摘要
珠江每年输出口门的泥沙有7098×104t。近20年,东四口门的分沙比从47 7%增大为56 8%,加速了伶仃洋的淤积。东四口门的年均淤积量、水域缩小面积、滩涂自然增长率都比西四口门的大。珠江河口滩涂的年均增长量为630hm2。滩涂年均围垦面积,除1984～1988年为900hm2外,都比自然增长量小。1996年珠江河口滩涂面积为5 47×104hm2。口门整治规划实施后,可围垦滩涂约7×104hm2。
In the last twenty years the proportions of both the flow and stream load of the four eastern river mouths to those of the total eight mouths in the Zhujiang Delta increased, respectively, by 10 percentage points. The annual amounts increase were in correspondence with the total annual flow and stream load of the Beijiang River. That accelerated the accumulation process in the Lingdingyang——the estuary into which the four eastern rivers empty. The annual amount of accumulation in the four eastern mouths was 2.4 times that in the four western ones. During 1977-1999, the reduction value of sea area in the Lingdingyang estuary was 1.7 times that in the Modaomen estuary. The advance rate of the plain along the west coast of the Lingdingyang was 156m/a, while that in the Modaomen estuary of 130m/a. The natural increase rate of the tidal flat in the Zhujiang estuaries was 630 hm^2/a during 1949-1996.The increase rate of tidal flat in the Lingdingyang was 6.4 times that in the Modaomen. In the Lingdingyang the advance rate of its west shallows was 25 times that of its east shallows. The reclaimed areas in the Zhujiang estuaries during 1949-1996 totaled 4.59×10~4hm^2, of which 41% were in the Lindingyang. The reclamation rate was 900 hm^2/a during 1984-1988, much higher than the natural accumulation rate, which was only 357 hm^2/a during1986-1996. In 1996, there were 5.47×10~4hm^2 of reclaimed tidal flat in the Zhujiang estuaries, accounting for 23% of the total reclaimed area of Guangdong Province. It is estimated that a total area of 7×10~4hm^2 could be reclaimed in the tidal flats of Guangdong after implementation of the dredging programme, in which 2.67×10~4hm^2 would be in the Lingdingyang. Therefore, the potentiality to exploit the tidal flat resource would be great in the Zhujiang estuaries.
出处
《热带地理》
2004年第2期97-102,共6页
Tropical Geography
基金
国家自然科学基金项目(40371015)
广东省自然科学基金项目(2001281)资助
关键词
滩涂资源
珠江河口
Tidal flat resouce
Zhujiang estuary
