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211.
Data-driven GIScience shows a growing interest in making spatial information from large text data. In this paper, we quantify and thus evaluate the relation between text frequency and properties of the outer-text, geographic setting by comparing text frequencies of mountain names to the respective geomorphometric characteristics. We focus on some 2000 unique mountain names that appear some 50,000 times in a large compilation of texts on Swiss alpine history. The results on the full data set suggest only a weak relation: only 5–10% of the variation in the text frequency being explained by the respective geomorphometric characteristics. However, an analysis of multiple scales allows us to identify a Simpson’s Paradox. What appears to be ‘noise’ in the analysis of all mountains in the whole of Switzerland shows significant local signals. Small spatial extents, found all over Switzerland, can show considerably strong correlations between text frequency and spatial prominence, with up to 90% of the total variation explained. We argue that our findings have practical implications for data-driven GIScience. Retrieving meaningful spatial information from text might only be possible if the spatial scale of analysis reflects the spatial scale described in the input text documents.  相似文献   
212.
柴达木盐湖化工科学研究联合基金实施概况   总被引:1,自引:1,他引:0  
对2014~2017年国家自然科学基金委员会—青海省人民政府柴达木盐湖化工科学研究联合基金申报与资助项目进行分析,重点研究联合基金实施概况,指出实施成效及存在的问题,并提出解决相关问题的发展建议,通过对联合基金资助和实施结果进行探讨,不断总结经验,优化模式,更好地为柴达木盐湖化工科学研究联合基金创新发展提供制度保障和参考依据。  相似文献   
213.
Tim Forsyth 《Geoforum》2008,39(2):756-764
Piers Blaikie’s writings on political ecology in the 1980s represented a turning point in the generation of environmental knowledge for social justice. His writings since the 1980s demonstrated a further transition in the identification of social justice by replacing a Marxist and eco-catastrophist epistemology with approaches influenced by critical realism, post-structuralism and participatory development. Together, these works demonstrated an important engagement with the politics of how environmental explanations are made, and the mutual dependency of social values and environmental knowledge. Yet, today, the lessons of Blaikie’s work are often missed by analysts who ask what is essentially political or ecological about political ecology, or by those who argue that a critical approach to environmental knowledge should mean deconstruction alone. This paper reviews Blaikie’s work since the 1980s and focuses especially on the meaning of ‘politics’ within his approach to political ecology. The paper argues that Blaikie’s key contribution is not just in linking environmental knowledge and politics, but also in showing ways that environmental analysis and policy can be reframed towards addressing the problems of socially vulnerable people. This pragmatic co-production of environmental knowledge and social values offers a more constructive means of building socially just environmental policy than insisting politics or ecology exist independently of each other, or believing environmental interventions are futile in a post-Latourian world.  相似文献   
214.
ABSTRACT

When producing optimal routes through an environment, considering the incline of surfaces can be of great benefit in a number of use cases. For instance, steep segments need to be avoided for energy-efficient routes and for routes that are suitable for mobility-restricted people. Such incline information may be derived from digital elevation models (DEMs). However, the corresponding data capturing methods (e.g. airborne LiDAR, photogrammetry, and terrestrial surveying) are expensive. Current low-cost and open-licensed DEM (e.g. Shuttle Radar Topography Mission [SRTM] and Advanced Spaceborne Thermal Emission and Reflection Radiometer [ASTER]) generally do not have sufficient horizontal resolution or vertical accuracy, and lack a global coverage. Therefore, we have investigated an alternative low-cost approach which derives street incline values from GPS traces that have been voluntarily collected by the OpenStreetMap contributors. Despite the poor absolute accuracy of this data, the relative accuracy of traces seems to be sufficient enough to compute incline values with reasonable accuracy. A validation shows that the accuracy of incline values calculated from GPS traces slightly outperforms incline values derived from SRTM-1 DEM, though results depend on how many traces per street segment are used for computation.  相似文献   
215.
Health outcomes related to vegetable and fruit consumption are widely recognized in the literature. This study investigates how dietary intake is influenced by individual, social, and environmental factors in the Toronto Census Metropolitan Area. The analysis and findings are based on data from the Canadian Community Health Survey which provides self‐reported vegetable and fruit intake from 6,513 adults in 2009‐2010. Food environment measures were constructed from commercial databases using kernel density estimates and network drive times. Spatial and multivariable techniques were used to determine the associations between diet, the food environment, and other health and socioeconomic factors. Particular emphasis was given to understanding the interaction between the food environment and socioeconomic position. Unexpectedly, supermarket density was found to have an inverse association with vegetable and fruit intake. Interaction terms for individuals with low income and reduced mobility produced different responses in men and women, confirming that the influence of the food environment is not uniform for all subgroups.  相似文献   
216.
Observations of living organisms by citizen scientists that are reported to online portals are a valuable source of information. They are also a special kind of volunteered geographic information (VGI). VGI data have issues of completeness, which arise from biases caused by the opportunistic nature of the data collection process. We examined the completeness of bird species represented in citizen science observation data from eBird and iNaturalist in US National Parks (NPs). We used approaches for completeness estimation which were developed for data from OpenStreetMap, a crowdsourced map of the world. First, we used an extrinsic approach, comparing species lists from citizen science data with National Park Service lists. Second, we examined two intrinsic approaches using total observation numbers in NPs and the development of the number of new species being added to the data-set over time. Results from the extrinsic approach provided appropriate completeness estimations to evaluate the intrinsic approaches. We found that total observation numbers are a good estimator of species completeness of citizen science data from US NPs. There is also a close relationship between species completeness and the ratio of new species added to observation data vs. observation numbers in a given year.  相似文献   
217.
安宁  梁邦兴 《地理科学进展》2017,36(12):1463-1474
国家科学基金(国家自然科学基金和国家社会科学基金的统称)研究立项课题旨在探究重大现实问题以及学科前沿发展,在很大程度上反映了相关学科研究的进展和整体水平。通过分析近20年来中国国家自然科学基金和社会科学基金对政治地理相关议题的资助,以及受资助人在该时期对相关议题的科研情况,得出以下结论:①2011年以来,国内政治地理学逐渐被认可和关注,并呈现出以北京、广州、昆明和上海研究机构为辐射中心的地理特征;②国内政治地理研究重点为边境与边界、环境政治、领土(主权和安全)、行政区划和管治、尺度和空间、社会和文化政治等六大议题;③国内政治地理研究日渐与国际接轨,但行政区划和管治等是独特的研究。整体而言,随着国家科学基金对政治地理研究支持力度的加大,期望能瞄准国际研究前沿和国内需求,建构符合中国国情的政治地理学学科体系。  相似文献   
218.
在野外实地考察和大量文献资料分析研究的基础上,运用人地相关的思想,对河洛地区这个独特的地理单元的自然条件和人文要素如政治、经济、文化和军事之间的相互关系进行了探讨。  相似文献   
219.
A personal computer-based geographic information system (GIS) is used to develop a geographic expert system (GES) for mapping and evaluating volcanogenic massive sulfide (VMS) deposit potential. The GES consists of an inference network to represent expert knowledge, and a GIS to handle the spatial analysis and mapping. Evidence from input maps is propagated through the inference network, combining information by means of fuzzy logic and Bayesian updating to yield new maps showing evaluation of hypotheses. Maps of evidence and hypotheses are defined on a probability scale between 0 and 1. Evaluation of the final hypothesis results in a mineral potential map, and the various intermediate hypotheses can also be shown in map form.The inference net, with associated parameters for weighting evidence, is based on a VMS deposit model for the Chisel Lake deposit, a producing mine in the Early Protoerzoic Snow Lake greenstone belt of northwest Manitoba. The model is applied to a small area mapped at a scale of 1:15,840. The geological map, showing lithological and alteration units, provides the basic input to the model. Spatial proximity to contacts of various kinds are particularly important. Three types of evidence are considered: stratigraphic, heat source, and alteration. The final product is a map showing the relative favorability for VMS deposits. The model is implemented as aFortran program, interfaced with the GIS. The sensitivity of the model to changes in the parameters is evaluated by comparing predicted areas of elevated potential with the spatial distribution of known VMS occurrences.  相似文献   
220.
作者围绕14届国际土壤科学大会,介绍了国际土壤分类、土壤调查制图、世界土壤和土地数字化数据库、东亚土壤地理和土壤全球变化等方面研究的最新进展,指出我国应把土壤地理研究置于全球变化的总目标下,加强中国土壤系统分类的研究,开展1∶100万土壤—土地数字化数据库的工作、建立土壤地理信息系统以及防治土壤退化保证农业的持续发展。  相似文献   
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