Computer-assisted Cartography Research Articles

Constraint-Based Spatial Data Management for Cartographic Representation at Different Scales

This article elaborates on map-quality evaluation and assessment as a result of the generalization of geospatial data through the development of a methodology, which incorporates a quality data model including constraints. These constraints are used to guide the generalization process and they operate as requirements in quality controls applied for the quality evaluation and assessment of the resulting cartographic data. The quality model stores the required map specifications compiled as constraints, and provides quality measures along with new techniques for the evaluation and assessment of cartographic data quality. This secures the map composition process in each and every step and for all features involved, at any map scale. The methodology developed results in the creation of a scale-dependent cartographic database that contains exclusively the features to be portrayed on the map, generalized properly according to the map scale. It will reduce cartographers’ need to review each transformation throughout the map-composition process with considerable savings in time and money and, on the other hand, it will secure the quality of the final map. The formulation of the proposed methodology amalgamates generalization theory with the authors’ research in computer-assisted cartography, taking into account the work conducted on the topic by other researchers. In this study, the quality requirements, the measures and the associated techniques together with the results of the application of the proposed methodology for area and line features are described in detail to allow others to replicate and build on the presented results.

Henri de Navarre et le Midi atlantique français. Histoire d’une itinérance (1570-1589)

Henri of Navarre’s itinerary between (1570-1589) is well known, but his study, thanks to a database and computer-assisted cartography, opens up a series of research into itineraries, at defined periods, in a variety of contexts. The cross-referencing of this cartography with that of the printing places, and sites of musical, poetic or theatrical performances remains to be done. It opens the possibility of proposing in the near future a “Route Henri de Navarre” in New Aquitaine.

Participatory Maps

There has recently been considerable attention paid to spatial visualizations in data journalism; less as a product and more as practice. This refers to the notion that rather than reading maps as fixed representations, digital mapping is by nature a dynamic, performative, and participatory practice. In particular, mapping environmental damage, endangered species, and human-made disasters has become one focal point for environmental knowledge production. This type of digital map has been highlighted as a processual turn in critical cartography, whereas in related computational journalism, it can be seen as an interactive and iterative process of mapping complex and fragile ecological developments. This article looks at computer-assisted cartography as part of environmental knowledge production. It uses InfoAmazonia, the data-journalism platform on Amazon rainforests, as an example of a geo-visualization within information mapping that enhances embodiment in the experience of the information. InfoAmazonia is defined as a digitally created map-space within which journalistic practice can be seen as dynamic, performative interactions between journalists, ecosystems, space, and species.

Cartography as Engagement

When addressing at the question: ‘What does Cartography mean to you?’ I reflected on my career in Cartography in order to properly provide an answer. At the very core of what it means to me is drawing the map and the very poetics of what we do to make maps ‘work’. However, it is more than the design and drawing (in its widest sense) of the map. It is the engagement in thinking about, developing and considering various design iterations and finally drawing the map. These process of problemsolving means that we need to think about the logics ‘behind’ the cartographic process, as well be attuned to what is actually feasible/possible for replicating and communicating the completed drawing, software, computer package or integrated media suite. My time in cartography has taken me from the era of pen and ink, to photo-mechanical production, to the early days of computer-assisted cartography, to digital cartography to the application of DeskTop Publishing to map production, to multimedia, the Web, to mobile mapping and, now, to the era of ubiquitous map provision and collaboration in cartography. When I started my career in cartography it was in the era of pen and ink. I worked for Shell Exploration as a cartographer. Here, the engagement with cartography was the design of a geologic or geophysical map, compiling information from (paper) resources, preparing the draughting film, constructing the grid, plotting the information from geologists fieldnotes (in pencil – probably a 5H, sharpened within an inch of its life with sandpaper), drawing lines with Rotring pens and adding lettering with Wrico lettering guides. Those hand-drawn lines and letters on plastic draughting film, once reproduced on a diazo printing machine, were used as tools to assist in making decisions about whether to embark on a costly geological exploration and drilling project. The engagement here was both a mental process (of map design – considering how all of the elements ‘fitted’ and accorded to geological mapping standards – and a tactile experience – actually handling the tools and making contact with the plastic draughting film, film cleaning pads, metal weights, Rotring pens and Wrico lettering guides, metal straight edges, erasers and razor blades. This engagement was rewarded through pleasure of completing a design, and drawing it by hand. The tactual experience of handling materials and manipulating tools resulted in a technical document that conveyed information from the geologist’s field book to decisionmakers. Unfortunately, my experience with scribing did not quite cut it – in terms of engagement. I really couldn’t become as engaged with the process of removing an emulsion from the top of stable plastics using a sapphire scribing tip. Yes, the process was accurate, produced standardized media and was quick, but the engagement was not the same as the tactual experience of actually drawing. The associated photomechanical processes were a bit different, especially when completing non-standard jobs. Manipulating images during the developing process was an art as well as a science, and techniques like warming parts of the photographic emulsion in certain areas of the film by hand to change the development process in that area produced some satisfying work outputs. I guess that there was more engagement with the photo-mechanical process. This was not so for me with scribing, perhaps due to the fact that what one could do with a drawing was more controlled.

Code as Cartography

It is now common practice to distribute maps not as static images, but as source code that renders in a web browser (Figure 1). This trend reflects the expansion of computer-assisted cartography ov...

Automated Dot Mapping: How to Dot the Dot Map

Dot mapping is a cartographic representation method to visualize quantitative absolute values, e.g. population figures, and spatial distribution patterns. In the course of the development of computer-assisted cartography many cartographic methods have already been implemented in computer algorithms, but for dot mapping only a few solutions with some considerable constraints have been found until now. The most important constraint is the lack of repeatable results because these solutions work with random dot placement. This may result in different maps, where the only real difference is the date of production, not the data that is mapped. Another constraint is the overlap of dots which may interfere with the user's intention to count the dots. Although, this last constraint may not be considered important by all, the first constraint is clearly problematic for the cartographer. This paper deals with the automated production of dot distribution maps which will not suffer from the above named constraints. The paper focuses on the placement of dots. It presents a method of placing dots in a centred manner as dot clusters grouping around one central point, e.g. the centroid of an enumeration area. The geometric basis is a spiral whirl. Besides the regular basis, the dot clusters should not be perceived as strict geometric figures and a pseudo-random element is therefore introduced to blur the symmetry of the dot clusters. Although, this blurring is apparently random, it is repeatable. The new approach is a first step to produce dot maps automatically by providing a mathematical structure to connect the area needed for placing the dots with the number and size of the dots. The method is meant to support cartographic laypersons as well as professional cartographers in the process of map design.

Localization of local soil classes in an arid region of Mexico, using satellite imagery

A map of local soil classes (LSCs) was used to make digital maps of soil classes using computer-assisted cartography. The objectives were to establish classes of the local soils of an arid locality; to determine their physical and chemical characteristics; to relate the content of clay (Cl), organic matter (OM) and electrical conductivity (EC) to the levels of reflectance from the classes of soil; and to obtain a digital map of classes of local soils using a supervised classification of the image and verify its precision. The map of LSCs was used as basis for generating information about the physical and chemical characteristics of soils. The information was related to digital levels of a Landsat 7 Enhanced Thematic Mapper Plus (ETM+) image, and a supervised classification was performed. The precision of the digital maps was verified. The results show that a map of LSCs can be used as basis for generating digital maps.

Computer-assisted cartography using topographic properties: precision and accuracy of local soil maps in central Mexico

Map units directly related to properties of soil-landscape are generated by local soil classes. Therefore to take into consideration the knowledge of farmers is essential to automate the procedure. The aim of this study was to map local soil classes by computer-assisted cartography (CAC), using several combinations of topographic properties produced by GIS (digital elevation model, aspect, slope, and profile curvature). A decision tree was used to find the number of topographic properties required for digital cartography of the local soil classes. The maps produced were evaluated based on the attributes of map quality defined as precision and accuracy of the CAC-based maps. The evaluation was carried out in Central Mexico using three maps of local soil classes with contrasting landscape and climatic conditions (desert, temperate, and tropical). In the three areas the precision (56 %) of the CAC maps based on elevation as topographical feature was higher than when based on slope, aspect and profile curvature. The accuracy of the maps (boundary locations) was however low (33 %), in other words, further research is required to improve this indicator.

Truth and Accountability in Geographic and Historical Visualizations

The research project Paper and Virtual Cities, financed by the Netherlands Organization for Scientific Research (NWO) and carried out by the Universities of Maastricht and Groningen, is developing new methodologies for the use of historical geographic sources in computer-assisted cartography. Manuscript and printed maps, atlases and other related texts are some of the sources we consider. One concept that is of particular interest at the onset of this project is that of the representation of 'truth' in geographic and historical visualizations.

Computer-assisted Cartography at the National Geographic Society

Computer-assisted Cartography at the National Geographic Society

Reorientation of Historical Maps of Old Fort Niagara Using Computer-Assisted Cartography

Since 1979 researchers at Old Fort Niagara (established 1726) in Youngstown, New York, have attempted to rescale and interpret historical maps and compile a composite showing where structures have been built within the parade area over the three centuries of the fort's history. This mapping work relates to an archaeological and historical research project focused on studying local and regional history, experimenting with nondestructive means of gaining information, and comparing field data with documented sources. While a vast corpus of contemporary maps was retrieved from French, British, Canadian, and American archives, these documents, drawn at various scales and for various purposes, exhibited such differences and planimetric skewing that they proved difficult to compare. Although initial studies of the available maps led to a general understanding of the fort's development, only with data from excavations and infrared studies and the application of computer-assisted cartography could the researchers determine actual building locations relative to the modern parade. The computer-assisted process also allowed depiction of remodeling phases of individual structures and enabled topological changes to be plotted. The decipherment of maps might be considered the initial step in an archaeological study of a historic site. Such cartographic studies were, however, more effective at Old Fort Niagara when excavation results and related infrared studies were used as supporting data for rescaling and realigning antique maps for comparative purposes.

Reorientation of Historical Maps of Old Fort Niagara Using Computer-Assisted Cartography

Reorientation of Historical Maps of Old Fort Niagara Using Computer-Assisted Cartography

AutoCAD as a cartographic training tool: a case study

A description is given of the use of AutoCAD as a tool for teaching students about computer-assisted cartography. The reasons for its selection are also discussed as are its limitations. Some examples demonstrating its capabilities are provided.

Technology And Education In A Developing Country/An Experience Involving Computer-Assisted Cartography And Indonesia

In 1983 the Midwest Universities Consortium for International Affairs (MUCIA) entered into an agreement with the Ministry of Education of the Government of Indonesia to implement World Bank Education Project IX. A major activity of the project was to bring consultants to three Indonesian universities in fields identified by the universities. One of these fields was computer-assisted cartography by the Facultas Geografi of Universitas Gadjah Mada (UGM). The position at Universitas Gadjah Mada was filled in sequence by two consultants including the author who spent from January to August 1987 in Jogyakarta. This paper discusses some of the problems and successes with acquiring, developing, converting and implementing software and a system for teaching.

Spatial distribution patterns of metals in the surface sediments of Lake Orta (Italy)

Lake Orta (North Italy) is one of the series of north-south oriented lakes on the southern slopes of the Alps. Pollution of this lake began in the late 1920s with massive discharges of ammonium sulphate and copper from a rayon factory; phytoplankton, zooplankton and fish eventually disappeared. In the following decades, a low-pH regime was established due to the in-lake oxidation of ammonium to nitrate, the geological setting (granite, gneisses, and micaschists) favouring this development by not offering sufficient buffer capacity to the lake. Additional human activities in the catchment area, since the mid-seventies, have added further metals such as chromium, nickel, zinc and lead. The concentrations of C, P, N, S, Si, Ca, Mg, K, Al, Fe, Mn, Cd, Cr, Cu, Ni, Pb, Zn, Hg and Ti were estimated on the basis of 57 grab samples, evenly taken over the whole lake. The samples were analyzed by non-destructive X-ray fluorescence spectrometry, differential pulse anodic stripping voltammetry and electrothermal atomic absorption spectrometry. Distribution maps have been drawn (by means of computer-assisted cartography) for each individual metal to assist in the assessment of the dispersion and accumulation effects. It is very likely that the metal enrichment observed in the sediments in the northeast section of Lake Orta has been caused by focusing phenomena. The mapping, together with statistical treatment of the results and comparison with previous data, has allowed hypotheses to be advanced about the origin and fate of the various pollutants, and suggestions to be made for the recovery of the lake.

The current state and the main trends in the development of geographical information systems in the U.S.S.R.

Abstract The paper falls into two parts. The approach to geographical information systems (GIS) in the U.S.S.R. and differences in terminology are first discussed. The main part of the paper comprises case studies on the design, construction and use of GIS and of computer-assisted cartography in the U.S.S.R. to illustrate the transition to the introduction of automated technologies to processing of geographical data for science, practice and education, the diversity of contexts, the problems tackled and their departmental attribution, and the territorial span, functional capabilities and technological equipment. The following trends of these developments are identified: the design of integrated GIS, an increase in their capabilities for modelling, the introduction of elements of expert systems, an orientation towards microcomputer technology, an awareness of the need to use standardized hardware and software (including linguistic terms) and a greater interest in the commercial and legal problems of GIS, international collaboration and education.

Historical evolution of disease mapping in general and specifically of cancer mapping.

The presentation of areal data in epidemiology is illustrated by such mapping techniques as dots (spots), shading (choropleth, thematic) and isolines (isopleths). Examples are also given of computer-assisted cartography (computer graphics) which employs hardware and software components of digital computers, together with the use of geographical and demographic base maps.

Computer-assisted Cartography

The paper gives an outline of computer-assisted cartography for geographers: a) main principles and devices, b) examples of map compilation with the help of the Scitex system, c) list of applications.

Personality as a Factor in the Development of a Discipline: The Example of Computer-Assisted Cartography

This paper is based upon the contention that human individuals can have a dramatic effect upon the development of a new discipline and, specifically, that this was indeed of major significance in the development of computer-assisted cartography. The development of the field in the UK up to 1973 is described from the viewpoint of a participant-observer and the significance of inter-personal relationships and 'turf battles' is outlined. It is concluded that one particular individual had a seminal effect upon developments in the UK and throughout the world.

Reviews: Central Place Theory, Gravity and Spatial Interaction Models, Industrial Location, Scientific Geography Series, Computer-Assisted Cartography: Principles and Prospects

Reviews: Central Place Theory, Gravity and Spatial Interaction Models, Industrial Location, Scientific Geography Series, Computer-Assisted Cartography: Principles and Prospects