湖泊科学2026，Vol.38Issue(3)：1021-1032,12.DOI:10.18307/2026.0322
黄河小浪底水库水沙调控对其下游氮迁移转化及通量的影响
Impacts of the water-sediment regulation scheme at Xiaolangdi Reservoir on nitrogen mi-gration,transformation,and flux in the lower Yellow River
摘要
Abstract
To investigate the impacts of the Xiaolangdi Reservoir's regulated water and sediment releases on nitrogen migration,transformation,and flux to the sea in the lower Yellow River,surface water samples were collected six times in 2023 from two hydrological stations—Huayuankou(HYK)near the reservoir outlet and Lijin(LJ)near the river mouth—covering the periods be-fore,during,and after the water-sediment regulation event.Measured parameters included river discharge,suspended sediment con-centration(SSC),total nitrogen(TN),and dissolved and particulate nitrate nitrogen(NO3--N),ammonium nitrogen(NH3-N)con-centrations,and nitrate isotopic composition(δ15N-NO3-and δ18O-NO3-).During the water regulation stage,discharges at HYK and LJ increased to maxima of 4560 and 3690 m3/s,respectively.TN concentration decreased due to the release of clear water,while dissolved NO3--N increased and particulate NO3--N decreased.Concurrently,818O-NO3-values declined in the dissolved phase,and particulate NH3-N concentration exhibited an initial rise followed by a decline.These patterns suggest that the large discharge flushed external nitrogen into the river,stimulating mineralization and nitrification that raised dissolved NO3--N levels.Concurrently,sediment resuspension caused by the scouring flow released NH3-N into the water column,with further mobilization of NH3-N from suspended particles as regulation progressed.During the sediment regulation stage,discharges at HYK and LJ first peaked at 4010 and 3480 m3/s,then fell to 591 and 726 m3/s,respectively,while SSC increased markedly to maxima of 53.3 and 31.6 g/L.Concentrations of TN,NO3--N,and NH3-N in both dissolved and particulate phases decreased significantly from the pre-to post-sediment regulation period,with a more pronounced reduction in NO3--N at LJ than at HYK.Compared to the water regulation stage,particulate δ15N-NO3-increased during sediment regulation,and its values rose along the flow path alongside de-creasing particulate NO3--N concentrations,indicating the coupling of nitrification and denitrification.Based on TN flux estimates at LJ,the flux to the sea was highest during the post-water regulation stage(1867 t/d),followed by the pre-sediment(1724 t/d)and pre-water regulation stages(1102 t/d).These findings provide a scientific basis for understanding how water-sediment regula-tion influences nitrogen cycling and export in the lower Yellow River.关键词
水沙调控/氮/稳定同位素/耦合硝化—反硝化作用/黄河下游/水浪底水库Key words
Water and sediment regulation/nitrogen/stable isotopes/coupled nitrification-denitrification/lower Yellow River/Xiaolangdi Reservoir引用本文复制引用
李艳利,高凯洋,任世航..黄河小浪底水库水沙调控对其下游氮迁移转化及通量的影响[J].湖泊科学,2026,38(3):1021-1032,12.基金项目
水资源与水电工程科学国家重点实验室开放基金项目(2022SWG01)资助. （2022SWG01）
