Vineyard site suitability analysis by use of multicriteria approach applied on geo-spatial data

Abstract

In this research, multicriteria decision analysis with pairwise comparison weighting method was utilized to determine the suitable locations for vineyard plantation in Sarkoy region of Turkey. Soil maps, meteorological measurements, slope, aspect and elevation maps were used as input to conduct spatial analysis. Different methods were compared and pairwise comparison method was identified as the most appropriate method of weighting for this spatial analysis. Current vineyard areas were determined using Worldview-2 imagery and their spatial distribution compared with the resulting suitability map to determine the current suitability. Comparisons showed current vineyards were mostly established in locations where suitability map expresses low capability. Further inspection unveiled that, these low capability lands are closer to the transportation networks and city/county centres that tend to be in sea level elevations as opposed to vine grapes thriving in higher altitudes. Results also enabled providing suggestions on alternative sites for new vineyard plantation.     

How do people perceive the disclosure risk of maps? Examining the perceived disclosure risk of maps and its implications for geoprivacy protection

ABSTRACT

This research examines how people subjectively perceive the disclosure risk of a map using original data collected in an online survey with 856 participants. The results indicate that perceived disclosure risk increases as the amount of locational information displayed on a map increases. Compared to point-based maps, perceived disclosure risk is significantly lower for kernel density maps, convex hull maps, and standard deviational ellipse maps. The results also revealed that perceived disclosure risk is affected by map scale and the presence of information of other people on a map. For geomasking methods, perceived disclosure risk decreases as aggregation level increases and as relocation distance increases. However, aggregation methods (point to polygon) are more effective in preventing the re-identification of individuals when compared to relocation methods (point to point). Lastly, the perceived disclosure risk of a map that displays socially-vulnerable people is significantly higher than that of a map that displays non-vulnerable groups. Specifically, a map displaying the private locations of elementary school students has the highest perceived disclosure risk. Based on the results, a set of geoprivacy protection guidelines for mapping people’s private locations to minimize people’s perceived disclosure risk is proposed. Implications for mapping infectious diseases like the COVID-19 are also discussed.     

Web Cartography in the United States

Over the recent years, spatial data have become more accessible to members of the public, and there is an increased awareness that spatial data are an essential ingredient in the development of governance policies. In parallel, computing devices that can render real-time 3D environments in nearly photo-realistic quality have become a common household item. Integrating spatial data and virtual environments opens the possibility of presenting spatial data in a highly visual way—the same way we experience our everyday world. We have developed a landscape planning tool called SIEVE (Spatial Information and Visualization Environment), which allows users to explore existing spatial data and hypothetical future scenarios in a real-time 3D environment, links to environmental process models outcomes, and also provides a collaborative decision-making environment. SIEVE has an automatic model-building component that allows users to select a region on a 2D map using a web portal and to download automatically generated 3D landscape environments. SIEVE not only models above-ground features but also incorporates underground features. This allows users to see the connection between below- and above-ground processes. Lastly, SIEVE incorporates a multi-user environment that allows users from different locations to gather in the virtual landscapes for exploring and decision-making purposes.     

Improvement of a location-aware recommender system using volunteered geographic information

Abstract

Recommender systems (RS), as supportive tools, filter information from a massive amount of data based on the determined preferences. Most of the RS require information about the context of users such as their locations. In such cases, location-aware recommender systems (LARS) can be employed to suggest more personalized items to the users. The most current research projects on LARS focus on the development of algorithms, evaluation methods and applications. However, the role of up-to-date spatial databases in LARS is not a well-researched area. The up-to-date spatial information would potentially improve the accuracy of items which are recommended by LARS. Volunteered geographic information (VGI) could be a low-cost source of up-to-date spatial information for LARS. This article proposes an approach to enrich spatial databases of LARS by VGI. Since not all records of VGI are fitted for use in LARS, a mechanism is developed to identify useful information. Some VGI data sets refer to existing spatial data in the database while other VGI data sets are shared for the first time. Therefore, the proposed method assessed the quality of VGI with reference source (for VGI which is existed in the database) and VGI without reference source (for VGI which is shared for the first time). To demonstrate the feasibility of the proposed approach, a mobile application has been developed to recommend suitable restaurants to the users based on their geospatial locations. The evaluation of the method indicates that VGI can potentially enhance the functionality of the LARS in predicting the users’ interests.     

Objective and Subjective Comparison in Choroplethic Mapping

Abstract

Visual map comparison can supplement statistical analysis by providing information as to where and how spatial correspondence occurs. The associations that may be discovered are influenced by the nature of the map features being compared and the criteria used for making the comparisons. In this paper the author has tried to identify the elements of visual recognition that map readers use to associate or differentiate geographical distributions represented by choropleth maps. The main components of the multivariate map reading process are pointed out, including the perceptual interactions between the actual locations of map tones and the overall similarity between map patterns.     

Recent Maps and Atlases — Map Cabinet

Abstract

There is currently a high demand for spatial data usage within web applications. From a technical viewpoint, web services and geoportals aim to fulfil user requirements; however, the current cartographic methods do not satisfy the needs of the end users. The problem is more challenging when the final map contains data from various sources that have various cartographic characteristics; therefore, the vital information might be located under the base map layer. In this paper, we propose the concept of layer priorities as foreground, middle ground or background, and we propose the two following methods to enhance the symbolisation: polygon overlay and colour saturation methods. The results from two case studies show that these methods can satisfy the requirements of the end users.     

Using Sound to Represent Positional Accuracy of Address Locations

Abstract

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Uncertainty data are often ignored by spatial data users for reasons that include difficulty of representation and comprehension. This study evaluated the benefits of a sonification extension to ArcGIS which represented the positional accuracy of address locations using piano notes. The approach was assessed by 49 survey participants via a computer-based task and subsequent discussion. Two factors that influenced successful interpretation were the proportion of values requiring detection and the presentation method. Knowledge of the data source also appeared relevant. Future studies will examine applications to climate scenarios and visualisations of future landscapes, as well as other aspects of sound.     

Sonic Maps for Hiking—Use of Sound in Enhancing the Map Use Experience

Abstract

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The use of soundscapes on digital maps in order to enrich our experience of the map use has been recognized as a part of other multimedia components in several previous research projects. The study described in this paper was conducted as part of ongoing research projects aiming to develop mobile and web applications for outdoor activities. The research describes the aims of finding new kinds of ways of communicating spatial information, even to those who are visually impaired, and, in general, to provide map users with a profounder use experience. The paper reviews previous studies and describes the sonic map implementations accomplished to date. The implementation examples presented cover a hiking use case in a national park. Sonic maps can help the users to plan their hike in advance and further provide those who are not able to visit the park with a multimodal experience of the atmosphere. Finally, conclusions are given and possible improvements for the future are discussed.     

GIS and simple systems for visual,interactive, spatial analysis

Abstract

In much the same way as a spreadsheet is more appropriate to some needs than a fully relational DBMS, many users interested in analysis of spatially referenced data have fairly unsophisticated requirements for extensive data storage or complex retrieval functions, and limited needs for topographic detail, cartographic accuracy or advanced map editing; however, they do require access to a wide range of statistical functions for data transformation, reduction and smoothing, multivariate analysis, and the modelling of spatial relationships. This paper argues that the needs of such users are poorly met by the 'mainstream' model for GIS that is often presented in the literature. A PC-based system, equivalent in GIS terms to the spreadsheet, is described. It integrates simple data structures, limited map creation and editing, a powerful range of standard and spatially orientated statistical functions, and the ability to interactively present results through chloropleth, contour, proportionate symbol, or proximally shaded maps. It is particularly designed to be easily accessible and to encourage visual interactive analysis. For some users such a system has acted as an adequate solution in its own right and for others it has provided a useful educational transition to more extensive and powerful systems.     

Point grid map: a new type of thematic map for statistical data associated with geographic points

ABSTRACT

Social, economic, and environmental statistical data associated with geographic points are currently globally available in large amounts. When conventional thematic maps, such as proportional symbol maps or point diagram maps, are used to represent these data, the maps appear cluttered if the point data volumes are relatively large or cover a relatively dense region. To overcome these limitations, we propose a new type of thematic map for statistical data associated with geographic points: the point grid map. In a point grid map, an input point data set is transformed into a grid in which each point is represented by a square grid cell of equal size while preserving the relative position of each point, which leads to a clear and uncluttered appearance, and the grid cells can be shaded or patterned with symbols or diagrams according to the attributes of the points. We present an algorithm to construct a point grid map and test it with several simulated and real data sets. Furthermore, we present some variants of the point grid map.     

Harveys and Walking Maps

Abstract

Geographical information is connected to everyday life in many ways. Web cartography has made geospatial data more available to the public. In the next few years, the average age of the population will be over 51 years, with more than 15% of the population over the age of 65 years. The fact that the senior population is increasing suggests that online mapping and map viewer design should be aware of the senior population’s visual restrictions, as well as restrictions of other potential map users, including colour-vision-impaired users. This paper describes the senior population’s visual restrictions that can be compared with colour-vision-impaired users and provides guidelines with regard to online mapping and map viewer design for this growing segment of the elderly population.     

Exploring differences of visual attention in pedestrian navigation when using 2D maps and 3D geo-browsers

ABSTRACT

Despite the now-ubiquitous two-dimensional (2D) electronic maps, three-dimensional (3D) globe viewers, or 3D geo-browsers such as Google Earth and NASA World Wind have gained much attention. However, the effect of such interactive 3D geo-browsers on spatial knowledge acquisition and decision-making is not well known. This study aims to explore the potential benefits of using interactive 3D geo-browsers in three processes of pedestrian navigation (self-localization, spatial knowledge acquisition, and decision-making) in digital environments. We employed eye tracking to show differences of visual attention in pedestrian navigation between a 2D map (Google Map) and a 3D geo-browser (Google Earth). The results indicated that benefits and drawbacks of 3D representations are task dependent. Participants using the 3D geo-browser had an extensively visual search resulting in significantly longer response time than the 2D participants for spatial knowledge acquisition, whereas 3D users performed a more efficient visual search and resulted in a better navigation performance at complex decision points. We speculate that the inefficient knowledge acquisition when using the 3D geo-browser was most probably due to information overload and obstructed views. Landmarks in photorealistic 3D models assisted recall of spatial knowledge from mental maps, which contributed to efficient decision-making at a complex turning point. These empirical results can be helpful to improve the usability of pedestrian navigation systems.     

Automation and Democratization of Cartography: An Example of a Mapping System at CEM,University of Durham

Abstract

Over the last three decades, the information revolution and technological advances have led to a paradigm shift in cartography. Recently, the major emphasis has been on 'democratization of cartography', where individuals can be empowered with electronic tools to analyse and visualize spatially referenced data (Morrison, 1994). But, an ordinary user can not effectively use the available GIS tools to visualize geographical data. Therefore, cartographers and/or GIS experts need to develop user-friendly map making systems to facilitate the democratization of cartography. A mapping system was designed using the advanced macro language (AML) and menus of ARC/INFO at the Curriculum for Evaluation and Management Centre (CEM) in Durham University to automate the mapping process (extending from spatial and non-spatial data extraction to the printing of a final map), so that any user can map pupils' locations of any school in the United Kingdom simply by entering some key information. The procedure followed to automate pupils' mapping is described in this paper. A similar programming approach can be helpful to automate mapping systems in a local network and on web.     

Seven possible states of geospatial data with respect to map projection and definition: a novel pedagogical device for GIS education

ABSTRACT

Conceptually, the theory and implementation of “map projection” in geographic information system (GIS) technology is difficult to comprehend for most introductory students and novice users. Compounding this difficulty is the concept of a “map projection file” that defines map projection parameters of geo-spatial data. The problem of the “missing projection file” appears ubiquitous for all users, especially in practice where data is widely shared. Another common problem is inadvertent misapplication of the “Define Projection” tool that can result in a GIS dataset with an incorrectly defined map projection file. GIS education should provide more guidance in differentiating the concepts of map projection versus projection files by increasing understanding and minimizing common errors. A novel pedagogical device is introduced in this paper: the seven possible states of GIS data with respect to map projection and definition. The seven possible states are: (1) a projected coordinate system (PCS) that is correctly defined, (2) a PCS that is incorrectly defined, (3) a PCS that is undefined, (4) a geographic coordinate system (GCS) that is correctly defined, (5) a GCS that is incorrectly defined, (6) a GCS that is undefined, and (7) a non-GCS. Recently created automated troubleshooting tools to determine a missing map projection file are discussed.     

Development of GIS-based environmental information system: an Indian scenario

Abstract

Ideally, scientists should be able to format, explore, analyse, and visualise data in a simple, powerful and fast application that would seamlessly integrate georeferenced data from a variety of data sources into an intuitive visualisation. The focus of an Environmental Information System is providing environmental information to decision makers, policy planners, scientists and engineers, research workers, etc. which ensures integration of data collection, collation, storage, retrieval and dissemination to all concerned. All such queries should be responded to supplying substantive information in the form of reports. The paper presents an innovative way to utilise the geographic information associated with the environmental data. The stand-alone application is the integration of using ArcObjects Environmental System Research Institute ArcGIS Engine 9.1 and VB.Net. The geographic information system (GIS)-based application, a framework of digital earth in terms of environmental information system provides a user-friendly query interface, which gives information about various environmental parameters in tabular as well as on map display. It also provides the visual interpretation to make further analysis and future decisions at multiple scales, locations and extents. The facility for modifying the map attributes and corresponding databases is integrated to update the information system. Output spatial data are produced in the form of reports using selected fields with display on map.     

Understanding demographic and socioeconomic biases of geotagged Twitter users at the county level

ABSTRACT

Massive social media data produced from microblog platforms provide a new data source for studying human dynamics at an unprecedented scale. Meanwhile, population bias in geotagged Twitter users is widely recognized. Understanding the demographic and socioeconomic biases of Twitter users is critical for making reliable inferences on the attitudes and behaviors of the population. However, the existing global models cannot capture the regional variations of the demographic and socioeconomic biases. To bridge the gap, we modeled the relationships between different demographic/socioeconomic factors and geotagged Twitter users for the whole contiguous United States, aiming to understand how the demographic and socioeconomic factors relate to the number of Twitter users at county level. To effectively identify the local Twitter users for each county of the United States, we integrate three commonly used methods and develop a query approach in a high-performance computing environment. The results demonstrate that we can not only identify how the demographic and socioeconomic factors relate to the number of Twitter users, but can also measure and map how the influence of these factors vary across counties.     

ColorBrewer.org: An Online Tool for Selecting Colour Schemes for Maps

Abstract

Choosing effective colour schemes for thematic maps is surprisingly difficult. ColorBrewer is an online tool designed to take some of the guesswork out of this process by helping users select appropriate colour schemes for their specific mapping needs by considering: the number of data classes; the nature of their data (matched with sequential, diverging and qualitative schemes); and the end-use environment for the map (e.g., CRT, LCD, printed, projected, photocopied). ColorBrewer contains 'learn more' tutorials to help guide users, prompts them to test-drive colour schemes as both map and legend, and provides output in five colour specification systems.     

Representing of contour lines by turning point preserving quadratic splines

Abstract

Terrain data obtained from satellite imagery or by scanning existing contour maps is in raster mode. Such data may be compressed by detecting and storing the critical points of contour lines. When hand digitising a contour map, a trained digitiser operator would usually select points which visually appear to be critical points. Existing interpolation techniques often fail to restore the critical points, including turning points, to their original positions. This article illustrates the use of splines composed of quadratic Bézier curves with monotone curvature for rendering contour lines which are represented only by their turning and end points, such that the positions of the turning points are preserved.     

Approach to calculating spatial similarity degrees of the same river basin networks on multi-scale maps

Obtaining spatial similarity degrees among the same objects on multi-scale maps is of importance in map generalization. This paper firstly defines the concepts of ‘map scale change’ and ‘spatial similarity degree’; then it proposes a model for calculating the spatial similarity degree between a river basin network at one scale and its generalized version at another scale. After this, it validates the new model and gets 16 points in the model validation process. The x-coordinate and y-coordinate of each point are map scale change and spatial similarity degree, respectively. Last, a formula for calculating spatial similarity degree taking map scale change as the only variable is obtained by the curve fitting method. The formula along with the model can be used to automate the algorithms for simplifying river basin networks.     

The First Ordnance Survey District Maps of England,Wales and Scotland 1857–1898

Abstract

The main goal of this research is to set a group of typographic criteria to suit a wide array of map users. A group of Bertin’s visual variables were applied individually and associatively for the same set of labels. Two kinds of maps (with point and areal objects) were presented to expert and non-expert map users and analysed accordingly. Additionally, the effect of gender variation was taken into account. The data were aggregated and studied for each graphical variable. For some combinations of Bertin’s variables, statistically significant differences were detected in the preferences of the different map users (e.g. male versus female and expert versus non-expert). Consequently, we identified which graphical variables (individually or combined) were more preferred by specific user groups in relation to their application on text objects.