Impact of Low-Head Dam Removal on River Morphology and Habitat Suitability in Mountainous Rivers

Yun Lu, Wan-Yi Zhu, Qing-Yuan Liu, Yong Li (), Hui-Wu Tian, Bi-Xin Cheng, Ze-Yu Zhang, Zi-Han Wu, Jie Qing, Gan Sun and Xin Yan
Additional contact information
Yun Lu: State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
Wan-Yi Zhu: Chengdu Xingcheng Capital Management Co., Ltd., Chengdu 610000, China
Qing-Yuan Liu: State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
Yong Li: State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
Hui-Wu Tian: Yangtze River Fisheries Research Institute of Chinese Academy of Fisheries Science, Wuhan 430223, China
Bi-Xin Cheng: Shanghai Investigation, Design and Research Institute Corporation Limited, Shanghai 200434, China
Ze-Yu Zhang: State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
Zi-Han Wu: State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
Jie Qing: Shanghai Investigation, Design and Research Institute Corporation Limited, Shanghai 200434, China
Gan Sun: China Three Gorges Construction (Group) Co., Ltd., Chengdu 610041, China
Xin Yan: Shanghai Investigation, Design and Research Institute Corporation Limited, Shanghai 200434, China

IJERPH, 2022, vol. 19, issue 18, 1-18

Abstract: Dam removal is considered an effective measure to solve the adverse ecological effects caused by dam construction and has started to be considered in China. The sediment migration and habitat restoration of river ecosystems after dam removal have been extensively studied abroad but are still in the exploratory stage in China. However, there are few studies on the ecological response of fishes at different growth stages. Considering the different habitat preferences of Schizothorax prenanti ( S. prenanti ) in the spawning and juvenile periods, this study coupled field survey data and a two-dimensional hydrodynamic model to explore the changes in river morphology at different scales and the impact of changes in hydrodynamic conditions on fish habitat suitability in the short term. The results show that after the dam is removed, in the upstream of the dam, the riverbed is eroded and cut down and the riverbed material coarsens. With the increase in flow velocity and the decrease in flow area, the weighted usable area (WUA) in the spawning and juvenile periods decreases by 5.52% and 16.36%, respectively. In the downstream of the dam, the riverbed is markedly silted and the bottom material becomes fine. With the increase in water depth and flow velocity, the WUA increases by 79.91% in the spawning period and decreases by 67.90% in the juvenile period, which is conducive to adult fish spawning but not to juvenile fish growth. The changes in physical habitat structure over a short time period caused by dam removal have different effects on different fish development periods, which are not all positive. The restoration of stream continuity increases adult fish spawning potential while limiting juvenile growth. Thus, although fish can spawn successfully, self-recruitment of fish stocks can still be affected if juvenile fish do not grow successfully. This study provides a research basis for habitat assessment after dam removal and a new perspective for the subsequent adaptive management strategy of the project.

Keywords: dam removal; fish reproduction; habitat suitability; morphology; assessment (search for similar items in EconPapers)
JEL-codes: I I1 I3 Q Q5 (search for similar items in EconPapers)
Date: 2022
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1660-4601/19/18/11743/pdf (application/pdf)
https://www.mdpi.com/1660-4601/19/18/11743/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jijerp:v:19:y:2022:i:18:p:11743-:d:917678

Access Statistics for this article

IJERPH is currently edited by Ms. Jenna Liu

More articles in IJERPH from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().