New Article in Ecological Engineering

Volume 158, 1 December 2020, 106048

Assessment of safety-relevant woody vegetation structures along railway corridors
Stephan Hoerbingera, Michael Obriejetana, Hans Peter Raucha, MarkusImmitzerb

Railway networks are linear landscape elements that are mostly accompanied by adjacent lineside vegetation. In order to maintain safe railway operation, lineside vegetation must be continuously monitored and maintained. A large-scale assessment approach to identify safety-relevant woody vegetation structures along a railway corridor is presented in this paper. Based on accurate surface and terrain data, precise models of the lineside vegetation and the railway corridor were created for a study site. A proximity analysis was performed to assess elements of woody vegetation that are tall enough and close enough to strike the railway infrastructure in the case of failure. Information about the vegetation type and the geometric position of identified safety-relevant vegetation is provided in hazard classes. Falling curves of safety-relevant vegetation were calculated to indicate areas where trees pose a potential risk to the railway track. Analysis of datasets from 2012 and 2017 shows a dynamic development of safety-relevant vegetation along the railway corridor between the two studied years. A vegetation risk index (VRI) was calculated for the study site. Both sections of high presence and sections where safety-relevant vegetation is completely absent could be identified. The study has confirmed that airborne remote sensing technologies have great potential to provide data for large-scale lineside vegetation assessments. Through a combination of airborne laser scanning data and high resolution orthophotos, safety-relevant vegetation could be mapped successfully. The presented approach can support tree care management and contribute to maintaining safe and functional lineside vegetation.