Technological development and increasing awareness of geographical data and its use has triggered exponential growth in digital content. This has not, however, been accompanied by measures for dissemination and accessibility. Geographical data is typically clustered by application segments and reuse of data is often not foreseen, which impacts very negatively on the costs and real accessibility of Geographic Information (GI). A solution to these problems may be enrichment of geographical data by semantically well-defined metadata and widespread implementation of Spatial Data Infrastructures (SDI) as foreseen, for example, within the context of the Infrastructure for Spatial Information in Europe (INSPIRE) initiative, allowing extensive GI reuse.

INSPIRE
Leveraging the accessibility and reusability of geographic information has led to numerous activities throughout Europe to create SDIs. SDI projects occur at very regional up
to pan-European level; an example of the latter is INSPIRE. Some projects are intended only to solve data-access problems within specific areas of application, and far from all such projects have a cross-border dimension. Activities and initiatives implemented to foster and promote the establishment of SDI face many obstacles, organisational, technolo­gical and legal; and there are cultural and linguistic barriers.

Best Practices
Analysis of existing barriers to Europe-wide use of digital GI content led to the conclusion that an effective European Community debate must result in enforcement of available local and regional best practices in GI interoperable solutions and these be translated and disseminated as co-ordinated and continent-wide action. Increasing standards of quality in geographical information must be largely demonstrated by available best practice regarding how to enrich GI with semantically well-defined metadata to allow widespread reuse. This learning, swapping of experience and how to meet challenges posed by SDI at sub-national level is the aim of the eSDI-Net+ initiative, a thematic network co-funded by the eContentplus Programme of the European Commission.

eSDI-Net+ Network
The objective of eSDI-Net+ is to bring together existing SDI key players and target users within a Thematic Network established as a platform or communication and exchange between them. The network promotes Europe-wide decisions, as well as sub-national, national and regional discussion and information exchange to raise awareness concerning the importance of GI enrichment and SDI for GI reuse. The overall aim is to allow integration of expert views and permit creation of integrated guidelines, standards and implementation of best practices.

Significant results have been achieved towards characterisation of existing European SDI implementations. In 2008 and 2009 the Network identified more than 170 working, accessible and intelligible solutions. To analyse and assess these, the eSDI-Net+ consortium (see Figure 1) developed a unique SDI assessment methodology which considered cultural, technical and legal differences between European countries and provided a common evaluation framework applicable for European SDI.

Evaluating SDI
After an initial evaluation of the applications, a number of promising SDIs were selected for detailed interview to provide further information. Each interviewed SDI was evaluated by the national representatives of the eSDI-Net+ project, focusing on key aspects such as:
- technological, innovative level and originality of the project
- implementation and/or readiness for INSPIRE principles
- level of fostering co-operation between different users (proof of visibility and/or user feedback)
- possibility of extension or transfer to other countries and regions.
All Spatial Data Infrastructures in Europe were invited to submit best practices and participate in the fast growing network of SDIs.

SDI Workshops
In 2008 and 2009, twelve national and regional SDI Best Practice workshops were organised throughout Europe, focusing on common issues, usability and socio-economic impact of SDI, and addressing integration between SDI and e-government policies. They brought together stakeholders, showed case studies and discussed SDI related questions. A complete set of data obtained during identification and analysis of promising European SDI solutions was collected and documented in a database of good practices. A public version of this database will soon be available at the project website (1). To summarise the workshop results: promising solutions from different European regions were recommended for further assessment with a final goal of presenting developments for the European SDI Best Practice Award.

Award Winners
Twelve outstanding SDIs presented their solutions, focusing on the key factors in their success. Besides the provision of viewing services, information exchange with the user community and free-of-charge data, speakers emphasised the need to start small and grow up fast. "Don't think that you can provide the final solution on one day," warned Steve Brandwood of the UK, and he recommended, "start to build up a small corner. The users will validate it by its application and give you their feedback. So you can start on working on the next step."

The eSDI-Net+ award ceremony was the outcome of two momentous developments in the SDI field over recent years. The first of these is the accelerated diffusion of SDIs throughout the world over the past ten years. As a result, most countries in Europe have now taken steps to implement components of a national SDI. The INSPIRE initiative has played an important role in promoting this process of diffusion within Europe, but similar developments have taken place throughout the world.

The second momentous event is the shift in emphasis in the field from national (strategic) SDI to sub-national (operational). Whereas a great deal of previous discussion revolved around the concept of national SDI, much more time is currently being spent in discussing different ways of sub-national execution, and success at sub-national level has become a crucial yardstick of overall SDI success.

Great Diversity
Presentations at the eSDI-Net+ conference in Turin at the end of November 2009 highlighted the diversity of current practice at regional and local level within Europe and raised some important questions about the nature of SDIs. While some presentations dealt with the classic case of a SDI as translated from national administrative level to regional, most did not easily fit this model. This was particularly true of thematic SDIs that are often limited to key aspects of national SDIs.

Given the differences between selected SDIs, the jury decided that all selected were winners in terms of their own best practices, and that it would be invidious to select overall winners from such a diverse group. Thus all twelve SDIs were celebrated with the award of a Certificate of Excellence at the end of the conference; official confirmation that they had been highly commended by an international jury as one of twelve examples of best practice in Europe (see Figure 2).

On From Here
Next steps will aim at promoting the good practices in existing, working, accessible and intelligible solutions, and at communicating the purpose and aims of the INSPIRE directive back to local and regional levels. his should help improve overall knowledge concerning SDI, and encourage local collaboration in setting up innovative solutions. urther information about the shortlisted SDIs and a detailed jury report are available at the eSDI-Net+ website.

The eSDI-Net+ European Network on Geographic Information Enrichment and Re-use stands for Network for promotion of cross-border dialogue and exchange of best practices on Spatial Data Infrastructures throughout Europe.