Historical aerial photographs and digital photogrammetry for impact analyses on derelict land sites in human settlement areas

In old industrialized areas large sites of former coal and steel industries offer a great potential for internal urban development. The reuse of such derelict and mostly contaminated land requires systematic research to identify possible risks for human health and the environment. Hence a historic site investigation needs to be carried out to find possible sources of pollutants in a sites history. Besides others sources of information historical aerial photographs represent a valuable documentation about former site development. Using the example of the Ruhr District in North Rhine-Westphalia (Germany) this paper discusses the potential of digital photogrammetry for analysing historical aerial photographs as part of a historic research incorporating three-dimensional vision, direct digital mapping in stereo-models as well as the generation of elevation models