珠江三角洲咸潮灾害主因分析

从上世纪90年代末开始，咸潮灾害在河流枯水期频繁侵袭珠江三角洲近河口地区，给1500万人口的生活和生产用水造成了很大的困难。咸潮灾害发生前和发生时期进行的大规模采掘河沙活动使三角洲河床普遍大幅度下切，河流水位下降，潮汐作用相对增强，这是引发成潮的主要原因；而天旱和海平面上升等则使咸潮灾害加重。在防御咸潮灾害的指导思想和措施上，应特别重视引发咸潮的主因。

Main cause analysis of saline water intrusion into Pearl River Delta

The disaster of saline water intrusion has arisen continually at stream outlet area of the Pearl River Delta from the end of 1990 s, which has brought on lack of water supply to fifteen millions people. According to the data analysis, the large scale and continuous excavating sand from the riverbed, which has caused the riverbed downcutring, water level decline and relative strengthening of tidal action, is the basic and main cause that raises the saline water intrusion in the Peal River network area,but the arid climate and the sea level rise only aggravate the disaster. So the main cause could not be ignored theoretically and actually in the disaster prevention and control.