Sextante: A geographic information system for Extremadura (Sextante)

Published on: 06/02/2009
SEXTANTE is a geographical information system (GIS) developed under the auspices of the government of the Spanish autonomous region of Extremadura. The GIS is freely available under GPL license, and incorporates a lot of feedback of the Open Source community. Built to fit the needs of the region's forestry department, the software is fast becoming an important tool for the management of Extremadura's diverse landscape. Its numerous analysis functions set SEXTANTE apart from other geographical information software.

Description of target users and groups

The project is mainly addressed to the needs of the foresters of the local government of Extremadura. Their requirements are thus top priority. However, as the project is freely available, the target group also expands, and the developers have enough leeway to take this into consideration as well.

Description of the way to implement the initiative

The University of Placencia, which offers the framework for Sextante, has close contacts with the local government. This made it very easy to convince the foresters department of the benefits of an improved and dedicated GIS. Only few bureaucratic steps were necessary for the implementation and to receive funding.

Technology solution

Large parts of SEXTANTE's initial architecture come from SAGA, which is a GIS developed at the University of Göttingen in Germany that has a strong focus on geo-analysis. Initially an additional 70 analysis modules on the basis of SAGA were developed, which already comprised around 120. At some point it became clear that the capabilities of the SAGA system would no longer meet the needs of the SEXTANTE project, as it was foreseeable that the analytical capabilities of SAGA would not satisfy the specific needs of the regional foresters at some point. The options were to either continue modifying SAGA, or to take SAGA's analytical algorithms and put implement them on top of a different base. The decision was made to move all the algorithms to gvSIG, which is a GIS developed by the region of Valencia, and which offers more functionality. Technology choice: Open source software

Main results, benefits and impacts

Before SEXTANTE was introduced to the forestry department, there was little use of computer programs to make the agency's work more efficient. Though a software application aiming to facilitate the work of the foresters was already deployed, hardly anyone was actually using it, or knew how to use it. The aim of SEXTANTE was to make more efficient the daily work of the foresters, who were still relying to a large extent on their practical knowledge of nature. Although some training of the foresters is still necessary and ongoing, the software finds use in the daily work of the department. This in turn facilitates the work largely. Besides the use of Sextante at the forestry department, an increasing number of users from all over the world make use of the software for their purposes. This offers a good source of feedback to the developers of Sextante.

Return on investment

Return on investment: Not applicable / Not available

Track record of sharing

As the software is freely available as an Open Source application, working together with the Open Source community is essential for the success of Sextante. The feedback coming from users all over the world enables the developers to react to specific needs and requests, as well as bugs very quickly. The OSOR.EU platform, amongst others, is an important meeting point for all kinds of users and people interested in Sextante. As their is already a lively GIS community at OSOR.EU, exchange of ideas and opinions between users and other developers is greatly facilitated. By constantly updating the code and as well as giving direct information about new developments, the community can participate and react directly to any developments of the software.

Lessons learnt

It was and still is important for the success of the project to be able to grow at a natural pace and to adapt to new possibilities and requirements step by step. In this respect the initial starting point of SEXTANTE on the SAGA platform can be considered vitally important, as it laid the foundation for SEXTANTE's success on a larger scale. The move to gvSIG was equally important, since more and more users found their way to SEXTANTE, and furthermore it improved the ability to develop the software according the needs or the regional foresters. Having a guaranteed funding gives the developers a substantial degree of freedom as to what they want to develop beyond the requirements of the foresters. Looking in the future it is however necessary to find more funding partners, as the financial dependence also bears the risk of having to shut down the project at some point. Scope: Local (city or municipality)