Development of Quantitative Evaluation Methods for Surface Roughness and Abrasion Depth in Agricultural Open Channels

Abrasion, a major degradation of agricultural open channels, leads to a decrease in hydraulic and structural performance. To consider appropriate countermeasures in a timely manner, it is important to monitor abrasion conditions. Therefore, we propose two methods for the quantitative and nondestructive measurement of surface roughness and abrasion depth: a method using a laser displacement transducer and a method using a contour gauge. The results of monitoring the abrasion depth in agricultural open channels repaired with mortar coating materials using these methods show that the average abrasion rate is approximately 0.1 to 0.2 mm/year, and that the value varies depending on the service environment and the part of the channel (sidewall or bottom slab), even if the materials are the same. The contour gauge method tended to slightly underestimate the parameters involved in monitoring the abrasion depth compared to the laser displacement transducer.