JultikaUniversity of Oulu repository

Abstract

As the availability of open spatial data is increased, its use in various fields in working life has become more common. Posiva uses GIS in the biosphere assessment to produce projections of the development of the surface environment and ecosystems of Olkiluoto. Biosphere assessment is part of the safety case programme for assessing long-term safety and its purpose is to characterise the development of the surface environment and its conditions in the past, present and in the future at the Olkiluoto site and assess the radiological impacts in the surface environment during the assessment time frame. In former studies, Posiva has used open spatial data in the biosphere assessment as supplements in creating maps modelling the development of the Olkiluoto surface environment.

This study examined the new approaches to utilising open spatial data in surface environment characterisation, from a perspective of long-term safety case. The objective was to discover the features that are possible to represent with open spatial data. The work was conducted with the commercial ArcGIS programme application ArcMap 10.6 using only open spatial data.

The model characterisations were created from the Olkiluoto, Hanhikivi and Kivetty sites on their soil types, biotope types and land use, catchment areas, water quality and watersheds. The topics were selected according to the previous surface environment studies conducted by Posiva and the results of this study were compared to the results of previous characterisations conducted at the Olkiluoto site and its surrounding areas.

The results indicated that open spatial data can be utilised in characterising the surface environment and it is possible to partially replace other survey methods. The quality of open spatial data varied from very detailed to very coarse. The most informative characterisations were terrain maps, soil type and sea sediment maps, and biotope and land use maps as the data was the most detailed. When observed together these maps provided even more information.

As open spatial data can be produced by anyone, it is advisable to be aware of the producers when using the data. The data owned and produced by public administration are more reliable than the data produced and provided by an individual user of GIS.