Types of saltwater intrusion of the Changjiang Estuary

The Changjiang Estuary is characterized by multi-order bifurcations, unsteady submerged sandbars, mid-channel sandbars, creeks and riffles. The following four types of saltwater intrusion are found: (1) direct intrusion from the sea; (2) intrusion during tidal flooding; (3) intrusion from tidal flats overflow; and (4) salt water coming upstream through other waterways. These result in a complicated temporal and spatial salinity distribution. A high chlorinity concentration zone exists from the Liuhekou to the Sidongkou along the South Branch. The salinity during neap tide or ordinary tide is higher than during spring tide.     

水体微型颗粒的流式细胞术测定

应用流式细胞术（FCM）对水体中不同粒径级微型颗粒的数量、百分比及随时间变化进行了初步研究；仪器经流速校正，样品经过滤，外参法测定；结果表明FCM可快速、即时分析水体中的微型颗粒。     

Fluid mud transportation at water wedge in the Changjiang Estuary

In situ data show that fluid mud of the Changjiang Estuary consists of fine sediment ranging from 8 to 11.5μm (median grain-size) including 28.8%-36.4% of clay. The composition of the clay is illite, chlorite, kaolinite and montmoillonite. The FM is a layer of high sediment concentration near the bed and results from flocculation under the environment of salt and fresh water mixing. Three kinds of FM have been identified under typical dynamic conditions: the first one is formed at slack water of ebb tide during the flood season, with the characteristics of extended area and low thickness; the second one is formed following a storm, characterized by large area and larger thickness; the third one is formed around the front of the saltwater wedge, characterized by small area but large thickness. In the dredged channel, the FM can be accumulated up to 1 m thick. In general, FM will change with the alternation from spring to neap tides, flood and dry seasons. Drastic change can happen during storms. At the s     

连续不宜取水天数的预测

长江引水,使更多的上海市民能饮用长江水,市有关部门根据不断增加的用水要求,拟在长兴岛附近的青草沙建立避咸蓄淡水库,水库的容量取决于用水量和该处连续不能取到含盐度较低的长江水的天数,本文利用马尔可夫模型和线性动态模型作为估计该处连续取不到合格水的最大天数估计的数学模型,论文给出了模型的推导,计算及验证的整个过程。     

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.