建设没冒沙生态水库,开拓上海市新水源 (Ⅱ)南汇东滩淡水资源的年度分布规律

Proposal to Build Meimaosha Reservoir as A New Water Resource of Shanghai (Ⅱ) The Rule of the Fresh Water on the Nanhui East Shoal over a Year

经过南汇东滩为期1 a的水体盐度监测,了解了当地淡水资源的年度分布规律.统计结果表明,洪季和枯季的淡水出现几率分别为76.98%～82.94%、35.04%～42.66%。说明洪季有足够的淡水,即季节性的淡水,而枯季也有时段性的淡水,如果充分利用季节性和时段性的淡水, 是可以满足建设水库的淡水需求的.大通流量对南汇东滩淡水资源起决定性的作用.但值得注意的是,在大通流量<100003/s时,仍然有时段性的淡水出现,南汇东滩的淡水资源可能还受风向、地形、科氏力等的影响.经过计算,还给出了大通流量和淡水资源的关系式.

In order to understand the rule of the fresh water on the Nanhui east shoal, we have monitored the salinity over a year. After calculating, we know the percentage of the fresh water in the wet season and dry season is from 76. 88 to 82. 94 percent and from 35. 04 to 42. 66 percent respectively. If the seasonal and discontinuous fresh water resource is used efficiently, it will supply enough fresh water to the reservoir. The water discharge at Datong hydrometric station plays an important role to the fresh water on the Nanhui east shoal. We shall pay more attention to that there is fresh water when the water discharge at Datong station is less then 10,000 m3/s. The fresh water is affected by other factors such as wind, landform, Coriolis force etc. This paper gives the equations that represent the relationship between the discharge at the Datong station and the fresh water resource.