Tillämpning av GIS-analyser i MKB

Sammanfattning: The reason for performing an Environmental Impact Assessment (EIA) is to incorporate environmental concern in different kinds of plans and projects. The purpose of such an assessment is to identify and describe direct, indirect and cumulative environmental impacts. Geographical Information System (GIS) is a tool that can be used to combine spatial extension of both sensitive areas and different environmental impacts in a quick and easy way. Because of that, descriptions of environmental impacts and motivation of different standpoints on a specific issue can be more correct and easier to make if GIS is used as a tool. Hence, GIS can contribute to improve the quality of Environmental Impact Assessments. If the benefits of using GIS are to out weight the costs, geographical information of satisfactory detail, actuality and accuracy need to be available at reasonable prices. In this paper, case studies are carried out for three different geographical analyses to investigate the use of GIS as a tool in EIA. From these case studies, more general conclusions about the benefits and limitations of using GIS for Environmental Impact Assessments are also drawn. The criteria, after which benefits and limitations of GIS have been estimated, are data availability, time consumption for performing the analyses and how the results from the performed analyses can make impact assessments easier, motivate different standpoints and increase the comprehensiveness of the EIA-report. The three different GIS-analyses includes calculation of pollution load in a catchment area, estimation of the visual impact from planned buildings and generation of alternative locations for underwater pipes. These analyses have been applied on one ongoing EIA for a freight terminal and one ongoing EIA for an underwater wastewater transmission pipe. The analyses in these case studies have been undertaken with ArcGIS software using the extensions “Spatial Analyst” and “3D Analyst”. It is shown in this study that due to uncertainty in available model values and the time consuming data manipulation, it is unlikely that calculations of pollution loads with GIS will be used to any larger extent in EIA. To carry out visual assessments with help of GIS to estimate visual impacts is on the other hand assumed to be useful in EIA-work. Both to assess impacts and to estimate how changes in building design can alter those impacts. To use GIS to produce alternative locations for underwater pipes is also considered valuable in EIA-work, even though there is a considerable lack of data to predict the environmental class of marine areas and the connections between available data and real environmental values are weak. However, the risk of damaging vulnerable and high valued marine areas should decrease when applying this type of analyse.