Response of eutrophication development to variations in nutrients and hydrological regime : a case study in the Changjiang River (Yangtze) Basin

Tang, X; Li, R; Han, D; Scholz, M

Abstract

Data and literature related to water quality as well as nutrient loads were used to evaluate the Changjiang River (also Yangtze or Yangzi) Basin with respect to its hydrological regime, sediment transport, and eutrophication status. Waterbodies exhibited different eutrophic degrees following the ranking order of river reservoir lake. Most of the eutrophic lakes and reservoirs distributed in the upstream Sichuan Basin and Jianghan Plain are located in the middle main stream reaches. During the past decade, the water surface area proportion of moderately eutrophic lakes to total evaluated lakes continually increased from 31.3% in 2009 to 42.7% in 2018, and the trophic level of reservoirs rapidly developed from mesotrophic to slightly eutrophic. Construction and operation of numerous gates and dams changed the natural transportation rhythm of runoff, suspended solids (SS), and nutrients, and reduced flow velocity, resulting in decreased discharge runoff, slow water exchange, and decreased connectivity between rivers and lakes as well as accumulated nutrient and SS, which are the main driving forces of eutrophication. To mitigate eutrophication, jointly controlling and monitoring nutrient concentrations and flux at key sections, strengthening water quality management for irrigation backwater and aquaculture wastewater, and balancing transportation among runoff, SS, and nutrients is recommended.

Citation

Tang, X., Li, R., Han, D., & Scholz, M. (2020). Response of eutrophication development to variations in nutrients and hydrological regime : a case study in the Changjiang River (Yangtze) Basin. Water, 12(6), e1634. https://doi.org/10.3390/w12061634

• Journal Article Type: Article
• Acceptance Date: Jun 5, 2020
• Publication Date: Jun 7, 2020
• Deposit Date: Jun 10, 2020
• Publicly Available Date: Jun 10, 2020
• Journal: Water
• Publisher: MDPI
• Volume: 12
• Issue: 6
• Pages: e1634
• DOI: https://doi.org/10.3390/w12061634
• Keywords: eutrophication, phosphorus, suspended sediment, reservoir, regulation, water resources’ management
• Publisher URL: https://doi.org/10.3390/w12061634
• Related Public URLs: https://www.mdpi.com/journal/water
• Additional Information: Additional Information : ** From MDPI via Jisc Publications Router ** Licence for this article: https://creativecommons.org/licenses/by/4.0/ **Journal IDs: eissn 2073-4441 **History: published 07-06-2020; accepted 05-06-2020; Funders : National Natural Science Foundation of China;Outstanding Young Talents of National High-level Personnel of the Special Support Program;China Three Gorges Corporation; Grant Number: 51979006 and 41907401; Grant Number: CKSD2019542/SH; Grant Number: 201903145