Annex 1. Detailed description of the input data for the aggregated pressure layers The table below gives more details to how the aggregated pressure layers included in the Baltic Sea Impact Index and the Baltic Sea Pressure Index were compiled. The table columns give: A: the identity of the aggregated pressure layer (APL); B: its temporal nature, indicating whether it represents a cumulative pressure (CUM; values over the assessment period are summed) or a temporary pressure (TEMP; average values over the assessment years are used); C : underlying spatial data sets included; D: the spatial extent applied; E: justification for spatial extent; F: data processing applid to arrive at common unit, and final metric; G: Whether down-weighting by seabed exposure and water depth was applied, and H: method for aggregating spatial data sets to one aggreatred pressure layer. *With respect to physical loss and disturbance it should be noted that whether an activity in reality leads to loss of or disturbance of the seabed depends on many factors, such as the diration and intensity of the activity, the technique used and the sensitivity of the area affected. The identification of which activities lead to loss and/or physical disturbance is still under development A. B. C. D. E. F. G. H. Pressure Underlying spatial Spatial extent Data and data Depth / datasets processing exposure layer weighting method Physical Cum Land claim Area of polygon or Estimated Calculate lost area. Not Activities loss 50 m buffer for based on In a grid cell: relevant are (permanent points, 30m buffer wind calculate combined effects on for lines turbine proportion of the and the erosion cell area. potentially seabed)* overlapping (van der areas are Wal & removed. Tamis Dataset is 2014). No clipped direct with reference. coastline. Combined Watercourse 50 m buffer as above. Calculate lost area. Not layer is modification In a grid cell: relevant intersected calculate with 1 km proportion of the grid to cell area. calculate % Coastal defence and 50 m buffer for lines, as above Calculate lost area. Not of area lost within a flood protection area of polygon In a grid cell: relevant cell. calculate proportion of the cell area. Extraction of sand and Area of polygon - Calculate lost area. Exposure gravel In a grid cell: affects calculate recovery, proportion of the but this is cell area. not included
Annex 1. Detailed description of the input data for the aggregated pressure layers The table below gives more details to how the aggregated pressure layers included in the Baltic Sea Impact Index and the Baltic Sea Pressure Index were compiled. The table columns give: A: the identity of the aggregated pressure layer (APL); B: its temporal nature, indicating whether it represents a cumulative pressure (CUM; values over the assessment period are summed) or a temporary pressure (TEMP; average values over the assessment years are used); C : underlying spatial data sets included; D: the spatial extent applied; E: justification for spatial extent; F: data processing applid to arrive at common unit, and final metric; G: Whether down-weighting by seabed exposure and water depth was applied, and H: method for aggregating spatial data sets to one aggreatred pressure layer. *With respect to physical loss and disturbance it should be noted that whether an activity in reality leads to loss of or disturbance of the seabed depends on many factors, such as the diration and intensity of the activity, the technique used and the sensitivity of the area affected. The identification of which activities lead to loss and/or physical disturbance is still under development A. Pressure layer B. C. Underlying spatial datasets D. Spatial extent E. F. Data and data processing G. Depth / exposure weighting H. method Physical loss (permanent effects on the seabed)* Cum Land claim Area of polygon or 50 m buffer for points, 30m buffer for lines Estimated based on wind turbine erosion (van der Wal & Tamis 2014). No direct reference. Calculate lost area. In a grid cell: calculate proportion of the cell area. Not relevant Activities are combined and potentially overlapping areas are removed. Dataset is clipped with coastline. Combined layer is intersected with 1 km grid to calculate % of area lost within a cell. Watercourse modification 50 m buffer as above. Calculate lost area. In a grid cell: calculate proportion of the cell area. Not relevant Coastal defence and flood protection 50 m buffer for lines, area of polygon as above Calculate lost area. In a grid cell: calculate proportion of the cell area. Not relevant Extraction of sand and gravel Area of polygon - Calculate lost area. In a grid cell: calculate proportion of the cell area. Exposure affects recovery, but this is not included