Introduction
The Alps are one of the largest continuous natural areas in Europe, with outstandingly unique and diverse landscapes, habitats, culture and history. The Alpine Convention entails the guiding principles towards a sustainable life in the Alps, now and in the future. Article 3 and 4 of the Alpine framework Convention invites the contracting parties to promote research, cooperation, monitoring activities and knowledge dissemination. Within this framework, the Alpine Convention Atlas is the operative tool of the System for the Observation and Information on the Alps (SOIA), providing seamless accessibility and usability of the AC datasets for several stakeholders. The AC Atlas is based on GeoNode Corti et al. (2019), an open-source web framework to deploy geospatial content management systems (GeoCMS) and spatial data infrastructure (SDI) (Kralidis (2007), Nebert (2004). GeoNode allows data providers and users to share geographical data and combine them in thematic maps allowing interoperability by adopting Open Geospatial Consortium (OGC) standards, such as Web Map Service (WMS), Web Feature Service (WFS), Web Coverage Service (WCS) and Catalog Service for the Web (CSW). GeoNode distinguishes different entities: documents, layers and thematic maps. Every single entity is linked with a comprehensive metadata description. Document definition is generic; in fact, several documents types are allowed: for example, “.doc, .pdf .jpeg, .ppt, .xls, .txt etc.”. A Layer is a spatial dataset, vector or raster type. Each layer can be associated with different styles (which describes the legend) and in the case of the vector layer with a data attribute table. A thematic map is a composition of different layers where each layer can be internal or from remote services using OGC standards. Additional tools to filter features, create graphs and to visualise time-series, are provided in the map interface. A comprehensive GeoNode description can be found in the GeoNode documentation and in Corti et al. (2019).
The Alpine Convention spatial data infrastructure
The Alpine Convention spatial data infrastructure (SDI) is based on GeoNode 3.0 installed in a dedicated Virtual Machine (VM) at the front end. It uses GeoServer 2.16.2 as its internal spatial data server. Data are stored in a spatial database, based on PostgreSQL 11. The GeoNode, the Database and the Geosever are installed on a distributed system and run on the private cloud platform of Eurac Research.
Usage
The Alpine Convention Atlas Fig. 1 distinguishes between two kind of users (Public and registered users). The public viewers (not authenticated user) can freely browse the AC Atlas to discover the dataset. The catalogues of documents, layers and maps allow searching the available data by simple text search or predefined filters, such as by keyword, data type (i.e. vector, raster, time-series), categories (i.e. agriculture, climate etc.), responsible, groups, groups categories, date, region and extent. In the layer preview pages, the user can view the layer and its summarised metadata. Finally, public users can view the full extent layer or map, changing opacity and add further layers from the catalogue. Registered users can fully exploit the GeoNode features of uploading and sharing datasets, editing styles and metadata, assigning several tags and properties, creating maps and setting specific permissions. The Atlas home page elements are Data, Maps, People, About, Registration and Sign-in sections. For simplicity, this paper briefly illustrates the page elements visible when a registered user is signed in. Under data, users can access the catalogue of the available Layers and Documents. It is, moreover, possible to Upload Layer or Upload Document. Finally, it is possible to add remote layers or view existing registered remote layers by clicking Remote services. Under Maps, the users can Explore Thematic Maps existing in the catalogue or Create Thematic Map. Under the People section, all the registered users are listed, as well as all the existing Groups and Group Categories, while the Invite users function allows inviting external people by sending an email. In the About section, users can find further Info, read the Terms of use and find Contacts details. Finally, in Get Started, users can find useful tips and tricks. Once the user Registers and Signs in, the username dropdown menu appears, through which the users can access and edit their Profile, check their Recent Activity and view their Favorites layers, maps and documents. In Inbox, the user finds all the messages sent and received within the AC Atlas user community.