珠江口咸潮入侵分析与经验模型——以磨刀门水道为例

Saltwater intrusion analysis and experiential model for Pearl River estuary,south China:A case study in Modaomen watercourse

收集了2004—2006年珠江口磨刀门水道咸潮发生时测站（1-7）逐日定时观测的的含氯度、水位与流量数据，分析了各监测站含氯度与水位的日变化与年变化，导出了咸潮演变各过程中，含氯度与径流、潮流、河口地形等的关系式，建立了珠江口地区磨刀门水道咸潮入侵的经验模型。据此，模拟了2006年1月12日的磨刀门地区的咸潮入侵态势，经过和沿途各观测点验证发现与实测数据非常吻合。以含氯度等于250mg／L（饮用水的含氯度最大值）的点作为咸潮入侵的最远点，用简化修改后的盐度模拟模型计算了磨刀门咸潮入侵最大距离，并根据2006年1月12～20日的河口含氯度与最近的上游天河站的径流量实测数据计算出相应的咸潮入侵最大距离。研究表明，在河流枯水期（珠江河口通常是12月至翌年3月），只要获得当天河口的含氯度和上游测站的径流量数据，就能利用此经验模型估算出河流各点的含氯度，作出盐度模拟图，并估算出相应的咸潮入侵最大距离。

Chlorosity, water level and river runoff from each saltwater intrusion observation station are collected in recent years （2004- 2006） in Modaomen watercourse of Pear River Estary, south China, when the saltwater intrusion occurs. The daily and monthly change of chlorosity and water level at the observation stations are analyzed. The correlations among salinity, runoff, estuarine chlorosity and the geometry of estuary are analyzed synthetically, and the model formula between salinity and other hydrological factors （runoff, geometry of estuary and Kx） are deduced. Then, the simulation model for saltwater intrusion length from river mouth in Modaomen watercourse is established. Finally, the simulation values of the saltwater intrusion of Modaomen watercourse on January 12, 2006 are calculated based on the model and are very close to the observed values of field. Thus, the maximum length （chlorine： 250 mg/L, upper limit of drinking water） based on the modified model parameters of salinity. So, in the dry season （usually last can provide decision making of the saltwater intrusion is calculated December to next March）, the model for quick reaction to saltwater intrusion event, and the corresponding measures can be early adopted and the disaster of saltwater intrusion is able to be expected and reduced to the minimization.