| The variations and fluxes of dissolved inorganic nutrients were studied, based on continuously monitored data in the lower main channel of Yellow River (Lijin) during the period of water-sediment regulation in July 2002.Concentrations rang from 169.3 to 273.2 μmol·dm-3for NO-3-N, 0.08 to 0.84 μmol·dm-3 for NO-2-N, 1.39 to 5.04 μmol·dm-3 for NH+4-N, with average of 218.6, 0.16, 2.27 μmol·dm-3, respectively. Concentrations rang from 0.36 to 0.56 μmol·dm-3for PO3-4-P, 161.4 to 195.8 μmol·dm-3for SiO2-3-Si, with average of 0.48, 166.7 μmol·dm-3, respectively. No significant relationship was found between nitrate, phosphate and water discharge during the period of water-sediment regulation, while silicate correlated well with suspended sediment discharge. Water-sediment regulation has no significant effect on the variation of dissolved inorganic nutrients concentrations during 2002 to 2003. But the fluxes proportion of dissolved inorganic nutrients during water-sediment regulation to the whole year is about 50%. |
