the notion of “networked publics” to illustrate the complexities of social relations intersecting with VGI practices. Networked publics involve a connected set of social and technological developments associated with the growing engagement with digitally connected media. Networked publics embody several major characteristics including multiple memberships spanning over vast locations and possibilities for horizontal connections and bottom-up engagements. I argue that the emergence and proliferation of VGI reflect the major characteristics of networked publics. Through two examples of VGI constructions in China, I depict types of networked publics involved in these processes. I show that the mutual constitution of networked publics and sociopolitical and technological transformations has produced new landscapes of civic engagement in China. I also show the limits and challenges of these VGI practices in this context. As such, this study contributes to the efforts of theorizing the geoweb through conceptualizing and foregrounding these new forms of social relations and interactions engaging with VGI practices, which in turn may entail new forms of knowledge production and politics.     

A microearthquake survey in the Abu-Simbel area in Egypt

From the middle of January to the middle of March, 1981 a microearthquake survey was conducted jointly by Polish and Egyptian seismologists in the Abu-Simbel area, about 230 km upstream from the Aswan High Dam. A small seismic array composed of six stations and a magnetic-tape digital recording system was operated during the survey. Altogether 63 microearthquakes at epicentral distances of up to 50 km and 12 local earthquakes at distances of up to 200 km were recorded, but only 16 microearthquakes could be properly located. All of them originated either directly under the High Dam Reservoir or close to its shores, thus implying their association with its water level fluctuations.It was deduced that under the Abu-Simbel array a deep fracture zone or deep fault extending in the NNE—SSW direction, 1–3 km wide and several kilometers deep, must be present to explain the observed effects of heavy attenuation and scattering of seismic waves under the array. This fracture zone might be a deep expression of the western edge of the Nile Valley in the Abu-Simbel area.     

A trust and reputation model for filtering and classifying knowledge about urban growth

In this paper we present a trust and reputation model to classify and filter collaboratively contributed geographic information. We hypothesize that users contribute information in a collaborative system akin to Web 2.0 collaborative applications. We build on previous work where trust is proposed as a proxy for information quality and propose a spatial trust model to filter and extract high quality information about urban growth behaviors contributed by users. The motivating scenario involves residents of recently urbanized areas taking into account their interactions with their surroundings. The main contribution of this paper is a formal trust and reputation model that takes into account the spatial context of users and their contributions.     

Effects of the October 25, 2010, Mentawai tsunami in La Réunion Island (France): observations and crisis management

On October 25, 2010, a Mw = 7.7 magnitude earthquake was recorded in the Kepulauan Mentawai archipelago, in Indonesia. Following the earthquake, the Pacific Tsunami Warning Center issued a tsunami bulletin to the countries of the Indian Ocean informing them that a local tsunami watch was in effect for Indonesia. La Réunion Island, a French territory located 5,000 km southwest of the seismic source, did not trigger its tsunami early warning protocol, but did suffer the impact of this tsunami 7h20 post-earthquake. This paper presents the post-tsunami survey conducted in La Réunion Island a few days after the event, providing run-up measurements that reach 1.72 m locally as well as information about the material losses and the crisis management. It provides a time sequence of the observations along the coast and the reactions of the population and authorities in dealing with this crisis. This paper also shows the local authorities’ lack of action in managing this event—thus increasing human and material vulnerabilities—the consequences for victims and the impact on the credibility of the local early warning system. These results provide geophysicists with information to better describe the source of this tsunami through far-field inversion and provide local decision makers with a comprehensive assessment of the weaknesses of the local early warning system and protocols.     

海河流域地下水资源存储量综合评价问题的研究

将模糊物元模型与改进的层次分析法相结合,构建了地下水资源存储量评价模型,并将其应用到海河流域的五个典型区域——石家庄、唐山、沧州、衡水和天津的地下水资源存储量评价中,计算结果表明五个典型区域中石家庄水资源存储量相对最好,属于中等程度,天津和唐山地下水资源较贫乏,衡水和沧州地下水资源很贫乏。评价结果与相关资料显示的各区域地下水系统实际情况基本吻合,这验证了所选指标及所构建模型的合理性,可为其它区域的地下水资源存储量评价提供参考。     

地下水污染调查中水样无机组分检测质量控制体系 的建立和应用

实验室分析全过程的质量控制,其目的是将检测误差控制在容许限度内,以保证数据在给定的置信水平内达到质量要求。国土资源部天津矿产资源监督检测中心根据地质矿产行业标准DZ/T0130—2006《地质矿产实验室测试质量管理规范》、DD2008—01中国地质调查局标准《地下水污染调查评价规范》,并参照其他行业对水质分析质量控制要求,结合水质检测的具体情况,制定了适宜的地下水分析过程的质量控制体系,使实验室质量控制和质量管理具有良好的操作性和可行性,确保检测数据的可靠性。文章从5个方面提出地下水水质无机组分检测中质量控制方法,使水质无机组分的检测质量得到有效控制。     

Landslide risk perception: a case study in Southern Italy

Perceptions of risk are a key issue when seeking to develop systems, practices and policies to protect local populations. This is particularly evident when risk mitigation strategies involve non-structural measures such as relocation and warning systems which presuppose the active involvement of the communities in question. This study adopts an interdisciplinary approach to studying the perceptions, knowledge and opinions on landslide risk amongst residents in Sarno, a small town in Southern Italy which was hit by disastrous landslides on 5–6 May 1998. The paper presents the results of a survey conducted in the months of March, April and May 2013 using a purpose-designed questionnaire. The survey was conducted using face-to-face interviews with 100 residents, 60 of whom live inside the so-called “red zone”, a territory declared at high residual risk soon after the events of 1998. The questionnaire included questions relating to perceived risk exposure, trust in institutions responsible for risk management, evaluations of risk mitigation measures and the early-warning strategy. The results of the study clearly emerges, amongst other issues, that the organisms which are responsible for risk management in Sarno need to develop more effective communication strategies in order to transmit knowledge about the actions implemented to reduce landslide risk in the area.     

GIS-based groundwater spring potential assessment and mapping in the Birjand Township,southern Khorasan Province,Iran

Three statistical models—frequency ratio (FR), weights-of-evidence (WofE) and logistic regression (LR)—produced groundwater-spring potential maps for the Birjand Township, southern Khorasan Province, Iran. In total, 304 springs were identified in a field survey and mapped in a geographic information system (GIS), out of which 212 spring locations were randomly selected to be modeled and the remaining 92 were used for the model evaluation. The effective factors—slope angle, slope aspect, elevation, topographic wetness index (TWI), stream power index (SPI), slope length (LS), plan curvature, lithology, land use, and distance to river, road, fault—were derived from the spatial database. Using these effective factors, groundwater spring potential was calculated using the three models, and the results were plotted in ArcGIS. The receiver operating characteristic (ROC) curves were drawn for spring potential maps and the area under the curve (AUC) was computed. The final results indicated that the FR model (AUC?=?79.38 %) performed better than the WofE (AUC?=?75.69 %) and LR (AUC?=?63.71 %) models. Sensitivity and factor analyses concluded that the bivariate statistical index model (i.e. FR) can be used as a simple tool in the assessment of groundwater spring potential when a sufficient number of data are obtained.     

地下水污染调查中水样有机组分分析质量控制

根据《地质矿产实验室测试质量管理规范》的要求,为保证地下水污染调查中样品的准确测定,需采取质量控制方法。文章阐述了地下水样品的前处理和测定过程的质量控制措施,建立了地下水有机组分分析过程的质量控制流程,确保其检测数据达到规范所允许的范围。     

Chemical contamination, toxicity, and benthic community indices in sediments of the lower Miami River and adjoining portions of Biscayne Bay, Florida

A large-scale survey of sediment quality in Biscayne Bay, Florida, was conducted in 1995–1996 to characterize the relative degree, geographic patterns, and spatial extent of degraded sediment quality. Chemical analyses and multiple toxicity tests were performed on 226 surficial sediment samples collected over an area of 484 km² in greater Biscayne Bay, including saltwater reaches of several tributaries. Benthic samples were collected and analyzed at one-third of the locations. One or more chemical concentrations exceeded effects range median (ERM) values in 35 samples, representing an area of 5.4 km² (1.1% of the survey area). Highly toxic conditions in amphipod survival tests occurred in 24 of the samples, representing 62 km² (13% of the area). Highly significant results were more frequently observed in three sub-lethal tests: sea urchin fertilization (affecting 47% of the area), sea urchin embryological development (84% of the area), and microbial bioluminescence (51% of the area). The highest levels of chemical contamination (range in mean ERM quotients of 0.2 to 2.0, average 0.76) were observed in samples from the lower Miami River. The high degree of contamination in the river contrasted sharply with conditions in the bay, where chemical concentrations generally were much lower (range in mean ERM quotients of 0.005 to 0.21, average 0.04). Amphipod survival tests showed a very high degree of correspondence with a gradient in chemical contamination in the river and adjoining reaches of the bay. Correlation analyses, scatter plots, and principal component analyses indicated that both amphipod survival in the laboratory tests and the abundance and diversity of the benthos decreased sharply with increasing concentrations of mixtures of organic compounds and trace metals in the sediments. The triad of analyses provided a strong weight of evidence of pollution-induced degradation of sediment quality in the riverine locations.