Augmenting thematic maps with interactive data-driven graphis by integrating open web APIs and mapping platforms

Abstract

Web is data rich and consuming available data sources from the web and visualizing them on a common web application platform can improve geographic information ecosystem and benefit GIS community in many aspects. Purpose of this master thesis was to improve thematic maps of an open source service integration platform by integrating open web API and providing interactive visualizations.

Theory part of the thesis begins with the evolution of the web to describe important concepts in web development such as web services, web APIs, web 2.0, mashups, REST and AJAX. It continues with the concept of spatial data infrastructure, INSPIRE and Open Geospatial Web Services. Later, open source technologies that are used in development part of the case study, are introduced. Lastly, it introduces information visualization, visualization seeking mantra, basic data visualization types and also gives basic design principles for the multiple view system.

Since Oskari is the main entry point for geographic data in Finland, Oskari is chosen as an open source service integration platform for the case study. It has been identified that the platform integrates only one API from Statistics of Finland for thematic maps functionality. This could be improved by integrating more statistical data sources and creating suitable charts. PX Web API includes statistical data sources around the world. As a data source, Helsinki PX Web API that exposes statistical data about the city of Helsinki, is chosen. The intention for choosing PX web API was that adopting one of them would lead to create a generic solution for all of them in the future. Previously, there have been several attempts to visualize PX web API sources on Oskari. These attempts failed due to complexity of Oskari and PX Web API. Case study showed that it is possible to visualize statistical data from PX Web APIs on Oskari and support thematic maps with more data sources and different visualizations. Case study also addresses that the service integration platform can serve as a statistical data exploration platform with multiple views by using available data sources from the web.