瓯江滩坑水库建库前后盐水入侵研究

Variety Location of Saltwater Intrusion after the Tankeng Reservoir Built in the Oujiang River

随着人口的增加,工农业生产的发展,瓯江河口地区淡水资源的充分利用愈显重要。因此,研究河口地区盐水入侵的规律尤为迫切。咸水上溯距离除与下游潮汐大小有关外,还和上游来水量大小密切相关。通常枯水期咸水上溯较远,丰水期反之。拟建的滩坑水库位于瓯江小溪上,经水库调节后,径流的年际、年内分配将趋于均衡,特别是枯水期水量明显增加。针对瓯江河口的特性,采用丹麦DHI公司Mike11软件建立了一维水流盐度模型,分析计算了枯水期建库前后入侵点位置的变化、可引水时间的增加,并提出在江南位置增建翻水站的建议。研究表明,滩坑水库的建成将增加枯水期上游来水量,使盐水入侵点下移,从而提高河口区淡水资源利用率。

With the increase in population, the development of industry and agriculture, it is more and more important to make the best use of freshwater resources in the estuary area of the Oujiang River. Thus, it is emergent to study the saltwater intrusion principle. The distance of saltwater intrusion is badly affected by the upstream discharge besides out-sea tide. Ordinarily, the distant of saltwater intrusion is long in low water period and short in high water period. The planning theTankeng Reservoir is to be located on Xiaoxi site. With the reservoir regulation, the upstream discharge tends to be equilibrium within one year and in different years, especially increasing in low water periods. One-dimensional model of tidal currents and salinity is built with Mikell developed by DHI. This paper not only analyzes and calculates the variety location of saltwater intrusion, water-diversion time increasing in low water period, but also suggests a new pump station be built in Jiangnan site. It shows that upstream discharge will increase in low water period if the Tankeng Reservoir is built, the location of saltwater intrusion will shift downward and the utilization of water resources is improved.