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Relative accessibility is a widely studied approach that recognizes access to major locations as subjective and shaped by individual circumstances (e.g., individual preferences, habits, and cultural norms). One missing element in the knowledge base is how relative accessibility can be effectively mapped for decision-making. To fill the research gap, this paper evaluates whether cartograms are an appropriate tool for mapping relative accessibility, taking the city of Zaragoza, Spain as a case study. The research design included three phases: (i) elaboration of grid-based maps on relative non-motorized accessibility; (ii) elaboration of cartograms on relative non-motorized accessibility; (iii) an end-user evaluation with 30 local practitioners to analyze the effectiveness of cartograms to map relative accessibility compared to grid-based maps. Participants signaled that diffusion-based cartograms could be complementary to grid-based maps, providing better visualization of spatial dissimilarity patterns of accessibility between population groups. However, participants noted greater difficulty in identifying Dorling cartograms as an effective technique for mapping relative accessibility. The paper closes with a review of the strengths and weaknesses of the potential application of these visualization techniques in the field of accessibility planning.

Coronavirus disease 2019 (COVID-19) has emerged as a growing focus of global attention and a critical factor in public-health decision making. Towards fighting the COVID-19 outbreak, countries worldwide and international organisations have taken various actions, including promoting the transparency of and public access to disease data. In such public communications, maps have played an important role in that a map is worth a thousand words. Most of these have taken the form of a choropleth map. Here, we propose employing cartograms to visualise both the expansion and spread of COVID-19. We designed a combination of six circular cartograms containing the data of confirmed cases every 48 hours from 24 January to 3 February 2020. Such a design conveys both spatial and temporal information more intuitively and efficiently, so it can be expected to facilitate better public participation in the fight against COVID-19.

It is noteworthy that volumes of e-commerce usage are spread over the population of the world, and the amount of transactions is quite high. In this sense, Turkey's situation is different from other countries. Although the volume of internet usage is similar to that of the world, the volume of e-commerce transactions is quite low. However, there is a stable increase in the e-commerce usage in Turkey. Between 2016 and 2020, the average annual growth rate of e-commerce usage has grown by 31% across the country. Considering the great increase in the e-commerce usage in Turkey, this study aims to visualize spatial distribution of the share of e-commerce usage over the provinces of Turkey. Findings of the research point out that the e-commerce usage shows a heterogeneous spatial distribution across Turkey. Due to the low population, in particular provinces (such as Kayseri and Karabük in Central Anatolia, Aydın in Aegean Region, and Van in East Anatolia), there is an expanding distortion around these cities regarding the ratio of e-commerce usage.

The highway network is considered to be an effective solution for reducing regional differences and promoting high-quality economic development. This study mapped Sichuan’s highway network on an equal per capita GDP cartogram and on an equal highway freight volumes cartogram, which can provide a unique perspective to recognize the rationality of highway layouts and its coordination relationship with the population and economic development. The research result indicates that highway layouts are seriously affected by the topographical and geologic conditions, and the population and level of economic development are key influencing factors. It also shows that the density of the highway network is still seriously inadequate in the vast mountain and plateau area.

As the world’s largest carbon emitter, China is under great pressure to cut down carbon emissions. Understanding the evolution of carbon emissions across Chinese cities is important for policymakers when allocating carbon emission quota among these cities. This paper draws upon the Open-source Data Inventory for Anthropogenic CO2 to calculate city-level per capita carbon emissions in China from 2001 to 2016. Overall, we find that per capita carbon emissions of Chinese cities have been generally on the rise during the 2001–2016 period. However, there has been on average a modest decline in per capita carbon emissions of cities in China’s Yangtze River Delta region and Pearl River Delta region from 2011 to 2016, after a remarkable increase during the 2001–2011 period. Besides, the average north-south gap has been enlarged, with northern cities having a relatively higher level of per capita carbon emissions.

The visualisation of spatial information is a powerful tool for researchers in urban analytics seeking to convey their findings to the wider research community and the public in an accessible way. Yet, even the most well-intentioned cartographer may introduce misrepresentation by mapping irregularly shaped and sized areas. This paper explores the extent to which different methods of visualising area-based data can remedy (or exacerbate) this misrepresentation by presenting results from a crowdsourced survey. Data from the 2016 European Union referendum at Local Authority level in England are visualised using four alternative methods (balanced cartogram, hexogram, hexagonal grid, square grid) and compared to a traditional choropleth map, in terms of people’s understanding of the authors’ intended message, through a crowdsourced survey questionnaire. Results indicate that mapping out original boundaries can introduce misrepresentation, which can be mitigated by using balanced cartograms and hexograms to improve the accuracy of visualisations.

Half the population of Europe’s largest economy by population and economic output lives in 30 main urban agglomerations. This paper presents a series of cartogram visualisations of population chang...

Opening to the world is considered to be an important reason for China's rapid rise in recent decades. Due to China's unique geographical pattern, the eastern coastal areas have always been the window of China's interaction with the world. Although China's east-west openness gap has been widely recognized, mapping the huge gap is valuable in terms of recognizing mainland China. Foreign direct investment (FDI) reflects the long-term cooperative relationship between China and overseas, and FDI is deemed to show a high level of openness to the outside world. Based on the actual utilized amount of FDI capital of the prefecture-level cities in mainland China in 2016, this study developed an equal FDI capital map. The Yangtze River Delta (YRD) and the Pearl River Delta (PRD) are transformed into two much larger deltas, while non-delta-shaped regional units, including Beijing–Tianjin–Hebei (BTH), Fujian, Shandong, and Liaoning are also transformed into deltas of different scales. In addition, the distribution of FDI growth rates indicates that delta-shaped openness is being further strengthened in mainland China.

Ambient particulate matter air pollution (PM2.5) has been reported as a major pollutant that threatens human health, decreases visibility, and affects the regional and global climate. China, which is among world's most polluted countries of PM2.5, is faced with a severe challenge for PM2.5 mitigation. However, a lack of long-term PM2.5 concentration data on a large spatial scale has hindered comprehensive understanding of spatial and temporal variations of PM2.5 concentrations. Based on the satellite-derived PM2.5 concentration data, we generated maps of PM2.5 concentrations at county level in China. The cartogram and spatial analyst tool in ArcGIS 10.2 are used to visualize the changing temporal and spatial patterns of PM2.5 concentrations.

The rapid spread of information and communications technologies is accelerating the development of our economy and society. While information and communications technologies have become an important development tool that reshapes many aspects of the world’s activities, digital inequality emerges on a worldwide scale due to difference in access to and use of information and communications technologies. Digital inequality, which is a new phenomenon in the current information era, will widen the gap between developed and developing countries/regions. China has witnessed rapid informationization along with its booming economic growth over the past decade. However, digital inequality, as an important aspect of social inequalities in China, has received only scant attention currently. Based on the technique of cartogram, Figures display provincial information and communications technologies development index (IDI) values in 2010 and 2015 in China, exhibiting high inequality. Regions of the highest information and communications technologies levels are distributed along China's eastern coast. On the contrary, the provinces in the west present very low information and communications technologies levels. The coefficient of variation of IDI values dropped from 0.30 to 0.18, indicating declining digital inequality in China. A causal bidirectional relation probably exists between the economic development and information and communications technologies levels.

Science is happening in more countries, although the spread is geographically uneven. The geography of global science is evolving from a bipolar world to a tripolar pattern, and there are shifts in...

China, the world’s top CO2 emitter, is faced with pressure of energy-saving emission reduction. In the 2015 Paris Climate Conference (COP21), China announced its plan, aiming to cut down CO2 emissions by 60%–65% per unit of GDP in comparison to 2005’s level by 2030. To achieve this ambitious goal, reliable national, provincial, and city-level statistics are fundamental for multi-scale mitigation policy-makings as well as for the allocation of responsibilities among different administrative units. However, China implemented a top-down energy statistical system. The National Bureau of Statistics only publishes annually both national and provincial energy statistics. Only part of cities released their statistics, which results in missing data in city-level energy statistics. This also affects data transparency and accuracy of energy and CO2 emission statistics, and as a result, increases difficulty in allocation of CO2 emission reduction responsibilities. In order to fill this lacuna, we employed a standardized remote sensing inversion approach for estimating China’s city-level CO2 emissions from energy consumptions by integrating DMSP/OLS ‘city lights’ satellite data and statistical data. The end product is a map of city-level CO2 emissions in China. The most topping CO2 emitters are located in the major urban agglomerations along the more economically developed eastern coast (e.g. Yangtze River Delta, Beijing–Tianjin–Hebei, Shandong Peninsula, and Pearl River Delta). Other regions with high CO2 emissions are Shanxi and Henan in Central China, as well as the Chengdu–Chongqing and Shaanxi in West China. Regions with low CO2 emissions are western China, and most of Central China and South China.

In China, railways play a major role in inter-city travel. his study uses an equal population cartogram to plot the intercity railway network in Mainland China

England has some of the largest spatial inequalities in health in Europe – greater, for example, than those that currently exist between the former East and West of Germany (Bambra et al., 2014). People in the North of England are consistently found to be less healthy than those in the South – across all social classes and amongst both men and women (Dorling, 2010). The reasons for this are both compositional and contextual (Macintyre et al., 2002), reflecting uneven economic and social geographies (Dorling, 2010). It is also a long-standing health gap dating back to at least the 19th century (Bambra et al., 2014). It is popular to map these health inequalities using thematic choropleth, cartogram, or topological techniques. Our graphics expand on the latter by visualising the health divide between the North and South of England using some familiar national train journeys. It uses average life expectancy at birth for both women (Figure 1) and men (Figure 2) (data from Public Health England, 2015; reproduced under the Open Government Licence) along the West Coast Mainline (WCM, 300 miles, London Euston to Carlisle), the East Coast Mainline (ECM, 335 miles, London Kings Cross to Berwick), and the Great Western Mainline (GWM, 300 miles, London Paddington to Penzance). The data are georeferenced to each of the main stations along the routes using the relevant Local Authority (e.g. the data for Newark is for Nottinghamshire). Differently sized and coloured circles represent values above (large, green), around (medium, amber), or below (small, red) the English average of 79.4 years for men and 83.1 years for women. The visualisations show very clearly the health divides within a comparatively small country, particularly between the North East and South East regions which have the lowest and highest life expectancies respectively for both men and women. There are gaps of four years for men and five years for women between the best Southern and worst Northern areas. They also demonstrate a socio-spatial gradient with average life expectancy

Visualization of geographic variables as spatial objects of size proportional to variable strength is possible via generating cartograms. We developed a methodology based on mathematical morphology to generate contiguous cartograms. This methodology relies on weighted skeletonization by zone of influence. This weighted skeletonization by zone of influence determines the points of contact of multiple frontlines propagating from centroids of various planar sets (states) at the traveling rates depending upon the variable’s strength. The contiguous cartogram generated via this morphology-based algorithm preserves the global shape and local shapes and yields minimal area errors. We generated a cartogram for a population variable to demonstrate the proposed approach. Furthermore, the population cartograms for the United States generated via four other approaches are compared with the morphology-based cartogram in terms of errors with respect to area, local shape, and global shape. This approach for generating cartograms preserves the global shape at the expense of compromising with area errors. It is inferred from the comparative error analysis that the proposed morphology-based approach could be further extended by exploring the applicability of additional characteristics of B, which controls the dilation propagation speed and direction of dilation while performing weighted skeletonization by zone of influence, to minimize the local shape errors and area errors.

Marketing planners often use geographical information systems (GISs) to help identify suitable retail locations, regionally distribute advertising campaigns, and target direct marketing activities. Geographical information systems thematic maps facilitate the visual assessment of map regions. A broad set of alternative symbolizations, such as circles, bars, or shading, can be used to visually represent quantitative geospatial data on such maps. However, there is little knowledge on which kind of symbolization is the most adequate in which problem situation. In a large-scale experimental study, the authors show that the type of symbolization strongly influences decision performance. The findings indicate that graduated circles are appropriate symbolizations for geographical information systems thematic maps, and their successful utilization seems to be virtually independent of personal characteristics, such as spatial ability and map experience. This makes circle symbolizations particularly suitable for effective decision making and cross-functional communication.

Cartograms are a well-known technique for showing geography-related statistical information, such as population demographics and epidemiological data. The basic idea is to distort a map by resizing its regions according to a statistical parameter, but in a way that keeps the map recognizable. In this paper, we deal with the problem of making continuous cartograms that strictly retain the topology of the input mesh. We compare two algorithms that solve the continuous cartogram problem. The first one uses an iterative relocation of vertices based on scanlines. This algorithm explicitly accounts for induced shape error. The second one is based on the Gridfit technique, which uses pixel-based distortion based on a quadtree-like data structure. The basic idea is to insert pixels, the number of which corresponds to a statistical parameter, into the data structure and distort the pixels such that every pixel obtains a unique, nonoverlapping position. Relocation of vertices of the map are positioned using the same distortion. We discuss the results obtained from both methods, compare their shape and area trade-offs as well as their efficiency, and show results from different applications.

The author argues for the increased use of population cartograms to visualize changing geographies and uses British localities as an example. Population cartograms are increasingly being recognized by researchers as a major solution to many spatial visualization problems. The gross misrepresentation of many groups of people on conventional topographic maps has long been seen as a major problem of thematic cartography, highlighting difficulties such as the modifiable areal unit problem in preventing the development of visual palliatives. Population cartograms made up of many thousands of areal units are simple to construct with an appro pilate algorithm. The author has designed a particular solution for use in the visualization of high-resolution spatial social structure. The problem now is not of writing more computer programs, but of convincing other researchers of the necessity of using cartograms in place of conventional choropleth maps for showing many population-related distributions. The author shows how our pictures of space can be changed and argues why they should be.