长江流域发展对长江口水域功能开发的影响

EFFECT OF DEVELOPMENT IN THE YANGTZE BASIN ON THE EXPLOITATION OF THE WATER FUNCTION IN THE MOUTH OF THE YANGTZE RIVER

长江口水域是上海市重要水源地,同时兼具工农业取水、通航、纳污、围垦等多种功能,长江口已成为上海市建设世界级城市的重要支撑之一,其水资源的开发、利用和保护已成为人们关注的焦点。重点分析了随着长江流域社会经济的发展,流域水旱灾害、水土流失、污染物排放、大型水利工程建设等因素对长江口水域功能的影响,提出长江口现状过境水资源量为9335×108m3/a,上海市最大可开发利用的资源量约在3680×108m3/a;长江口水域水质基本符合II类标准,但近岸水域的污染不容忽视;长江口咸潮入侵成为长江口水资源利用的最大障碍,每年长江口的氯化物超标天数在45d;长江流域的来沙量有减少的趋势,多年平均输沙量为4.35×108t。最后,就河口水域功能开发提出了相关对策建议。

The mouth of Yangtze River is one of the main water source of Shanghai City,and is the major supply of water for industry and agriculture,navigation and even for admitting pollutants.The river mouth has been one of the important factors for Shanghai to be a modern and international metropolis.The development,utilization and conservation of the river mouth has become the wide concern of the society.With the social and economical development in the Yangtze Basin,the flood and drought disasters,the soil and water erosion,and the pollutant discharge and the construction of the large hydraulic projects have influenced the water function in the mouth of the Yangtze.It is proposed that the actual quantity of the transit water resource is about9335 × 10 8 m 3 /a,and the most exploitable quantity for Shanghai city is about3680 × 10 8 m 3 /a.The water quality of the mouth of the Yangtze River must meet the environmental quality standard II for surface water.But,the coast pollution cannot be overlooked.The salinity intrusion in the mouth of the river has become the obstacle for the water resource,with average number of days exceeding the chloride standard is45each year.The incoming sediment has gradu - ally decreased and the mean annual sediment discharge is4.35 × 10 8 t/a.Suggestions were then made on the de - velopment of water functions in the mouth of the Yangtze River.