Digital Air Photo Processing for Mapping of Copper Roof Distribution and Estimation of Related Copper Pollution

Emission of metals in the urbanenvironment is a growing concern throughout theworld. In order to identify metal emissionssources in the Stockholm metropolitan region, amethod for detailed mapping of roof coatings andother urban land covers has been developedconducted. High accuracy area calculation ofcopper roof coatings based on scanned aerialphotography was used. The geometric resolution ofthe digital photographs was 0.4 metre. Imagelayers with identified copper roof objects weremerged with a digital elevation model of 1 metregeometric resolution. The slope gradient for eachroof was calculated in order to account for slopein the calculation of roof areas. In total,622,590 m² of copper roofs were accounted,of which 176,845 m² and 447,745 m²represent new and patinated copper respectively.The number of copper roofs larger than 1,000m² was 142. Applying corrosion and runoffrates on these figures, a yearly Cu flux ofapproximately 1,200 kg in Stockholm may bederived from copper coated building.