珠江三角洲网河区水位变化趋势研究

The secular trend of water level changes in the network channels of the Zhujiang River Delta

根据珠江三角洲网河区29个验潮站的实测验潮记录,应用傅氏变换与最平滤波器串联的方法来消除月均序列的周期波动对确定水位变化趋势的影响,由低通序列一元线性回归分析确定各站水位的变化趋势;结果表明,周期波动对确定海平面变化趋势的影响是显著的.应用经验正交函数（EOF）对网河区的水位变化场进行分解,由相互独立的时间函数和空间特征函数表征网河区区域的水位变化特征;应用时间特征函数计算区域水位的平均变化率为0.02mm/a.根据验潮站的水位变化趋势,探讨网河区水位变化与河床冲淤的关系.

Considering the significant contribution of the periodic components to the secular trends of relative sea level (RSL) change, the Fourier transform and the maximum flat filter were applied to eliminate the effects of periodic components on the determination of the secular trends of RSL change. The secular trend of RSL change was determined by linear regression of low-pass series. The empirical orthogonal function (EOF) was used to analyse the characteristics of RSL change; the average rate of water level change in the Zhujiang River Delta was calculated by the main mode of EOF, which is 0.02 mm/a. According to the secular trends of gauge stations in the networks, the response of water level change to the channel degradation and aggradation was discussed.