Large wood (LW) refers to downed, dead wood exceeding 1 m in length and 0.1 m in diameter, playing a vital role in natural river ecosystems. When transported in rivers, large wood interacts with one another and with flow, sediment, and river boundaries, leading to their physical degradation. This degradation, causing mass of loss and changing of the geometry of the wood, is relevant to various fluvial processes, including bed morphology evolution, aquatic habitat variation, changes to the local environment, and the carbon cycle.

Current studies have largely focused on large wood transport, the formation of logjams, and the bio-chemical degradation of smaller wood components (such as sticks and leaves) within aquatic habitats. However, little is still known about the physical degradation process of large wood, which significantly affects wood transportation, logjam formation and failure, and aquatic habitats.

Here we first introduce a laboratory-based tumbling machine experiment to investigate the abrasion process of large woods during river transport. Several tests considering river energy, wood characteristics and wood-sediment-river boundary interactions will be conduct to analyze the wood degradation pattern and mechanism. This project aims to offer preliminary insights into the mechanisms underlying wood degradation in rivers.