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Methods11 th International Symposium for GIS and Computer Cartography for Coastal Zones ManagementThe resolution of the sample datasets is based on 1x1 km grid squares giving rise to 1,476,384,886 grid cells andfile sizes above 5 GB. To deal with the large size of the global datasets, the R statistical programming language andthe 'raster' package (Hijmans and van Etten, 2012) were used to analyse the large global grids. A meaningful goalfor the analysis was to examine the relationship between cumulative human impacts offshore and terrestrial urbanization,thereby indicating whether areas of development pressure in the oceans are related to terrestrial development.We established the hypothesis that there is a significant difference in human impacts between urban and non-urbancoastlines. To test this hypothesis, we examined the difference in the distributions for offshore human impacts alongurban and non-urban coasts using a two-sample Kolmogorov-Smirnov test, limiting our analysis to grid-cells within200 km of the coast. Urban coasts are defined as ocean grid cells which are within a 3x3 window of an urban settlement,as defined by the urban extents data grid, whereas non-urban coasts are those that are beyond the 3x3 window.While limiting our analysis to near-shore grid cells may limit the scope of our analysis, this provides an indication ofthe difference between urban and non-urban coastal areas and respective spatial development offshore, providing astatistical explanation for the patterns shown in Figure 1. Indeed, despite the significant decrease in sample size inducedby considering near-shore grid cells, both samples include well over 180,000 grid cells, providing enoughpower to detect any meaningful differences between them. Further analysis would be required to provide us with acausal relationship between terrestrial urbanization and offshore human impacts, but the analysis moves towardsexploring the spatial relationships between these data and indicating the significance of the spatial variations in marinedevelopment (Stojanovic and Farmer, 2013).ResultsFigure 1. Terrestrial urbanisation and marine development for Western Europe (Sources: based on Halpern et al. 2008; CESIN etal. 2011).63