共查询到20条相似文献，搜索用时 421 毫秒
1.
Daniel R. Montello Alinda Friedman Daniel W. Phillips 《International journal of geographical information science》2014,28(9):1802-1820
Cognitive regions are regions in the mind, reflecting informal ways individuals and cultural groups organize their understanding of earth landscapes. Cognitive region boundaries are typically substantially vague and their membership functions are substantially variable – the transition from outside to inside the region is imprecise or vague, and different places within the region are not equally strong or clear as exemplars of the region. Methods for assessing and cartographically depicting cognitive regions, as with other vague geographic regions, have traditionally implied an inappropriate level of boundary sharpness and membership uniformity, such as when boundaries are mapped as precise lines. Research in recent decades has explored methods for assessing and depicting boundary vagueness and membership variability, either within or across individuals, but has still assumed homogeneity and regularity in the vagueness and variability. In this article, we present two studies that assess the cognitive regions of ‘Northern’ and ‘Southern’ California, and, for comparison, ‘Northern’ and ‘Southern’ Alberta. The first study uses a standard boundary-drawing task; the second uses a novel task in which participants rate cells of a high-resolution grid laid over an outline map. This technique allows us to assess and depict vagueness and nonuniformity that is heterogeneous and irregular across different areas. Differences in the conceptualization of ‘Northern’ and ‘Southern’ regions in California, as compared to those in Alberta, point to thematic influences on cognitive regions in California but not in Alberta. As is often true with cognitive regions, Northern and Southern California are about attitude, not just latitude. 相似文献
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Thomas Bittner 《International journal of geographical information science》2013,27(5):825-850
For inherently vague and granular phenomena such as ecoregions, ecosystems, biomes, and biotopes, the interplay of granularity and vagueness leads to a trade-off in the classification and delineation of such phenomena: the goal of preciseness (lack of vagueness) of the delineation contradicts the goal of building a sophisticated classification system using the Aristotelian method of classification. This trade-off is based on the reliance on local qualities for a precise delineation of particular regions and the reliance on nonlocal qualities that serve as differentia in the Aristotelian classification. An ontological analysis of the logical interrelations between vagueness, granularity, and scale is critical for developing logically rigorous, nonlocal, and nonarbitrary classification and delineation systems for inherently vague and granular geographic phenomena. 相似文献
4.
This study investigates regions on cognitive maps and methods used to identify their boundaries. Subjects either drew regional boundaries on a map or decided in which region sample points were located. These methods produced similar results with differences associated more with regional boundaries than cores. The amount of time needed to make point decisions demonstrated the subjects' cognitive process and corroborated boundaries and cores for the cognitive regions. Differences among subjects' maps were greater when boundaries were drawn. 相似文献
5.
Zhangang Wang Zixing Wu Honggang Qu Xianghong Wang 《International journal of geographical information science》2019,33(1):99-133
Complex regions are composed of a finite number of simple regions, and are always defined by hierarchical representation methods. This article focuses on a unified method for computing n-intersection-based binary topological relations between complex regions based on hierarchical characteristics, using known topological relations between simple regions. The hierarchical representation of complex regions is defined as the recursive process of region decomposition using a context-free grammar. To distinguish multiple components of a region and whether the interior of a hole is a part of the inner exterior or the outer exterior, three region operators are proposed to describe the configuration of a region represented as a formal expression. Then, three corresponding 25-intersection (25I) based Boolean matrix operators are proposed to compute topological relations based on the relationships between decomposed regions. Herein, the invalid conditions of the operators are verified in detail, and the invalidities can be eliminated by either applying our definition of complex regions or with the inclusion of additional information. The proposed 25I-based operators, as shown in our cases, can be used as a ‘bridge’ to link different n-intersection models, and as a useful computation tool for analyzing topological relations between regions with specific configurations. 相似文献
6.
Multiple Regressive Pattern Recognition Technique (MRPRT) is an adapted approach for improved geologic resource estimation.
We developed and tested this approach for the Platinum (Pt) bearing region near Goodnews Bay, Alaska, which presents an example
of a complex depositional environment. We applied geospatial and pattern recognition methods to assess the spatial distribution
of offshore Pt in the Goodnews Bay area from point data collected by various agencies. We used the coefficient of correlation
(r) and the Nash–Sutcliffe efficiency (E) to quantitatively assess the degree of accuracy of the estimated Pt distribution. We split the study area, based on trend
analysis, into two regions: inside the Bay and outside the Bay. We could not obtain appreciable estimates from the geospatial
and pattern recognition methods. Using MRPRT, we were able to improve r from 0.57 to 0.93 and the E from 28.31 to 92.91 inside the Bay. We achieved improvement in r from 0.55 to 0.61 and E from 28.46 to 34.52 outside the Bay. The reasons for a non-significant improvement outside the Bay have been discussed. The
results indicate that the proposed MRPRT has wide application potential in georesource estimation where input data is often
scarce. 相似文献
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David C. Folch Seth E. Spielman 《International journal of geographical information science》2014,28(1):164-184
The identification of regions is both a computational and conceptual challenge. Even with growing computational power, regionalization algorithms must rely on heuristic approaches in order to find solutions. Therefore, the constraints and evaluation criteria that define a region must be translated into an algorithm that can efficiently and effectively navigate the solution space to find the best solution. One limitation of many existing regionalization algorithms is a requirement that the number of regions be selected a priori. The recently introduced max-p algorithm does not have this requirement, and thus the number of regions is an output of, not an input to, the algorithm. In this paper, we extend the max-p algorithm to allow for greater flexibility in the constraints available to define a feasible region, placing the focus squarely on the multidimensional characteristics of the region. We also modify technical aspects of the algorithm to provide greater flexibility in its ability to search the solution space. Using synthetic spatial and attribute data, we are able to show the algorithm’s broad ability to identify regions in maps of varying complexity. We also conduct a large-scale computational experiment to identify parameter settings that result in the greatest solution accuracy under various scenarios. The rules of thumb identified from the experiment produce maps that correctly assign areas to their ‘true’ region with 94% average accuracy, with nearly 50% of the simulations reaching 100% accuracy. 相似文献
10.
Sanjiang Li Weiming Liu 《International journal of geographical information science》2013,27(2):194-216
How to express and reason with cardinal directions between extended objects such as lines and regions is an important problem in qualitative spatial reasoning (QSR), a common subfield of geographical information science and Artificial Intelligence (AI). The direction relation matrix (DRM) model, proposed by Goyal and Egenhofer in 1997, is one very expressive relation model for this purpose. Unlike many other relation models in QSR, the set-theoretic converse of a DRM relation is not necessarily representable in DRM. Schneider et al. regard this as a serious shortcoming and propose, in their work published in ACM TODS (2012), the objects interaction matrix (OIM) model for modelling cardinal directions between complex regions. OIM is also a tiling-based model that consists of two phases: the tiling phase and the interpretation phase. Although it was claimed that OIM is a novel concept, we show that it is not so different from DRM if we represent the cardinal direction of two regions a and b by both the DRM of a to b and that of b to a. Under this natural assumption, we give methods for computing DRMs from OIMs and vice versa, and show that OIM is almost the same as DRM in the tiling phase, and becomes less precise after interpretation. Furthermore, exploiting the similarity between the two models, we prove that the consistency of a complete basic OIM network can be decided in cubic time. This answers an open problem raised by Schneider et al. regarding efficient algorithms for reasoning with OIM. 相似文献
11.
This paper uses Landsat TM images, GIS technology, Digital Elevation and Habitat Assessment Models to assess the habitat suitability of the endangered plant Tetraena mongolica in western Ordos Plateau of China by selecting terrain, soil, climate, and human activity factors as assessment indices. The results are as follows: natural factors such as climate and terrain are not restrictive factors for the survival and development of T. mongolica in the research region, whereas human activity causes habitat quality of T. mongolica to change intensively in quantity and distribution. The area of less suitable habitat increased by 23.87 km2 compared to potential habitat suitability. Thus, in some areas, human activity may be a key factor causing the endangerment of T. mongolica. There were obvious differences of potential and practical habitat suitability between different habitat regions in the study area. The habitat quality was better in Wujiamiao, Dishan and Qipanjing regions, and worse in Wuda and Qianlishan regions. 相似文献
12.
Markus Konkol Christian Kray Max Pfeiffer 《International journal of geographical information science》2019,33(2):408-429
Reproducibility is a cornerstone of science and thus for geographic research as well. However, studies in other disciplines such as biology have shown that published work is rarely reproducible. To assess the state of reproducibility, specifically computational reproducibility (i.e. rerunning the analysis of a paper using the original code), in geographic research, we asked geoscientists about this topic using three methods: a survey (n = 146), interviews (n = 9), and a focus group (n = 5). We asked participants about their understanding of open reproducible research (ORR), how much it is practiced, and what obstacles hinder ORR. We found that participants had different understandings of ORR and that there are several obstacles for authors and readers (e.g. effort, lack of openness). Then, in order to complement the subjective feedback from the participants, we tried to reproduce the results of papers that use spatial statistics to address problems in the geosciences. We selected 41 open access papers from Copernicus and Journal of Statistical Software and executed the R code. In doing so, we identified several technical issues and specific issues with the reproduced figures depicting the results. Based on these findings, we propose guidelines for authors to overcome the issues around reproducibility in the computational geosciences. 相似文献
13.
Glacier retreat is not only a symbol of temperature and precipitation change, but a dominating factor of glacial lake changes in alpine regions, which are of wide concern for high risk of potential outburst floods. Of all types of glacial lakes, moraine-dammed lakes may be the most dangerous to local residents in mountain regions. Thus, we monitored the dynamics of 12 moraine-dammed glacial lakes from 1974 to 2014 in the Poiqu River Basin of central west Himalayas, as well as their associated glaciers with a combination of remote sensing, topographic maps and digital elevation models (DEMs). Our results indicate that all monitored moraine-dammed glacial lakes have expanded by 7.46 km2 in total while the glaciers retreated by a total of 15.29 km2 correspondingly. Meteorological analysis indicates a warming and drying trend in the Nyalam region from 1974 to 2014, which accelerated glacier retreat and then augmented the supply of moraine-dammed glacial lakes from glacier melt. Lake volume and water depth changed from 1974 to 2014 which indicates that lakes Kangxico, Galongco, and Youmojanco have a high potential for outburst floods and in urgent need for continuous monitoring or artificial excavation to release water due to the quick increase in water depths and storage capacities. Lakes Jialongco and Cirenmaco, with outburst floods in 1981 and 2002, have a high potential risk for outburst floods because of rapid lake growth and steep slope gradients surrounding them. 相似文献
14.
泰山旅游环境承载力及其时空分异特征与利用强度研究 总被引：74，自引：5，他引：69
旅游环境承载力作为一种稀缺性非实物资源具有空间分异和时间变化规律;文章采取静态的模型研究方法,对泰山主景区的旅游环境承载力作出了系统测算,揭示了其时空分异规律,剖析了旅游环境承载力资源的利用强度,提出了旅游调控策略。 相似文献
15.
Hilde Eggermont Oliver Heiri James Russell Mathias Vuille Leen Audenaert Dirk Verschuren 《Journal of Paleolimnology》2010,43(3):413-435
Fossil assemblages of chironomid larvae (non-biting midges) preserved in lake sediments are well-established paleothermometers
in north-temperate and boreal regions, but their potential for temperature reconstruction in tropical regions has never before
been assessed. In this study, we surveyed sub-fossil chironomid assemblages in the surface sediments of 65 lakes and permanent
pools in southwestern Uganda (including the Rwenzori Mountains) and central and southern Kenya (including Mount Kenya) to
document the modern distribution of African chironomid communities along the regional temperature gradient covered by lakes
situated between 489 and 4,575 m above sea level (a.s.l). We then combined these faunal data with linked Surface-Water Temperature
(SWTemp: range 2.1–28.1°C) and Mean Annual Air Temperature (MATemp: range 1.1–24.9°C) data to develop inference models for
quantitative paleotemperature reconstruction. Here we compare and discuss the performance of models based on different numerical
techniques [weighted-averaging (WA), weighted-averaging partial-least-squares (WA-PLS) and a weighted modern analogue technique
(WMAT)], and on subsets of lakes with varying gradient lengths of temperature and other environmental variables. All inference
models calibrated against MATemp have a high coefficient of determination (
r\textjack2 r_{\text{jack}}^{2} = 0.81–0.97), low maximum bias (0.84–2.59°C), and low root-mean-squared error of prediction (RMSEP = 0.61–1.50°C). The statistical
power of SWTemp models is generally weaker (
r\textjack2 r_{\text{jack}}^{2} = 0.77–0.95; maximum bias 1.55–3.73°C; RMSEP = 1.39–1.98°C), likely because the surface-water temperature data are spot measurements
failing to catch significant daily and seasonal variation. Models based on calibration over the full temperature gradient
suffer slightly from the limited number of study sites at intermediate elevation (2,000–3,000 m), and from the presence of
morphologically indistinguishable but ecologically distinct taxa. Calibration confined to high-elevation sites (>3,000 m)
has poorer error statistics, but is less susceptible to biogeographical and taxonomic complexities. Our results compare favourably
with chironomid-based temperature inferences in temperate regions, indicating that chironomid-based temperature reconstruction
in tropical Africa can be achieved. 相似文献
16.
Mark L. Heinrichs Susan E. Wilson Ian R. Walker John P. Smol Rolf W. Mathewes Kenneth J. Hall 《International Journal of Salt Lake Research》1997,6(3):249-267
Salinity fluctuations in lakes of semi-arid regions have long been recognised as indicators of palaeoclimatic change, and
have provided a valuable line of evidence in palaeo-climatic reconstruction. In the present study, fossil remains of diatoms
and midges were used to reconstruct salinity changes at Mahoney Lake from the early postglacial, through the early, mid and
late Holocene. A transition from midges typical of a freshwater community (Protanypus, Sergentia, Heterotrissocladius, Cladopelma, Dicrotendipes) during the early postglacial, to those indicative of saline environments (Cricotopus/Orthocladius, Tanypus) occurred in the early Holocene. The midge-inferred salinity values reflected the shift from freshwater (0.031 g/L) immediately
after deglaciation, to saline water (2.4 to 55.2 g/L) in subsequent periods. A less saline period was found to have occurred
after 1000 yr BP, suggesting a cooler or wetter period. The diatom record indicates similar trends, with freshwater taxa (e.g.,Cyclotella bodanica var. aff.lemanica) dominating near the bottom of the core. Diatom-inferred salinities indicate that saline conditions (about 30 g/L) prevailed
throughout subsequent Holocene time, although relatively fresh conditions are indicated following deposition of the Mazama
Ash, and from about 1500 yr BP until the present day. Midge and diatom-inferred salinity reconstructions for Mahoney Lake
compare favorably with each other, and with climate trends inferred from earlier palynological evidence. The palaeosalinity
record thus contributes new data relevant to past climatic conditions, in a region where little data have previously been
collected. 相似文献
17.
《The Professional geographer》2012,64(1):109-120
To explore landscape properties using language, we analyzed the semantics and associated physical properties of four generic landscape terms through spatially located microtoponyms in the Swiss canton of St. Gallen. We applied quantitative methods to physical and etymological data to understand how four common generic terms (Wald, Holz, Riet, and Moos) were used in microtoponyms in the canton. We observe that the meaningful elements associated with those generic terms characterize general properties of landscape independent of the feature type as well as specific properties linked to the feature. Moreover, using a toponym taxonomy, we compared co-occurrences of different terms (e.g., those associated with spatial relationships or vegetation) for the four generic terms. Holz, which we argue is more associated with land use than land cover, was markedly different in naming patterns from the other three generic terms, and we suggest that this was driven by a distinction between nature and culture. We conclude that the act of naming natural features is influenced not only by properties of the referent but also by broader scale landscape patterns and cognitive associations with landscape terms. Key Words: ethnophysiography, landscape, language, microtoponyms. 相似文献
18.
Giuseppe Calignano Rune Dahl Fitjar Nina Hjertvikrem 《Norsk geografisk tidsskrift. Norwegian journal of geography》2019,73(1):65-78
ABSTRACTWith combined insights from evolutionary economic geography and transition studies, the article examines the engagement of different regions in Norway in the innovation networks created within the European Union’s environmental programmes. The aim is to explore the programmes’ potential for supporting green economy and economic restructuring through branching and new path creation. The authors assess which regions participate in the programmes, which international networks they build, and which organisations participate in different regions. They compare three regions with different restructuring needs and research capacity – the counties of Rogaland, Hordaland, and Sør-Trøndelag (now part of the county of Trøndelag). They find that overall, Norwegian organisations participate relatively frequently in the programmes, but private firms play a marginal role. Their partners are mainly in core EU regions. Regional participation in the programmes is a function of research capacity as well as oil dependence. The authors conclude that in research-oriented regions, research establishments tend to dominate participation, creating potential for restructuring mainly through path creation. In oil-dependent regions, private firms account for a higher share of participants, enhancing the potential for branching. As the former regions participate more, the programme can mainly stimulate path creation. 相似文献
19.
Abstract According to recent research, one of the most promising strategies for intraurban job growth lies promoting localized clusters that produce goods and services which are primarily sold within a single city, metropolitan area, or urban region. However, in order to design urban policies to create or reinforce local clusters, the first challenge is to measure in a reliable way the clustering tendencies of different kinds of economic units in intraurban space. The aim is to compare the similarities and differences in results obtained from two methods designed to measure global clustering tendencies (the planar and network K-functions) in terms of characterization, scale, and intensity of intraurban localization patterns for tertiary economic units in a Latin American metropolis. It is concluded that the network K-function is a more appropriate method for measuring agglomeration patterns, scale, and intensity at the intra-urban level. 相似文献
20.
The authors use a web crawler to retrieve all periodical articles from CNKI between the 1950s and 2016 and then parse the abstracts of 293368 articles about grassland deterioration by word segmentation, location matching and other methods. The authors also construct a research hot regions extraction model of grassland deterioration in China based on a comprehensive research hot regions index of toponyms and then analyze the spatial pattern and dynamic change in research hot regions of grassland deterioration in China. The research shows the following: (1) The spatial heterogeneity of grassland deterioration in China can be effectively described by a model of grassland deterioration based on the comprehensive research hot regions index. (2) The research hot regions of grassland deterioration are mainly distributed in most regions of Inner Mongolia, Xinjiang, Qinghai, Tibet, Gansu and other provinces. The northeastern region of Inner Mongolia (such as Hulunbeier) and the eastern region of Inner Mongolia (such as Xilin Gol, Chifeng and Wulanchabu) are significant hot regions in the study of grassland deterioration. (3) The number of high research hot regions increases from 81 in the 1950s to 99 in the 2000s; the area increases from 1.038 million km2 to 1.146 million km2. The degree of hot for grassland deterioration research in 197 counties showed an upward trend. This paper also discusses the relationship between the region of research hot regions and the region of grassland deterioration and then indicates the differences between them in time matching, space matching and concept matching. 相似文献