May 12, 2024 | Li He, Yu-qi Shan, Chao Liu, Hui Cao, Xing-nian Liu, Yakun Guo
This study investigates the prediction of bedload transport inside vegetation canopies with natural morphology, which is more complex than in non-vegetated channels due to the influence of vegetation-generated turbulence. The researchers measured bedload transport rates within P. australis, A. calamus, and T. latifolia canopies and compared them with those in arrays of rigid cylinders. They found that the primary driver of bedload transport in natural canopies is the near-bed turbulent kinetic energy (TKE), which includes both bed-generated and vegetation-generated turbulence. A method was proposed to predict the near-bed TKE in canopies with natural morphology. The study also modified four classic bedload transport equations (Meyer-Peter-Müller, Einstein, Englund, and Dou equations) to account for the near-bed TKE. The results showed that for the same solid volume fraction of plants, the transport rate in canopies with natural morphology is greater than or equal to that in rigid cylinder arrays, depending on the plant shape. The Meyer-Peter-Müller equation was found to be the most accurate in predicting transport rates in vegetated landscapes. This study highlights the significant impact of plant morphology on transport rates in vegetated regions, emphasizing the need to consider natural vegetation in predictive models.This study investigates the prediction of bedload transport inside vegetation canopies with natural morphology, which is more complex than in non-vegetated channels due to the influence of vegetation-generated turbulence. The researchers measured bedload transport rates within P. australis, A. calamus, and T. latifolia canopies and compared them with those in arrays of rigid cylinders. They found that the primary driver of bedload transport in natural canopies is the near-bed turbulent kinetic energy (TKE), which includes both bed-generated and vegetation-generated turbulence. A method was proposed to predict the near-bed TKE in canopies with natural morphology. The study also modified four classic bedload transport equations (Meyer-Peter-Müller, Einstein, Englund, and Dou equations) to account for the near-bed TKE. The results showed that for the same solid volume fraction of plants, the transport rate in canopies with natural morphology is greater than or equal to that in rigid cylinder arrays, depending on the plant shape. The Meyer-Peter-Müller equation was found to be the most accurate in predicting transport rates in vegetated landscapes. This study highlights the significant impact of plant morphology on transport rates in vegetated regions, emphasizing the need to consider natural vegetation in predictive models.