OSGeo Events, FOSS4G 2008

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Use of Open Sources GIS tools to build the RISKMED early warning system web portal for severe weather events

Gian Paolo Marra, Dario Conte, Mario Marcello Miglietta, Agata Moscatello

Last modified: 2008-11-07


The main objective of the RISKMED (INTERREG III B ARCHIMED area) project is to build an early warning system for severe weather events (e.g. heavy rain and snowfall, strong surface winds, high waves, extreme temperatures) occurring over the Central and Eastern Mediterranean. In the frame of the core activities, the partner CNR-ISAC, has developed a Data Gathering System (DGS) able to offer a versatile handling method to gather data coming from meteorological prognostic models in order to provide real-time risk assessment information over specific sub-areas of southern Italy. The entire system is based on GIS (Geographic Information Systems) approach and fully developed using Open Source components in order to display actual and forecast weather variables over the selected risk alert areas. The selected risk areas are stored into a geographic database in form of vectorial geographic boundaries for both land and sea surfaces. The DGS is available for public user from http://riskmed.le.isac.cnr.it. The system has been developed using Open Source software for both GIS components (geo-processing libraries, digital mapping tools, etc.) and database management system (RDBMS with GIS extensions). The utilization of a RDBMS systems that provides GIS functionalities improves the efficiency in such an operation because it gives a structured workspace for information storage and retrieval. Nowadays, several software solutions are available also within the GIS industry worldwide relatively to both commercial and open source products. In particular, the available open source GIS projects provide several powerful tools that answer the major requirements in both the scientific and the industrial applications. These open sources tools permit to embrace affordable low-cost software projects that can be utilized by the scientific community. Among the available Open Source projects, the components matching our needs have been selected. In particular, the following key tools have been used:
- PostgreSQL with PostGIS extensions with OGC specifications enabled are used as GIS enabled enterprise database;
- GDAL/OGR Geospatial Data Abstraction Library/Simple Features Library are adopted as data format/geographic reference and projection conversion utilities;
- PROJ.4 Cartographic Projections library are exploited as geo-processing libraries;
- UMN (University of Minnesota) MapServer are used as Web Mapping Tool;
- Ruby on Rails are used as web application framework.
The web application interface includes several functionalities which allow the users to visualize data alert forecast products through geographic map images and textual lists sorted by several criteria such as warning level, area, kind of surface (land or sea), etc. Map images show the alert affecting each area with different colours according to the predicted alert level.
From web portal, users can also download text files which contain alert information with format defined by the centralized RISKMED System. More in detail, the application was developed using Ruby scripting language (configured to work with MapScript module) and following a modular strategy and an object oriented pattern, in order to allow an easy extension of the prototype. In particular, Ruby Mapscript module is a Ruby dynamically loadable module that makes MapServer's MapScript functions and classes available in a Ruby environment. All front end scripts are developed using the Model-View-Controller design paradigm by mean of Ruby on Rails free web application framework. Rails aims to increase the speed and ease with which database-driven web sites can be created, and offers skeleton code frameworks from the outset.

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