Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1080/20442041.2024.2305105
Title (Primary) Nutrient retention in a small reservoir under changed variability of inflow nutrient concentration
Author Determann, M.; Musolff, A.; Frassl, M.A.; Rinke, K.; Shatwell, T.
Source Titel Inland Waters
Year 2023
Department SEEFO; HDG
Volume 13
Issue 4
Page From 560
Page To 575
Language englisch
Topic T5 Future Landscapes
Supplements https://ndownloader.figstatic.com/files/46160507
https://ndownloader.figstatic.com/files/46160510
https://ndownloader.figstatic.com/files/46160513
Keywords catchment–lake interaction; concentration variability; GOTM-WET; lake nutrient export; reservoir biogeochemistry
Abstract Within freshwater networks, lakes and reservoirs are reactors that modify nutrient dynamics. Their functioning is based on an interplay of hydrological and biogeochemical processes, rendering them vulnerable to climate change. Future changes in catchment characteristics are likely to alter the timing and magnitude of nutrient concentrations in discharge. This study investigated the impact of changing variability of nutrient concentrations on lake and reservoir dynamics. We examined intraannual nutrient retention and analyzed the role of reservoirs in reconfiguring the variability of nutrients. Utilizing the 1D lake model GOTM-WET, we simulated nutrient processing in a mesotrophic reservoir. Further, we performed scenario simulations by modifying the variability of inflow nitrogen and phosphorus concentrations. Our findings indicate that the reservoir removed ∼4% and ∼12% of total nitrogen (TN) and total phosphorus (TP), respectively. Particulate fractions were retained efficiently, but there was a net export of dissolved organic fractions. Regarding mixing and stratification periods, however, we observed net nitrogen export during stratification in certain years. During stratification, outflow concentration variability remained relatively unchanged for TN and TP compared to inflow concentrations. Conversely, phosphate and nitrate concentration variability increased in the outflow because of in-lake assimilation and the influence of hydrological events. With increasing inflow concentration variability during stratification, there was decreased removal of TN and TP by the reservoir, but increased variability of concentration. By evaluating the lake's capacity to attenuate variability of nutrient inflows under altered conditions, there are opportunities to improve monitoring of nutrient export and evaluate the potential impact of nutrient peaks on downstream drinking water resources and ecosystems.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=29121
Determann, M., Musolff, A., Frassl, M.A., Rinke, K., Shatwell, T. (2023):
Nutrient retention in a small reservoir under changed variability of inflow nutrient concentration
Inland Waters 13 (4), 560 - 575 10.1080/20442041.2024.2305105