City Focus is a webbased

interactive 2D and 3D GIS application to find the best place in a city

to live as well as to pass shorter staying. The user can select among different criteria and decide

their importance by assigning weights to each of them. The application provides thematic maps

displaying insights on the places which better fit the user’s preferences. The resulting map is

computed through map algebra by means of Web Coverage Processing Service WCPS provided

by RASDAMAN Database Management System. Data visualization is mainly based on NASA

Web WorldWind opensource

virtual globe. The app exploits exclusively open data as well as

Free and Open Source Software (FOSS) for its implementation by enabling continuous

improvements while minimizing development costs

Arias Muñoz, Carolina

Corti, Simone

Molinari, Monia Elisa

Oxoli, Daniele

Prestifilippo, Gabriele

City Focus is a webbased
interactive 2D and 3D GIS application to find the best place in a city
to live as well as to pass shorter staying. The user can select among different criteria and decide
their importance by assigning weights to each of them. The application provides thematic maps
displaying insights on the places which better fit the user’s preferences. The resulting map is
computed through map algebra by means of Web Coverage Processing Service WCPS provided
by RASDAMAN Database Management System. Data visualization is mainly based on NASA
Web WorldWind opensource
virtual globe. The app exploits exclusively open data as well as
Free and Open Source Software (FOSS) for its implementation by enabling continuous
improvements while minimizing development costs

ARIAS MUNOZ, CAROLINA

MOLINARI, MONIA ELISA

OXOLI, DANIELE

PRESTIFILIPPO, GABRIELE

Archivio istituzionale della ricerca - Politecnico di Milano

City Focus: A web­based interactive 2D and 3D GIS application to find the best place in a city, using open data and open source software Carolina Arias Muñoz, Simone Corti, Monia Elisa Molinari, Daniele Oxoli, Gabriele Prestifilippo Department of Civil and Environmental Engineering, Politecnico di Milano Como Campus, Como, Lombardy, Italy  Corresponding Author:  Carolina Arias Muñoz Via Vallegio 11, Como, Lombardy, 22100, Italy Email address: carolina.arias@polimi.it  Session: CitySmart, Open Source Apps for Urban Management (chair: Hogan; Brovelli)  Abstract  City Focus is a web­based interactive 2D and 3D GIS application to find the best place in a city                                     to live as well as to pass shorter staying. The user can select among different criteria and decide                                   their importance by assigning weights to each of them. The application provides thematic maps                           displaying insights on the places which better fit the user’s preferences. The resulting map is                             computed through map algebra by means of Web Coverage Processing Service WCPS provided                         by RASDAMAN Database Management System. Data visualization is mainly based on NASA                       Web WorldWind open­source virtual globe. The app exploits exclusively open data as well as                           Free and Open Source Software (FOSS) for its implementation by enabling continuous                       improvements while minimizing development costs.   Keywords: Open data Free and Open Source Software NASA Web WorldWind RASDAMAN,                       MyGEOSS  1. Introduction  City Focus is a work­in­progress application, winner of the MYGEOSS third call for innovative                           Apps, launched by the European Commission           (​http://digitalearthlab.jrc.ec.europa.eu/mygeoss/results3.cfm​). The call focused on developing           applications of European relevance able to provide users with quantitative or qualitative                       information on the changing environment, taking into account broad environmental or social                        PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2232v2 | CC BY 4.0 Open Access | rec: 26 Sep 2016, publ: 26 Sep 2016themes across geographic scales, stressing the use of openly available or crowd­generated data in                           different domains addressing citizens’ needs (Raglia & Craglia, 2015). City Focus is a web­based interactive 2D and 3D GIS application to find the best place in a city                                     to live, or to pass shorter staying. The user can select among different criteria and decide their                                 importance by assigning weights to each of them. The application provides thematic maps                         displaying insights on the places which better fit the user’s preferences. The resulting map is                             computed through map algebra upon a cascade of pre­built raster maps. Users are guided in the                               requests through a predefined list of criteria including: air quality, precipitation, terrain                       morphology (e.g. slope, solar exposure, etc.), temperature, proximity to urban facilities (e.g.                       schools, transportations, sports fields, cultural attractions, healthcare centers, parking lots, shops,                     etc.), presence of public spaces, land use characteristics (e.g. commercial areas, residential areas,                         etc.), population density, traffic or internet connection.   2. City Focus application data  As required by the ​MyGEOSS call, we focus on fully open data available for the city of Milan,                                   which was selected as initial case study for the first app implementation. Suitable data sources                             were: Open Data Lombardia (​https://www.dati.lombardia.it​), Dati Comune Milano               (​http://dati.comune.milano.it​), OpenStreetMap (​https://www.openstreetmap.org​). These include         vector layers regarding urban facilities (e.g. public transports, public green areas, etc.), primary                         services (e.g. schools, hospitals, commercial centers, etc.) as well as recreational services.                       Environmental and meteorological data instead were retrieved from different sources. Examples                     are maps of temperatures from EuroLST dataset (​http://www.geodati.fmach.it/eurolst​) as well as                     DTM and land cover maps from SINAnet geoportal (​http://www.sinanet.isprambiente.it​).   Due to the different formats, spatial extension and resolution of the data, a preliminary                           processing was required to feed the application database with homogeneous information. ​The                       goal was to produce raster maps containing information about ​presence​, ​spatial concentration or                         proximity to any of the city features described by the data collected. ​Regarding point data (​e.g.                               primary services, urban facilities, etc.), data from different sources were merged in a single                           shapefile and all the possible duplicates were filtered out by means of buffers. Concentration                           maps were computed using v.kernel module of GRASS GIS (​https://grass.osgeo.org​). Polygonal                     features (e.g. parks, water bodies, etc.) were instead first rasterized and then, multiple­distance                         buffer maps were generated by means of r.buffer GRASS GIS module, to represent both                           presence and proximity to these features.  Raster maps obtained in the previous steps as well as those data originally sourced in raster                               format were re­sampled according to an equal grid in order to harmonized both layers extension                             1 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2232v2 | CC BY 4.0 Open Access | rec: 26 Sep 2016, publ: 26 Sep 2016and cell resolution. Cell values were then normalized to allow the computation aimed to the                             generation of the output map, performed by the server side as explained in the following                             paragraphs.   3. Application  architecture and processing:   The server side is based on the RASDAMAN Database Management System                     (​http://www.rasdaman.com​) for data storage and processing while the client exploits the NASA                       Web WorldWind open­source virtual globe (https://webworldwind.org) for geospatial data                 visualization.   Recently, RASDAMAN has arisen as a scalable and cost­effective database solution to store and                           retrieve multi­dimensional raster data (arrays). RASDAMAN conceptual model consists of                   multidimensional arrays with n­dimensions extend. Data storage relies on partitioning of the                       arrays into sub­arrays called tiles, which can be stored either in a relational database, in files in                                 the data systems or archives of files that can be accessed externally (Baumann et al., 1999). Data                                 processing within RASDAMAN is done through the Web Coverage Processing Service WCPS,                       which defines a protocol­independent language for the extraction, processing, and analysis of                       arrays (Open Geospatial Consortium, 2009), that can include complex operations such as slicing                         or trimming, induced operations (arithmetic, exponential, trigonometric among others),                 condensers (count, avg, some, all), metadata extraction or reprojection (Aiordăchioaie, A. &                       Baumann, P., 2010).  NASA Web WorldWind is an open­source virtual globe, which allows to display several kinds                           of geospatial data also in three­dimension. It runs on all the modern browsers thanks to WebGL,                               JavaScript, and HTML5. Web WorldWind comes along with a rich set of APIs (application                           programming interfaces) enhancing the possibility for developers of customization as well as                       implementation of new functionalities. It allows to display different kinds of data in a                           three­dimensional globe and it’s compliant with different OGC standards such as WMS and                         KML.  The application’s architecture is summarized in the following figure:  2 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2232v2 | CC BY 4.0 Open Access | rec: 26 Sep 2016, publ: 26 Sep 2016 Figure 1. City Focus architecture  On the server side, ​RASDAMAN provides many functionalities to process raster datasets. The                         calculations are performed using WCPS requests. Data are accessed over the web by the                           Petascope component of RASDAMAN, translating incoming WCPS requests into RASDAMAN                   rasql queries to efficiently process the different raster maps and generate the output map. The                             City Focus application relies on a standard installation of RASDAMAN server with a SQLite                           database backend.   For what it concerns the client side, different tools were considered to build up the interface for                                 maps visualization. These were mainly jQuery (​https://jquery.com​) a light JavaScript library to                       interact with the HTML page and NASA Web WorldWind for maps visualization, both in two                             and three dimensions considering the terrain elevation. Combining jQuery and Web                     WorldWind, it is possible to retrieve maps from RASDAMAN through the WPCS and show                           them to the end­user. On the graphical side, jQuery UI (​https://jqueryui.com​) and Bootstrap                         (​http://getbootstrap.com​) allowed creating dynamic components such as sliders, buttons, and                   3 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2232v2 | CC BY 4.0 Open Access | rec: 26 Sep 2016, publ: 26 Sep 2016forms. These libraries have been adopted to enable users’ selection of weights for the available                             criteria.   As shown in the application mockup included in figure 2, the users will be asked to assign a                                   proper weight to each criterion by simply moving these sliders from the app interface. Users’                             preferences will be automatically sent to the server employing a WPCS request. The output                           consists of a raster “score map” computed as a weighted average of the normalized raster maps                               representing the user’s selected criteria. The final map is then displayed with an intuitive color                             gradient, enabling the user to identify the best places within the city which better fits his/her                               preferences.  4 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2232v2 | CC BY 4.0 Open Access | rec: 26 Sep 2016, publ: 26 Sep 2016   Figure 2. City Focus architecture   4. Discussion and future developments  Most of the existing apps (see http://teleport.org, http://www.findyourspot.com,               http://where2roost.com) focus on finding a city to live and not on identifying a suitable place                             5 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2232v2 | CC BY 4.0 Open Access | rec: 26 Sep 2016, publ: 26 Sep 2016within a city, which implies a higher level of information accuracy and a deeper analysis scale.                               The existing apps also allow searching for places to live by specifying few parameters such as                               apartment or house prices. In this cases, once the user has chosen a location, it might need to                                   retrieve additional information about the place in order to make a decision. This application will                             help to perform this task in an automatic as well as user­friendly way avoiding long and                               hand­made search on the Web. City Focus takes into account environmental conditions such as                           air quality levels or microclimate conditions, that existing apps do not consider. The app                           exploits exclusively open data as well as Free and Open Source Software (FOSS) for its                             implementation by enabling continuous improvements while minimizing development costs.  Possible improvements regard the possibility for users to get a glimpse of the changing                           environment within a city through a trend maps or graphs for any specific criterion (e.g.                             temperature changes in the last five years, etc.) This can also be helpful while selecting weights                               for each of them. Moreover, name of best scored city blocks from the final map (i.e. the cells                                   with the highest scores) may be displayed too, associating to these cells to neighborhoods by                             means of geocoding.  As a first case study, we considered the city of Milan. In the future, other italian as well as                                     european cities are planned to be included.  Acknowledgements  The application is being developed within the MyGEOSS project, which has received funding                         from the European union's Horizon 2020 research and innovation programme.  5. References  Aiordăchioaie A., Baumann P. 2010. PetaScope: an open­source implementation of the OGC                       WCS geo service standards suite. In: Scientific and Statistical Database Management. Springer,                       160–168.  Baumann P., Dehmel A., Furtado P., Ritsch R., Widmann N. 1999. Spatio­temporal retrieval                         with RasDaMan. In: VLDB. 746–749.  Raglia E., Craglia M. 2015. MYGEOSS Project. GeoInformatics 18:38.  Open Geospatial Consortium. 2009. Web Coverage Processing Service (WCPS) Language                   Interface Standard. 6 PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.2232v2 | CC BY 4.0 Open Access | rec: 26 Sep 2016, publ: 26 Sep 2016

City Focus: A web-based interactive 2D and 3D GIS application to find the best place in a city, using open data and open source software

https://re.public.polimi.it/bitstream/11311/1010665/1/peerj-preprints-2232.pdf

City Focus: A web-based interactive 2D and 3D GIS application to find the best place in a city, using open data and open source software

Abstract

Similar works

Full text

Available Versions

Archivio istituzionale della ricerca - Politecnico di Milano