Modeling of impervious surface in Germany using Landsat images and topographic vector data

The constant expansion of urban agglomerations in most countries is closely associated with a significant increase of impervious surface (IS). In Europe, robust and cost-effective methods for detection and quantification of IS on a continental or national scale are still rare. Thus, our study focuses on determining the percentage of impervious surface (PIS) for whole Germany based on a combined analysis of Landsat images and vector data on roads and railway networks, using Support Vector Machines (SVM) and GIS functionalities. We developed a procedure which provides functionalities for 1) the modeling of IS for built-up areas (PIS_B) based on optical earth observation data, 2) the combination of PIS_B with vector data providing additional information on small-scale infrastructure (PIS_T) and 3) the spatial aggregation of the combined product (PIS_BT) to the administrative units of municipalities. Compared to reference data sets of four cities, the results showed a mean absolute error of 19.4% and a mean standard deviation of 17.3%. The mean PIS of the total of residential, industrial and transportation-related areas in Germany comes up to 43.0%, with a minimum in the federal state of Brandenburg (39.3%) and a maximum in Hessen (46.1%).