镭、氡同位素示踪调水调沙对黄河口水体运移及营养盐分布特征的影响

Using natural radium and radon isotopes trace the water transport process and nutrients distribution in the Yellow River Estuary under the influence of the Water-Sediment Regulation Scheme

为研究调水调沙影响下的镭、氡同位素和营养盐在黄河口的分布特征,于2013年7月调水调沙期间在黄河口及其邻近海域进行了多点的连续观测。研究发现:(1)黄河口海域镭、氡同位素分布呈现明显的"分区"现象,南北两区分别为"调水调沙影响非显著区域"和"调水调沙影响显著区域",北部海域镭、氡同位素浓度高值主要来源于陆源输入(包括河流输入和海底地下水排放);(2)调查期间,北部海域水体年龄为(2.9±1.6)d,南部海域水体年龄为(5.0±2.1)d;水龄随潮汐变化表现出涨潮时水龄增大、落潮时水龄减小的波动趋势;(3)北部海域溶解无机氮(DIN)和溶解硅(DSi)含量明显高于南部海域,而溶解无机磷(DIP)在两个区域的含量相差不大。

In order to study the distribution of radium isotopes,radon isotopes and nutrients under the influence of the Water-Sediment Regulation Scheme（WSRS）in the Yellow River Estuary.We carried out 24htime-series observations at several stations in the estuary and coastal areas in July 2013.The results indicate that：（1）the distributions of radium isotopes and radon isotopes at south side were both different from which in the north side of the estuary,leading the estuary to be divided into two zones.The north zone was under a remarkable influence of WSRS and the south zone was under little influence of WSRS,respectively.High concentrations of radium and radon isotopes in the north zone were mainly due to terrestrial input,such as river discharge and submarine groundwater discharge.（2）Water ages in the north zone was（2.9±1.6）d,which in the south zone was（5.0±2.1）d.Water ages increased with rising tide and decreased with falling tide.（3）Dissolved inorganic nitrogen（DIN）and dissolved silicate（DSi）distribution also showed zonation characteristics,which concentrations were significantly higher in north area.The concentrations of dissolved inorganic phosphorus（DIP）,however,were not distinct in the whole study area.