The folder Lake_Points contains the different lake-shapefiles. Each file has bathymetry- and shoreline-points for the interpolation. Shoreline points have heights of 0 meter. For the interpolation we used the toolbox Spatial Analyst of ArcMap 10.2. The interpolation method we used was "natural neighbour" with a fixed resolution of 0.5m for each lake. (The suggested value of ArcMap differs for each lake and depends on user inputs which are not reproducible and the volume calculations should be comparable between the lakes.) All interpolations are calculated with positive values (column depth in the shapefiles). The resulting raster was clipped by a shoreline polygonshape, created with the shoreline points.
