Monitoring Riverbank Erosion in Mountain Catchments Using Terrestrial Laser Scanning

Abstract

Sediment yield is a key factor in river basins management due to the various and adverse consequences that erosion and sediment transport in rivers may have on the environment. Although various contributions can be found in the literature about sediment yield modeling and bank erosion monitoring, the link between weather conditions, river flow rate and bank erosion remains scarcely known. Thus, a basin scale assessment of sediment yield due to riverbank erosion is an objective hard to be reached. In order to enhance the current knowledge in this field, a monitoring method based on high resolution 3D model reconstruction of riverbanks, surveyed by multi-temporal terrestrial laser scanning, was applied to four banks in Val Tartano, Northern Italy. Six data acquisitions over one year were taken, with the aim to better understand the erosion processes and their triggering factors by means of more frequent observations compared to usual annual campaigns. The objective of the research is to address three key questions concerning bank erosion: "how" erosion happens, "when" during the year and "how much" sediment is eroded. The method proved to be effective and able to measure both eroded and deposited volume in the surveyed area. Finally an attempt to extrapolate basin scale volume for bank erosion is presented.

Case Study: Effects of a Partial-Debris Dam on Riverbank Erosion in the Parlung Tsangpo River, China

“…Without addressing these challenges, any framework aimed at providing quick assessments of the threat posed by partial-debris dams remains a scientific challenge. Therefore, a continuous monitoring method surveyed by multitemporal terrestrial laser scanning [44][45][46] is required in the future to obtain a detailed erosion profile over time immediately after the debris event. Furthermore, optical fiber sensors for the simultaneous measurement of hydrostatic pressure in soil embankments is another useful technology that can help obtain changes in the water table and also any seepage effect [47].…”

Generation of a Design Flood-Event Scenario for a Mountain River with Intense Sediment Transport

“…Sediment may be supplied by different sources, which may contribute to the total yield of the basin (e.g., [23]). Hillslope erosion [24], bank erosion [25], and concentrated sources [26] are the main contributors. This study conceptually considered the contribution of distributed erosion and scattered, local sediment sources.…”

An intensity recovery algorithm (IRA) for minimizing the edge effect of LIDAR data

“…Geometric information obtained from laser scanners is commonly used in many distinct research domains to estimate volumes, to characterize geometric features, to measure deformations, and to detect changes like accumulation or loss of material [Scaioni et al, 2013;Lindenbergh and Pietrzyk, 2015;Longoni et al, 2016]. In each field, methodological approaches have been developed to cope with specific features and problems [Pirotti et al, 2013].…”