Green Volume 2010

Methodology

To calculate the green volume, the adjusted data sets of vegetation heights were intersected with the ISU5 areas (block, block segments and road areas) (intersections formed, Figure 2) and the vegetation data was transferred to the ISU5 areas by area.

Green volume of blocks, block segments and road areas

Each ISU5 area was used to trim each corresponding vegetation area. The area size of the trimmed vegetation area was then multiplied by its mean height (Figure 2) (= green volume of a trimmed vegetation area).

The sum of these for each ISU5 area yields the green volume of all individual blocks, block segm**ents and road areas (m³). Dividing the green volume by the respective area sizes (m²) then results in the respective green volume number for each area (m³/m²).

The green volume number also serves as the mean vegetation height relative to the entire block / block segment or the non-built-up parts of the block / block segment or road area (m).

Fig. 2: Method for calculating the green volume (top left: ortho-photo with block boundaries; top right: vegetation areas with block boundaries; bottom: trimmed vegetation areas and legend)

Green volume of non-built-up parts of block and block segment areas

To determine the green volume of non-built-up block areas, the ALK buildings above ground (main and auxiliary buildings) were first assigned to their respective areas. These buildings were then used to trim the individual areas.

The vegetational stock assigned to the areas extend beyond the non-built-up parts (vegetation in road areas, canopies above building level and green roofs).

Trimming the vegetation share based on the non-built-up areas yields the desired vegetation of the non-built-up block and road areas (Figure 3).

The green volume was calculated further according to the process described above.

Fig. 3: Method to calculate the green volume of non-built-up block areas (top left: block area; top right: buildings above ground; centre left: non-built-up block area (grey share); centre right: vegetation cover; bottom: vegetation of the non-built-up block area)