Visual impact assessment of river regulation structures

Abstract

The paper presents the quantitative methodology for visual impact assessment of river regulation structures such as non-submerged groins and longitudinal dams. The method integrates LIDAR data, GIS tools, 3D graphic software and 360° panoramic images. Digital Surface Model (DSM) developed on the basis of LIDAR data and imported to 3D graphic software allows one to render images from any location of 3D scene. This feature was used for rendering 360° panoramic images from the perspective of the observers located on the study site in designated with the viewshed analysis area. Renders were verified against panoramic photographs taken during the field inspection. The proposed methodology was tested on two locations of Kostrzyn nad Odrą and Słubice cities where modernization of regulation structures on Oder River is planned. Calculated percentage values of river regulation structures occupying the full field of view of the observer for 25 locations in Kostrzyn nad Odrą and 19 locations in Słubice shows insignificant visual impact. The maximum values of 0.94% and 0.26% for Kostrzyn nad Odrą and Słubice respectively, where obtained. Additionally the visualization method in the form of “Little Planet” projections was presented, which allows for full documentation of the visual impact of the structures on the landscape.