Vegetation Encroachment Monitoring for Transmission Lines Right-of-Ways: A Survey

With the increasing blackouts owing to vegetation encroachments of transmission lines right-of-ways, it has become imperative for the transmission suppliers to review their transmission vegetation management practices so as to avoid further incidents of un-intended encroachment. In this paper, a comparative study, in terms of advantages and limitations, of the existing monitoring techniques for inspecting High-Voltage overhead transmission lines has been presented. Regarding the clearance of un-intended encroachments such as trees and vegetation of transmission lines right-of-ways, the surveillance of transmission lines is usually done periodically through visual inspection, or by airborne system. The Geographical Information Systems (GIS) containing the geo-referenced data of assets, lands, wherefrom the transmission lines pass are essential tools for the improvement of transmission lines maintenance. Air-borne LIDAR scanners, Videography, Multispectral Satellite images and Aerophotogranometry are now available. These tools, because of their accuracy in spatial resolution, can be applied to track not only invasions, but also monitor the vegetations surrounding the transmission lines right-of-ways.