Extraction of Wind Erosion Obstacles by Integrating Gis-data and Stereo Images

Data integration is a very important strategy to obtain optimum solutions in geo-scientific analysis, 3D scene modelling and visualization. This paper mainly focuses on the integration of GIS-data, stereo aerial imagery and DSM to derive automatically wind erosion obstacles in the open landscape to enhance the Digital Soil Science Map of Lower Saxony in Germany. The extracted wind erosion obstacles can be used to derive wind erosion risk fields for soil monitoring and preservation. GIS-data is used as prior information for the object extraction. The GIS-objects roads, field boundaries, rivers and railways from GIS database can represent initial search areas for extracting wind erosion obstacles, which are often located parallel and near to them. Wind erosion obstacles are divided in the semantic model into hedges and tree rows, because of different available information from the GIS-data, although their extraction strategies are similar. Different approaches, such as segmentation by NDVI and CIE L*a*b, edge extraction, linking, grouping and verifying with 3D information, are combined to extract the objects of interest. The extracted wind erosion obstacles are integrated into a semantic model, described by their 3D appearance in geometry, together with 2D elongated shadow regions in a known direction according to 3D information and sunshine.