Browsing by Author "Fu, Xudong"
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Item Amplification of downstream flood stage due to damming of fine-grained rivers(2022) Ma, Hongbo; Nittrouer, Jeffrey A (TTU); Fu, Xudong; Parker, Gary; Zhang, Yuanfeng; Wang, Yuanjian; Wang, Yanjun; Lamb, Michael P; Cisneros, Julia; Best, Jim; Parsons, Daniel R; Wu, BaoshengRiver dams provide many benefits, including flood control. However, due to constantly evolving channel morphology, downstream conveyance of floodwaters following dam closure is difficult to predict. Here, we test the hypothesis that the incised, enlarged channel downstream of dams provides enhanced water conveyance, using a case study from the lower Yellow River, China. We find that, although flood stage is lowered for small floods, counterintuitively, flood stage downstream of a dam can be amplified for moderate and large floods. This arises because bed incision is accompanied by sediment coarsening, which facilitates development of large dunes that increase flow resistance and reduce velocity relative to pre-dam conditions. Our findings indicate the underlying mechanism for such flood amplification may occur in >80% of fine-grained rivers, and suggest the need to reconsider flood control strategies in such rivers worldwide.Item Impact of golden mussel (Limnoperna fortunei) colonization on bacterial communities and potential risk to water quality(2022) Zhang, Jiahao; Xu, Mengzhen; Sun, Luo; Reible, Danny (TTU); Fu, XudongMussel colonization can affect the water quality through restructuring nearby bacterial communities. In this study, we conducted an experiment to detect the bacterial alteration associated with live and dead golden mussel colonies, and used a high-throughput sequencing method based on 16S rRNA genes to reveal the changes in bacterial communities. It is revealed that these bacterial assemblages consumed nutrients and/or tissues of the mussels and produced metabolites, resulting in poor water quality and low bacterial alpha-diversities, particularly in dead mussel groups. The dissimilarity of bacterial community among the live and dead mussel groups was more significant than that among the different initial water qualities, indicating that mussel colonization and living status dominates the bacterial community. Co-occurrence network analysis revealed that the bacterial community associated with live mussel colonies exhibited more intensive interactions compared to that associated with dead ones. Furthermore, phenotype prediction indicated that mussel colonies, especially the dead mussel colonies, promoted the growth of pathogenic bacteria. Amino acid metabolism and carbohydrate metabolism were dominant pathways relevant to metabolism, leading to off-odors and the production of toxic compounds. The effect of these processes on water quality suggests that mussels that might be killed in water diversion projects should be removed promptly to avoid impacts on water quality.