A modified binary space partitioning tree for geographic information systems

We present a reactive data structure, that is, a spatial data structure with detail levels. The two properties, spatial organization and detail levels, are the basis for a geographic information system (GIS) with a multi-scale database. A reactive data structure is a novel type of data structure catering to multiple detail levels with rapid responses to spatial queries. It is presented here as a modification of the binary space partitioning tree that includes the levels of detail. This tree is one of the few spatial data structures that does not organize space in a rectangular manner. A prototype system has been implemented. An important result of this implementation is that it shows that binary space partitioning trees of real maps have O(n) storage space complexity in contrast to the theoretical worst case O(n² ), with n the number of line segments in the map.     

Combining conventional and volunteered geographic information to identify and model forest recreational resources

It is now common for researchers in natural resource management and economics to develop spatial models of recreation demand for the purposes of valuation and planning. Such an approach has significant advantages but requires access to relatively detailed spatial data. In the absence of official data concerning resources, researchers may benefit from employing increasingly available volunteered geographic information (VGI) as a central source of data or to complement more traditional data sources. This paper describes the development of a map of forest recreational resources in Ireland by combining conventional forest cover data and VGI of recreational trails. As an extension the new map is combined with household survey data to explore respondent's ability to identify local recreational forests and models the impact of the characteristics of the closest forest on their annual visitation. The results suggest that VGI can be a useful resource to researchers in both the identification and characterisation of recreational resources. In addition, this paper finds that the distance to and characteristics of the nearest recreational forest has a significant impact on total annual visitation by members of the public.     

Performance evaluation and work-load estimation for geographic information systems

Abstract

Agencies acquiring GIS hardware and software are faced with uncertainty at two levels: over the degree to which the proposed system will perform the functions required, and over the degree to which it is capable of doing so within proposed production schedules. As the field matures the second concern is becoming more significant. A formal model of the process of acquiring a GIS is presented, based on the conceptual level of defining GIS sub-tasks. The appropriateness of the approach is illustrated using performance data from the Canada Land Data System. It is possible to construct reasonably accurate models of system resource utilization using simple predictors and least squares techniques, and a combination of inductive and deductive reasoning. The model has been implemented in an interactive package for MS-DOS systems.     

Usability evaluation for geographic information systems: a systematic literature review

The growing dissemination of geographic information systems (GIS) in recent years has increased the availability and use of geospatial tools. Despite this trend in GIS, usability is often not considered, and studies on usability are relatively rare. However, it has been shown that the effectiveness, efficiency and user satisfaction of these tools when used for geospatial tasks may be impacted by their design and terminology. In this article, we present a comprehensive review of the relevant literature. We analyze and compare publications of GIS usability evaluations, the methods that were used, and the findings reported. We thus produce a more detailed picture of GIS usability evaluations. Our contributions are (1) an overview of methods applied in case studies for evaluating the usability of GIS; (2) the identification of gaps and resulting weaknesses of previous studies; and (3) challenges and opportunities for future GIS usability studies. Our findings reveal a lack of usability guidelines for GIS, a lack of methods for analyzing complex workflows, and a lack of usage studies over longer periods of time. These contributions can help GIS developers and designers to improve the usability of their systems.     

Video support in teaching about geographic information systems: a review of six videotapes

Abstract

Abstract. The growing interest in teaching about geographic information systems (GIS) raises a number of issues concerning the effectiveness of conventional instructional methods. To convey basic GIS concepts and applications better requires much more emphasis upon visual media. One such medium is that of VHS (or Beta) videotapes. Six currently-available GIS-oriented videotapes are reviewed for this purpose. Their contents are summarized and an evaluation is made of the usefulness of each in classroom-based GIS instruction.     

An evaluation of crowdsourced information for assessing the visitation and perceived importance of protected areas

Parks and protected areas provide a wide range of benefits, but methods to evaluate their importance to society are often ad hoc and limited. In this study, the quality of crowdsourced information from Public Participation GIS (PPGIS) and Volunteered Geographic Information (VGI) sources (Flickr, OpenStreetMap (OSM), and Wikipedia) was compared with visitor counts that are presumed to reflect social importance. Using the state of Victoria, Australia as a case study, secondary crowdsourced VGI data, primary crowdsourced (PPGIS data) and visitor statistics were examined for their correspondence and differences, and to identify spatial patterns in park popularity. Data completeness—the percent of protected areas with data—varied between sources, being highest for OSM (90%), followed by Flickr (41%), PPGIS (24%), visitation counts (5%), and Wikipedia articles (4%). Statistically significant correlations were found between all five measures of popularity for protected areas. Using stepwise multiple linear regression, the explained variability in visitor numbers was greater than 70%, with PPGIS, Flickr and OSM having the largest standardized coefficients. The social importance of protected areas varied as a function of accessibility and the types of values (direct or indirect use) expressed for the areas. Crowdsourced data may provide an alternative to visitor counts for assessing protected area social importance and spatial variability of visitation. However, crowdsourced data appears to be an unreliable proxy for the full range of values and importance of protected areas, especially for non-use values such as biological conservation.     

Requirements and principles for the implementation and construction of large-scale geographic information systems

Abstract

This paper provides a brief survey of the history, structure and functions of ‘traditional’ geographic information systems (GIS), and then suggests a set of requirements that large-scale GIS should satisfy, together with a set of principles for their satisfaction. These principles, which include the systematic application of techniques from several sub-fields of computer science to the design and implementation of GIS and the integration of techniques from computer vision and image processing into standard GIS technology, are discussed in some detail. In particular, the paper provides a detailed discussion of questions relating to appropriate data models, data structures and computational procedures for the efficient storage, retrieval and analysis of spatially-indexed data.     

OutDet: an algorithm for extracting the outer surfaces of building information models for integration with geographic information systems

The integration of Building Information Modelling (BIM) and geographic information systems (GIS) is a promising but challenging topic to solve problems in construction industry. However, loading and rendering rich BIM geometric data and large-scale GIS spatial information in a unified system is still technologically challenging. Current efforts mainly simplify the geometry in BIM models, or convert BIM geometric data to a lower level of detail (LOD). By noticing that only exterior features of BIM models are visible from outdoor observation points, culling BIM interior facilities can dramatically reduce the computational burden when visualizing BIM models in GIS. This study explores the outline detection problem and presents the OutDet algorithm, which selects representative observation points, transforms & projects the BIM geometric data into the same coordinate system, and detects the visible facilities. Empirical study results show that OutDet can cull a large portion of unnecessary features when rendering BIM models in GIS. The use of outlines of BIM models is not an alternative but rather a supplementary approach for current solutions. Jointly using LOD and outer surface can help improve the efficiency of integrated BIM-GIS visualization.Because OutDet retains BIM geometry and semantics, it can be applied to more BIM-GIS applications..     

Reduction of disparities in access to green spaces: Their geographic insertion and recreational functions matter

Green spaces (GS) have many functions that can moderate the climate change impact and help prevent disease and thus alleviate public health expenses in a context of aging societies. However, several socioeconomic, demographic and geographic processes may render the access to GS challenging. Moreover, it is often critical to know what type of GS service to develop at a specific place. Also, measurements accuracy issues could be critical for planning and decision making. As an example of what could happen in many other cities of different sizes, we modeled and compared the access to GS, including several of their specific functions, in the Census Metropolitan Areas (CMA) of Montreal and Quebec City in Canada. We used the Quebec Integrated Chronic Disease Surveillance System (QICDSS) (average of 3 million people per year over 1996–2011) to measure over time, the proximity of each individual to the closest GS boundary using travel costs and spatial interaction models. ANOVA models and their corresponding base regressions were used to evaluate the statistical significance of the relationship of GS distances and surface to density, deprivation, gender and age, including interaction terms. The spatial clustering of the reduction of distances to GS was evaluated on a chronological basis. Unlike the larger CMA of Montreal, Québec City CMA showed greater equity in access to GS, largely due to the specific geographic insertion of linear GS. The CMA of Montreal showed an improvement in the access to GS which benefits the wealthy in the densest areas on the island of Montreal. Everything happens as if a green gentrification process affects the access to GS in Montreal. Our results suggest that for the promotion of GS as an important element of primary prevention in public health, both the quality or functions of GS and the geographic determinants of their access are of higher importance than a simple consideration of total GS surface per capita as often used by decision makers or public health promoters. They also underline the limits of standard measurements of attraction and accessibility and the complexity for large cities to promote environmental justice, given the complexity of their socio-demographic processes.     

Combining geographic information systems and ethnography to better understand and plan ocean space use

Agencies in the US with oversight for marine renewable energy development idealistically have sought space where this new use might proceed unhindered by other uses. Despite experiential evidence of spatial overlap among existing ocean uses, a lack of documentation made the identification of potential space-use conflicts, communication between existing and potential ocean users, and the design of mitigation exceedingly challenging.We conducted a study along the US Atlantic and Pacific coasts to gather and document available spatial information on existing use through a compilation and organization of geographic information system (GIS) data. Stakeholder group meetings were used to vet the collected spatial data, and ethnographic interviews were conducted to gather knowledge and cultural perspectives. Results show extensive coverage and overlap of existing ocean space uses and provide a visualization of the social and cultural landscape of the ocean that managers can use to determine which stakeholders to engage.Marine resource managers are encouraged to recognize that marine space use is dynamic and multi-dimensional and as such research thereof requires a balance between the efficiency of GIS and the stories captured and told by ethnographic research. There are important linkages within and across fisheries and other uses, communities and interests, and across the land–sea interface. Therefore, it is important to use techniques demonstrated in this research that (1) integrate ethnographic and geospatial data collection and analysis; (2) engage stakeholders throughout the process; and (3) recognize the unique qualities of each geographic location and user group to support sound decision-making.     

The development and applications of geographic information systems for urban and regional planning in the developing countries

Abstract

In the past 10 years, geographic information systems (GIS) have been widely used in urban and regional planning in the developed countries in Australia, North America and Europe. However, the use of GIS in urban and regional planning in the developing countries is limited and still at an early stage of development. This paper examines the current use of GIS in urban and regional planning in the developing countries in Asia. The major hindrances in the use of GIS in the developing countries is related not so much to the technology of GIS but more to data availability, leadership, organization structure and planning practice. For GIS to be more useful to urban and regional planning in the developing countries the development of a sustainable strategy in developing GIS and staff training is needed. International assistance agencies and GIS software companies can play an active role in making GIS available and usable to the planners in the developing countries.     

Volunteered geographic information quality assessment using trust and reputation modelling in land administration systems in developing countries

This article presents an innovative approach to establish the quality and credibility of Volunteered Geographic Information (VGI) such that it can be considered in Land Administration Systems (LAS) on a Fit for Purpose (FFP) basis. A participatory land information system can provide affordable and timely FFP information about land and its resources. However, the establishment of such a system involves more than just technical solutions and administrative procedures: many social, economic and political aspects must be considered. Innovative approaches like VGI can help address the lack of accurate, reliable and FFP land information for LAS, but integration of such sources relies on the quality and credibility of VGI. Verifying volunteer efforts can be difficult without reference to ground truth: a novel Trust and Reputation Modelling methodology is proposed as a suitable technique to effect such VGI data set validation. This method has been applied to successfully demonstrate that VGI can produce accurate and reliable data sets which can be used to conduct regular systematic updates of geographic information in official systems. It relies on a view that the public can police themselves in establishing proxy measures of VGI quality thus facilitating VGI to be used on a FFP basis in LAS.     

Spatial distribution characteristics of national protected areas in China

Journal of Geographical Sciences - This paper investigated spatial structures of 3418 national protected areas (NPAs) grouped into 13 types using GIS and quantitative analysis, including point...     

Spatio-temporal analysis of the human footprint in South Ecuador: Influence of human pressure on ecosystems and effectiveness of protected areas

Human influence and its impacts are perceptible in all ecosystems resulting in land transformation, changes in global biogeochemistry, climate change, and loss of biological diversity. Mapping the spatial and temporal patterns of human influence is essential to address land use management and conservation programs. In this study, we tailored the Human Footprint index (HF) developed at global level to evaluate the spatial and temporal patterns of human pressure in South Ecuador for 1982, 1990 and 2008. Landscape and ecosystem levels were analyzed to identify the contribution of different human proxies to the HF. We also used the HF to evaluate the effectiveness of protected areas to reduce human pressure in the surrounding landscape. We found that levels of human pressure increased and the wildest areas decreased since 1982. We identified important “hotspots of changes” in the seasonally dry forests in the western part and the premontane evergreen forest in the eastern part of the study area. Our results show that each human proxy contributes in a different way to the observed values of HF in the studied ecosystems. Finally, we found that Podocarpus NP, the most important protected area in our study region, seems to be partially effective in reducing human pressure inside and in the buffer zones where only a low increase in HF was detected. However, the HF values observed in the surrounding landscape were higher than those observed in the buffer zone and inside the protected area. We demonstrated that HF could be a useful regional evaluation tool to facilitate conservation planning.     

Vague cognitive regions in geography and geographic information science

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.     

中国自然保护地旅游资源利用的冲突和协调路径分析

协调旅游资源保护与利用冲突是当前自然保护地体系建设亟待解决的关键问题之一。论文利用质性研究方法,在系统总结中国自然保护地旅游资源利用的阶段特征与模式基础上,分析了现阶段旅游资源利用的冲突及其矛盾本质,并从多维视角探讨冲突的形成机制,从生态保护、社区发展、理论逻辑等方面分析现阶段自然保护地旅游资源利用的可行性与合理性;最后从建立利益主体权责明确的一体化资源利用机制、加强对旅游资源利用活动资源环境效应的评估、因地制宜探索自然生态资源保护和利用的动态模式、建立更加精准化的自然保护地分区利用方案、以生态理念为指导创新生态旅游产品类型等方面,提出自然保护地旅游资源利用的合理路径。研究结论有助于各界从系统性视角深入理解现阶段自然保护地旅游资源利用的冲突,同时对合理推动自然生态资源的可持续利用具有借鉴意义。     

Developing geographic information infrastructures: the role of access policies

Within societies, information availability is a key issue affecting society's well‐being. For geographic information, a geographic information infrastructure (GII) facilitates availability and access to geographic information for all levels of government, the commercial sector, the non‐profit sector, academia, and ordinary citizens. Although the importance of access policies in the development of a GII is commonly understood, research that has assessed the impact of access policies on this development is scant. This article adds this perspective. Based on information acquired from case‐study and literature research, the author argues that open‐access policies do not always promote GII development and in specific instances are counter‐productive. These findings may explain why many nations still adhere to cost‐recovery policies instead of following access policies recommended by research. The article provides alternatives for changing current policies into new access policies that promote GII development.     

A simple method for estimating basin-scale groundwater discharge by vegetation in the basin and range province of Arizona using remote sensing information and geographic information systems

Groundwater is a vital water resource in the arid to semi-arid southwestern United States. Accurate accounting of inflows to and outflows from the groundwater system is necessary to effectively manage this shared resource, including the important outflow component of groundwater discharge by vegetation. A simple method for estimating basin-scale groundwater discharge by vegetation is presented that uses remote sensing data from satellites, geographic information systems (GIS) land cover and stream location information, and a regression equation developed within the Southern Arizona study area relating the Enhanced Vegetation Index from the MODIS sensors on the Terra satellite to measured evapotranspiration. Results computed for 16-day composited satellite passes over the study area during the 2000 through 2007 time period demonstrate a sinusoidal pattern of annual groundwater discharge by vegetation with median values ranging from around 0.3 mm per day in the cooler winter months to around 1.5 mm per day during summer. Maximum estimated annual volume of groundwater discharge by vegetation was between 1.4 and 1.9 billion m³ per year with an annual average of 1.6 billion m³. A simplified accounting of the contribution of precipitation to vegetation greenness was developed whereby monthly precipitation data were subtracted from computed vegetation discharge values, resulting in estimates of minimum groundwater discharge by vegetation. Basin-scale estimates of minimum and maximum groundwater discharge by vegetation produced by this simple method are useful bounding values for groundwater budgets and groundwater flow models, and the method may be applicable to other areas with similar vegetation types.     

多源地理大数据支撑下的地理事件建模与分析

地理事件作为描述地理过程的基本单元,逐渐成为地理信息科学（GIS）核心研究内容。由于受人类活动数据获取限制,GIS对地理事件的建模和分析主要关注事件所引起的地理空间要素变化及要素之间的相互影响与作用机制。然而,近年来随着基于位置服务数据（LBS）爆炸式的增长和人类活动大数据定量刻画手段的快速发展,地理事件对人类活动的影响以及公众对地理事件的网络参与度都引起了多个领域的广泛关注,对地理事件的时空认知、建模方法和分析框架提出了巨大的挑战。对此,本文首先深入分析了大数据时代地理事件的概念与分类体系;其次,基于地理事件的时空语义给出了基于图模型的事件数据建模,建立了事件本体及其次生或级联事件的“节点—边”表达结构,开展了事件自身时空演化及其前“因”后“果”的形式化描述;第三,从时空数据分析与挖掘的角度,给出了大数据时代地理事件建模与分析的整体框架,拟突破传统“地理实体空间”事件探测与分析方法的局限性,融合“虚拟空间”事件发现与传播模拟思路,实现多源地理大数据支撑下的面向地理事件的人类活动多尺度时空响应与区域差异分析;最后,本文以城市暴雨事件为例诠释了本文所提出的地理事件建模与分析方法,从城市和城市内部两个尺度进行了暴雨事件与人类活动的一致性响应及区域差异分析,得到了明确的结论,验证了前文分析框架的可行性与实用性。