Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.jes.2023.06.025
Licence creative commons licence
Title (Primary) Optimizing selective withdrawal strategies to mitigate hypoxia under water-level reduction in Germany's largest drinking water reservoir
Author Mi, C.; Rinke, K.; Shatwell, T.
Source Titel Journal of Environmental Sciences
Year 2023
Department SEEFO
Language englisch
Topic T5 Future Landscapes
Supplements https://ars.els-cdn.com/content/image/1-s2.0-S1001074223002760-mmc1.docx
Keywords Hypoxia; Water-level reduction; Hypolimnetic water withdrawal; Stratification phenology; Water quality simulation; Sediment oxygen demand
Abstract Water-level reduction frequently occurs in deep reservoirs, but its effect on dissolved oxygen concentration is not well understood. In this study we used a well-established water quality model to illustrate effects of water level dynamics on oxygen concentration in Rappbode Reservoir, Germany. We then systematically elucidated the potential of selective withdrawal to control hypoxia under changing water levels. Our results documented a gradual decrease of hypolimnetic oxygen concentration under decreasing water level, and hypoxia occurred when the initial level was lower than 410 m a.s.l (71 m relative to the reservoir bottom). We also suggested that changes of hypoxic region, under increasing hypolimnetic withdrawal discharge, followed a unimodal trajectory with the maximum hypoxic area projected under the discharge between 3 m3/sec and 4 m3/sec. Besides, our results illustrated the extent of hypoxia was most effectively inhibited if the withdrawal strategy was applied at the end of stratification with the outlet elevation at the deepest part of the reservoir. Moreover, hypoxia can be totally avoided under a hybrid elevation withdrawal strategy using surface withdrawal during early and mid stratification, and deep withdrawal at the end of stratification. We further confirmed the decisive role of thermal structure in the formation of hypoxia under water-level reduction and withdrawal strategies. We believe the conclusions from this study can be applied to many deep waters in the temperate zone, and the results should guide stakeholders to mitigate negative impacts of hypoxia on aquatic ecosystems.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=27197
Mi, C., Rinke, K., Shatwell, T. (2023):
Optimizing selective withdrawal strategies to mitigate hypoxia under water-level reduction in Germany's largest drinking water reservoir
J. Environ. Sci. 10.1016/j.jes.2023.06.025