Enrichment of OpenStreetMap data completeness with sidewalk geometries using data mining techniques

Tailored routing and navigation services utilized by wheelchair users require certain information about sidewalk geometries and their attributes to execute efficiently. Except some minor regions/cities, such detailed information is not present in current versions of crowdsourced mapping databases including OpenStreetMap. CAP4Access European project aimed to use (and enrich) OpenStreetMap for making it fit to the purpose of wheelchair routing. In this respect, this study presents a modified methodology based on data mining techniques for constructing sidewalk geometries using multiple GPS traces collected by wheelchair users during an urban travel experiment. The derived sidewalk geometries can be used to enrich OpenStreetMap to support wheelchair routing. The proposed method was applied to a case study in Heidelberg, Germany. The constructed sidewalk geometries were compared to an official reference dataset ("ground truth dataset"). The case study shows that the constructed sidewalk network overlays with 96% of the official reference dataset. Furthermore, in terms of positional accuracy, a low Root Mean Square Error (RMSE) value (0.93 m) is achieved. The article presents our discussion on the results as well as the conclusion and future research directions

The use of Volunteered Geographic Information (VGI) and Crowdsourcing in Disaster Management: a Systematic Literature Review

The number of crisis events around the world has been increasing in the last years and suggests there is a real need to make communities more resilient to them. In addition to providing conventional authoritative data, ordinary citizens and residents in the affected areas are also voluntarily supplying information about the affected areas, in what has been called Crowdsourced or Volunteered Geographic Information (VGI). This paper conducts a Systemic Literature Review aimed at assessing the current state of research in the use of VGI as a source of information to aid the management of disasters. The results suggest there is an increasing body of knowledge of VGI and the way it can improve disaster management. It also reveals gaps in the use of VGI in the research areas of ‘preparedness’ and ‘recovery’, as well as the need for more robust case studies and experimental research to support this promising field

The sketch map tool facilitates the assessment of OpenStreetMap data for participatory mapping

A worldwide increase in the number of people and areas affected by disasters has led to more and more approaches that focus on the integration of local knowledge into disaster risk reduction processes. The research at hand shows a method for formalizing this local knowledge via sketch maps in the context of flooding. The Sketch Map Tool enables not only the visualization of this local knowledge and analyses of OpenStreetMap data quality but also the communication of the results of these analyses in an understandable way. Since the tool will be open-source and several analyses are made automatically, the tool also offers a method for local governments in areas where historic data or financial means for flood mitigation are limited. Example analyses for two cities in Brazil show the functionalities of the tool and allow the evaluation of its applicability. Results depict that the fitness-for-purpose analysis of the OpenStreetMap data reveals promising results to identify whether the sketch map approach can be used in a certain area or if citizens might have problems with marking their flood experiences. In this way, an intrinsic quality analysis is incorporated into a participatory mapping approach. Additionally, different paper formats offered for printing enable not only individual mapping but also group mapping. Future work will focus on advancing the automation of all steps of the tool to allow members of local governments without specific technical knowledge to apply the Sketch Map Tool for their own study areas

Enrichment of OpenStreetMap data completeness with sidewalk geometries using data mining techniques

Tailored routing and navigation services utilized by wheelchair users require certain information about sidewalk geometries and their attributes to execute efficiently. Except some minor regions/cities, such detailed information is not present in current versions of crowdsourced mapping databases including OpenStreetMap. CAP4Access European project aimed to use (and enrich) OpenStreetMap for making it fit to the purpose of wheelchair routing. In this respect, this study presents a modified methodology based on data mining techniques for constructing sidewalk geometries using multiple GPS traces collected by wheelchair users during an urban travel experiment. The derived sidewalk geometries can be used to enrich OpenStreetMap to support wheelchair routing. The proposed method was applied to a case study in Heidelberg, Germany. The constructed sidewalk geometries were compared to an official reference dataset (“ground truth dataset”). The case study shows that the constructed sidewalk network overlays with 96% of the official reference dataset. Furthermore, in terms of positional accuracy, a low Root Mean Square Error (RMSE) value (0.93 m) is achieved. The article presents our discussion on the results as well as the conclusion and future research directions

A Framework of Quality Assessment Methods for Crowdsourced Geographic Information: a Systematic Literature Review

Crowdsourced Geographic Information (CGI) has emerged as a potential source of geographic information in different application domains. Despite the advantages associated with it, this information lacks quality assurance, since it is provided by different people. Therefore, several authors have started investigating different methods to assess the quality of CGI. Some of the existing methods have been summarized in different classification scheme. However, there is not an overview of the methods employed to assess the quality of CGI in the absence of authoritative data. On the basis of a systematic literature review, we found 13 methods that can be employed to this end

Exploring the Geographical Context for Quality Assessment of VGI in Flood Management Domain

Volunteered Geographic Information (VGI) has been used to complement or substitute authoritative data in flood management domain. The main issue regarding the use of volunteered information is to estimate its quality, mainly because it may suffer from heterogeneous quality. Therefore, several methods have been developed in the past few years in order to assess VGI quality. However, existing works lack in assessing VGI quality for the purpose of flood management. To overcome this gap, we propose a method for assessing the quality of VGI for this purpose. This method uses a set of quality metrics that were developed for measuring VGI plausibility. A multiple linear regression was carried out in order to demonstrate the relationship between VGI plausibility and the quality metrics. The results showed that plausibility can be explained by 5 quality metrics. Thus, the proposed method is able to estimate the plausibility of VGI in flood management domain

Exploring the geographical context for quality assessment of VGI in flood management domain

Volunteered Geographic Information (VGI) has been used to complement or substitute authoritative data in flood management domain. The main issue regarding the use of volunteered information is to estimate its quality, mainly because it may suffer from heterogeneous quality. Therefore, several methods have been developed in the past few years in order to assess VGI quality. However, existing works lack in assessing VGI quality for the purpose of flood management. To overcome this gap, we propose a method for assessing the quality of VGI for this purpose. This method uses a set of quality metrics that were developed for measuring VGI plausibility. A multiple linear regression was carried out in order to demonstrate the relationship between VGI plausibility and the quality metrics. The results showed that plausibility can be explained by 5 quality metrics. Thus, the proposed method is able to estimate the plausibility of VGI in flood management domain

Enhancing Usability of a Citizen Observatory Based on User-Centered Design

Several crowdsourcing-based systems have been employed to gather information from individuals in natural disaster domain. They involve a wide diversity of users, which make their usability an important aspect. This article deals with the understanding of users' needs and design of a new interface for the Citizen Observatory of Floods. An User-centered Design (UCD) approach was employed and users were the main focus of the development process. The outcomes of a heuristic evaluation conducted revealed several problems of the prototype regarding usability aspects

Development of a spatial decision support system for flood risk management in Brazil that combines volunteered geographic information with wireless sensor networks

Effective flood risk management requires updated information to ensure that the correct decisions can be made. This can be provided by Wireless Sensor Networks (WSN) which are a low-cost means of collecting updated information about rivers. Another valuable resource is Volunteered Geographic Information (VGI) which is a comparatively new means of improving the coverage of monitored areas because it is able to supply supplementary information to the WSN and thus support decision-making in flood risk management. However, there still remains the problem of how to combine WSN data with VGI. In this paper, an attempt is made to investigate AGORA-DS, which is a Spatial Decision Support System (SDSS) that is able to make flood risk management more effective by combining these data sources, i.e. WSN with VGI. This approach is built over a conceptual model that complies with the interoperable standards laid down by the Open Geospatial Consortium (OGC) – e.g. Sensor Observation Service (SOS) and Web Feature Service (WFS) – and seeks to combine and present unified information in a web-based decision support tool. This work was deployed in a real scenario of flood risk management in the town of São Carlos in Brazil. The evidence obtained from this deployment confirmed that interoperable standards can support the integration of data from distinct data sources. In addition, they also show that VGI is able to provide information about areas of the river basin which lack data since there is no appropriate station in the area. Hence it provides a valuable support for the WSN data. It can thus be concluded that AGORA-DS is able to combine information provided by WSN and VGI, and provide useful information for supporting flood risk management

Enrichment of OpenStreetMap Data Completeness with Sidewalk Geometries Using Data Mining Techniques

Tailored routing and navigation services utilized by wheelchair users require certain information about sidewalk geometries and their attributes to execute efficiently. Except some minor regions/cities, such detailed information is not present in current versions of crowdsourced mapping databases including OpenStreetMap. CAP4Access European project aimed to use (and enrich) OpenStreetMap for making it fit to the purpose of wheelchair routing. In this respect, this study presents a modified methodology based on data mining techniques for constructing sidewalk geometries using multiple GPS traces collected by wheelchair users during an urban travel experiment. The derived sidewalk geometries can be used to enrich OpenStreetMap to support wheelchair routing. The proposed method was applied to a case study in Heidelberg, Germany. The constructed sidewalk geometries were compared to an official reference dataset (“ground truth dataset”). The case study shows that the constructed sidewalk network overlays with 96% of the official reference dataset. Furthermore, in terms of positional accuracy, a low Root Mean Square Error (RMSE) value (0.93 m) is achieved. The article presents our discussion on the results as well as the conclusion and future research directions