n this study, erosion experiments were conducted using vegetated plots with four species of emergent vegetation and bare-soil plots in a recirculating flume. To investigate the effects of emergent vegetation on soil erosion in riparian regions, erosion topography and eroded soil mass were obtained using laser-scanned images, and root system development of the emergent plants was analyzed by measuring root parameters after the root washing process. The results showed that Cyperus malaccensis (i.e., shortleaf galingale) demonstrated the highest survival rate and developed the longest root system. The vegetated plots with Typha orientalis (oriental cat-tail), C. malaccensis, and Ludwigia octovalvis (lantern seedbox (H)) exhibited smaller eroded soil masses than did the bare-soil plots. C. malaccensis and L. octovalvis exhibited higher erosion resistance than the other species because the vegetated plots with these species exhibited less soil loss than the plots with the other species, and the plants exhibited greater development of root systems than the other species. Considering the survival rate, C. malaccensis was the most suitable species among the four species for increasing erosion resistance of riverbanks in riparian regions.
Keywords: Soil erosion, emergent vegetation, root system length, laser-scanned topography