WebGIS

Web GIS originates from a combination of web technology and Geographic Information Systems. Essentially it is a GIS system that uses web technologies to make data accessible to the public regardless of whethter or not they have a background and knowledge about GIS. Hence the main objective of webGIS is informing people through interactive maps. The user interface is very simple and allows a fairly straightforward navigation through the map. WebGIS projects can be built using basic functions, e.g. zoom in and out, or by area, search for place names, and switch on and off the layers. Alternatively, a webGIS can be a bit more complex and allow the users to access the attribute table of the layer by clicking on a feature on the map, editing layers, or filtering the data.

Considering the IT constraints, the internet limitations and the resources available (staff and money) that are shared by the UKOTs in the South Atlantic region, it was necessary to adopt a very simple approach for the development of webGIS services. The simplest architecture of a Web GIS requires one server, with a web application, and one client that is a desktop application or web browser application that allows the user to communicate with the server.

QGIS is the GIS tool used in the Falkland Islands, Ascension and Saint Helena and with the plugin Lizmap provides the simplest platform for creating webGIS services. The steps for publishing online are four:

  1. Set up the server with GIS, PostgreSQL and web application (Lizmap, Apache, php)
  2. Create the QGIS project based on data coming from a database (postgresql)
  3. Use the Lizmap plugin to publish the project online
  4. Transfer the project and the data via FTP from local to the server with the web applications

(Credit: http://www.3liz.com/lizmap.html)

Ascension, Saint Helena and the Falkland Islands share one cloud server which i property of NaturalGIS, a consultancy company run by Giovanni Manghi and Vania Neves. Giovanni is also one of the main contributors to the development of QGIS. Giovanni spent three weeks in the Falklands in January 2016 delivering a training course to the SAUKOTs data managers in PostgreSQL/PostGIS and Lizmap. From there onwards, he has helped enormously in providing technical support and advice on the management of the server (Ubuntu - Linux) and the spatial databases. The cloud server, which is remotely maintained by Giovanni, has been made accessible to the data manager in the Falkland Islands so that the QGIS projects, ready to become "webGIS projects", can be uploaded and published.

In order to publish a webGIS project from Ascension or Saint Helena, the local data managers need to send the QGIS projects and the backup of their database (data are all stored in PostgreSQL database except for the raster files which are sent individually) to the data manager in the Falkland Islands who is responsible for uploading them onto the cloud server. 

Recently, Sam Weber, who is now based at the University of Exeter (Falmouth campus), has been able to set up on the University server, a QGIS server and Lizmap. In this way he is able to publish webGIS projects for Ascension Island independently.

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