珠江口盐水入侵预测模式研究

摘要

With the rapid development of economy of the Pearl River Delta,saline intrusion becomes more and more serious, which affects water extraction as well as industry and agriculture. In this paper, a sim-ple and effective prediction model is derived for saline intrusion at high slack water. By analyzing the mea-sured data with the linear regression method, the mixing coefficient Dx can be obtained, and the salinity and salt intrusion length can be calculated with it. The prediction model is validated in Modaomen estuary, one of estuaries of the Pearl River Delta in south China, and the results agree with the measured data well by analyzing the errors between them with Chi-square test. Analyzing the relationship between the salt intrusion length and tidal range,it is concluded that the optimal time of increasing runoff discharge to pre-vent saline intrusion is 2 to 3 days before neap tide,which offers a theoretical foundation for preventing sa-line intrusion.%随着珠江口地区经济的迅速发展，盐水入侵日益严重，不仅影响到周边城市的淡水供应，也为工农业生产带来了不必要的损失。基于前人研究成果，推导了一种简单有效的盐水入侵预测模式。该预测模式首先通过对现有的水文资料做线性回归分析，反演出河道的扩散系数Dx，再将Dx代入预测模式，即可计算出河道沿程的盐度值和盐水入侵距离。为了检验该预测模式，利用磨刀门2005年1月19日至2月4日的水文实测资料，就磨刀门的盐水入侵情况进行模拟，并采用卡方拟合优度检验法分析预测误差，结果表明该盐水入侵预测模型在磨刀门具有适用性。最后，通过分析磨刀门地区盐水入侵距离与潮差的响应关系，得出小潮前2~3d为增大压咸流量的最佳时机这一结论，可为“咸害”的防治提供理论依据。