磨刀门水道咸潮入侵及其变异分析

随着区域经济及人口的进一步增长,珠江三角洲磨刀门水道已成为江门、中山、珠海、澳门等城市重要的水源地,相应咸潮入侵对供水安全造成的危害也越来越严重。本文依据实测资料和现场调研,对磨刀门水道咸潮入侵的潮相变化、径流—咸潮的响应模式、风对咸潮入侵的影响及咸潮入侵的历史演变趋势及其变异、最小压咸流量及最佳压咸时机等进行了研究。研究结果表明,影响咸潮入侵的主要因素是径流,有利于咸潮入侵的风向为北风～东北风。以思贤滘流量(即马口水文站与三水水文站流量之和)为参照,为保障珠海、澳门供水安全,磨刀门水道最小压咸流量范围为2200-2700m3/s,平均流量为2450m3/s,最佳压咸补淡的时机为大潮转小潮期,也就是朔望(半月)周期的落潮期。

Analysis of Tidal Saltwater Intrusion and Its Variation in Modaomen Channel

With development of regional economy and population,Modaomen Channel in the Pearl River Delta has become an important water source field for the cities of Jiangmen,Zhongshan,Zhuhai and Macao.Based on the observed data and field survey,this paper researched the change of tidal saltwater,response mode of runoff and salty tide,influence of wind,trend of historic development and variations,minimum discharge for overcoming saltwater intrusion and best opportunity.The results show that runoff is the main effect on tidal saltwater intrusion with the north or northeast wind.According to calculation,the minimum discharge for overcoming saltwater intrusion should be 2 200-2 700 m3/s in Modaomen Channel,the average discharge should be 2 450 m3/s,and the best opportunity is within the ebbing tide duration in syzygy period.