KN - Journal of Cartography and Geographic Information最新文献

In late 2020, as soon as the approval of the first vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became foreseeable in line with the normative political goal of providing comparable living conditions to all residents of Germany irrespective of where they live, the German national government's national vaccination strategy called for the widespread establishment of COVID-19 vaccination centers. As the vaccination program has been rolled out, difficulties in accessing vaccination centers have been reported. Against this background, the paper considers the questions whether, where and for whom spatial inequalities in COVID-19 vaccination center accessibility in Germany might exist. Such an understanding might help to prepare for future situations when adequate disaster response requires, similar to the COVID-19 pandemic, the government to quickly reach great parts of the population in an efficient manner. To approach this question, we examine the accessibility by the means of transport foot, bicycle, car and public transport at small scale based on an accessibility model from the point of view of the "households". We found that in contrast to the common belief COVID-19 vaccination center accessibility or inaccessibility in Germany does not seem to be a spatial phenomenon cheating non-rural regions and discriminating rural regions as anticipated, it is instead strongly dependent on people's individual mobility capabilities in both rural and urban areas.

The proliferation of social media has resulted in its extensive use as a valuable source of information for researchers. This paper aims to use Twitter data to analyze and visualize tweets about the migration crisis in the European Union from 2016 to 2021. The paper uses a methodology to structure data for better understanding of complex social media data. The methods and metrics include the facet model of location based social media, the HyperLogLog data structure and novel uses of the metric typicality. The authors have also developed a web based interactive application closely following the methodology used to organize the dataset. Additionally the work also includes maps using spatial typicality which could be utilized for studying spatial phenomenon. The case study selected also provides unique insights and sets a template for working with multi-lingual geo-social media data. The authors believe that these methods and metrics could be reproduced for other case studies and aid in understanding and communication geo-social media data.

Supplementary information: The online version contains supplementary material available at 10.1007/s42489-022-00114-6.

Volunteered geographic information is often generated as voluminous point data, leading to geometric and thematic clutter when presented on maps. To solve these clutter problems, cartography provides various point generalization operations such as aggregation, simplification or selection. While these operations reduce the total number of points and therefore improve the readability, information preservation could be harmed when specific spatial patterns disappear through the generalization process, possibly leading to false interpretations. However, sets of map generalization constraints that maintain spatial pattern characteristics of point data are still missing. To define constraints that support synoptic interpretation tasks, user behaviour while solving these tasks has to be analysed first. We conduct a study where participants have to perform such interpretation tasks, using a new method that combines think-aloud interviews and techniques from visual analytics. We reveal that the point density of a dataset has the biggest impact on the user behaviour and the respective task-solving strategy, independently from the actual task type executed. Furthermore, our results show that the graphical map complexity only has a minor impact on the user behaviour, and there is no evidence that point data cardinality influences task execution and the solution-finding strategies.