Video‐monitoring of wood discharge: first inter‐basin comparison and recommendations to install video cameras. Issue 10 (22nd June 2020)

• Record Type: Journal Article
• Authors: Ghaffarian, Hossein; Piégay, Hervé; Lopez, Diego; Rivière, Nicolas; MacVicar, Bruce; Antonio, Aurelie; Mignot, Emmanuel
• Is Part Of: Earth surface processes and landforms. Volume 45:Issue 10(2020)
• Page Start: 2219
• Page End: 2234
• Publication Date: 2020-06-22
• Subjects: Streamside video monitoring -- River monitoring -- Wood flux -- Wood discharge; Geomorphology -- Periodicals; 551.4
• DOI: 10.1002/esp.4875
• Languages: English
• ISSNs: 0197-9337

Abstract

Abstract: Wood in rivers plays a major role both ecologically and morphologically. In recent decades, due to human activities in the river channels and along the riparian zone, wood obstruction and jamming has exacerbated flooding hazards and infrastructure damage. Therefore, it is necessary to quantify the wood flux and discharge in rivers to improve wood hazard management. Among the various methods for monitoring the wood flux in a river, the streamside videography technique is effective given its high temporal and spatial resolution. Previous work monitored the wood discharge (m 3 /s) using this technique in the Ain River (France) during three floods (MacVicar and Piégay, 2012), and the same method is implemented on the Isère River (France) to obtain the statistics of wood discharge for two floods. Comparison between the two sites supports the generalization of both the monitoring technique and the link between wood discharge and flood characteristics. We first show that the maximum wood discharge is observed at bankfull discharge, and we confirm the three stage model proposed by MacVicar and Piégay (2012). Additionally, transverse distributions of the number of wood pieces and corresponding wood length appear to be similar for different flood magnitudes on each site. As a technical contribution, the use of the same technique on two sites allows for recommendations on key decisions related to the location and implementation of the equipment. Both statistical and technical contributions can be used by decision makers to implement this monitoring technique, acquire the wood transport parameters, and evaluate the potential wood hazards at local scale or along a river. © 2020 John Wiley & Sons, Ltd. Abstract : Floating wood flux is monitored by video on two sites on the Ain and Is?re Rivers, France. The interriver comparison provides a better understanding of the link between wood regime and flood characteristics and some recommendations for installing and calibrating equipment and applying this monitoring technique on different rivers.