西北江三角洲压咸流量初步研究

Research on Flow Capacity for Repelling Saltwater Intrusion in the North and West River Delta

根据西北江三角洲水文特点,以马口、三水水文站及三灶潮位站为参证水文站,以思贤滘流量(即马口水文站与三水水文站流量之和)为上游来水径流量。依据实测资料,对西北江三角洲咸潮上溯径流-咸潮响应模式、压咸流量进行了研究。研究结果表明,上游径流的减少是近几年来咸潮上溯加强的最主要因素。为保障西北江三角洲城市供水安全(氯化物(以Cl^-计)<250mg/L),在现有供水基础设施不变的条件下,西北江三角洲最小压咸流量应为2 500m^3/s。

According to the hydrographic characteristics of the North and West River delta,Makou and Sanshui hydrologic stations were taken study stations,together with Sanzao Tidal Station as references.The flow capacity of Sixianjiao(namely the sum flow capacity of Makou and Sanshui hydrologic stations)was regarded as upriver streamflow.Based on the measured data,the responded mode of streamflow-saltwater in Modaomen Channel was investigated in order to determine the flow capacity or repell saltwater intrusion.The results show that the decrease of flow capacity is the primary factor leading to serious salinity intrusion in recent years.In order to ensure the security of water supply for the North and West River delta(i.e.,keeping Chlorinityc<250mg/L),it is found that under the present conditions of infrastructure for water supply, the minimal flow capacity for repelling saltwater intrusion in the West and North River delta should be 2 500m^3/s.