东线南水北调对黄浦江水质的影响

IMPACTS OF WATER TRANSFER FROM SOUTH TO NORTH ON THE WATER QUALITY OF THE HUANGPU RIVER

本文对长江枯季(12—3月)径流的特点、变化规律、河口盐水入侵以及对黄浦江水质的影响等进行了初步分析。 长江水量虽然丰富,但枯季径流并不大,枯季径流一般占年径流总量的15％左右。频率50％的平水年各月平均流量都在15000秒立米以下,频率75％的一般少水年枯季1、2月份的月平均流量不足10000秒立米。河口盐度变化随上游来水多少而异,大通站流量在10000秒立米时河口盐度变化敏感,流量再减少河口盐度将急剧增加,便会严重污染河口和黄浦江水质,影响上海市和河口地区的工农业和城市生活用水。因此,在规划长江流域用水时,应使大通站流量在15000秒立米以上,若有困难,至少不能低于10000秒立米。

This paper gave a preliminary analysis of the characteristic and vari ation regularity of runoff of the Yangtze river in low-flow period (from Dec. to Mar.) , and the effects on the quality of the water of the Huang pu river after the intrusion of sea water.Although rich in water resource the Yangtze river hasn’t much discharge during the low-flow period. The total runoff in low-flow period occupies only fifteen per cent of the annual total runoff. The mean monthly discharge in low-flow period of normal year of 50% frequency is below 15000 M3/sec. The mean monthly discharge of 75% frequency of dry year in Jan.and Feb, is less than 10000 M3/sec. Salinity varies with the quantity of the flow which comes from upstream. It becomes highly sensitive in river-mouth area when the discharge in Da Tong station is 10000 M3/sec. The salinity in river-mouth area will increase repidly if the discharge in Da Tong station is less than 10000 M3/sec. As a result, serious impacts will happen to the water supply both of Shanghai city and the industrial and agricultural bases in river-mouth area. For the planning of water supply in the Yangtze river basin,it is necessary to keep the discharge through Da Ton station above 15000 M3/sec, or at least not less than 10000 M3/sec.