Estimation of dissolved inorganic nutrients fluxes from the Changjiang River into estuary

Because the estuary acts as either a trap or a source or both for nutrient elements and will modify greatly the riverine transport to the ocean, it is necessary to calculate the flux from river into estuary and that from estuary into sea, respectively. The present work aims to use a long-term record of nutrients concentrations and runoff discharges on H.e Datong section (625 km inland from the Changjiang River mouth) to identify the variability of nutrients concentrations and to estimate nutrients fluxes from the Changjiang River into the estuary.

长江入河口区生源要素的浓度变化及通量估算

利用近几十年长江大通断面的实测流量和生源要素 (C、N、P、Si)资料 ,讨论了C、N、P、Si较长时间序列浓度的变化特征和长江入河口区的通量。结果表明 ,HCO-3 浓度比较稳定 ,波动较小 ;NO-3 、NO-2 、PO3-4 主要呈上升趋势 ;游离CO2 、NH+4和SiO2 -3 浓度表现出一定下降趋势 ;估算并研究了长江C、N、P、Si入河口区年内各月的平均通量、年际间各年的通量和多年平均的年均通量和主要变化特征 ;利用月通量序列以及相应的流量序列 ,拟合出可以利用已知的月均流量预测进入河口区的月通量的关系函数。这些研究是进行河口区生源要素收支平衡计算的重要基础。