III. ENVIRONMENT MONITORING AND URBAN PLANNING
F. The comprehensive environmental harnessing of the Suzhou River
1. The Suzhou River
The Suzhou River is the important surface water source of Shanghai. It originates from the Tai Lake, flowing from Guajingkuo of Wujiang County in Jiangsu Province eastward through Wujiang County and Kunshan Town in Suzhou City, Qingpu County, Minhang District (the former Shanghai County), Jiading District (the former Jiading County), Putuo District, Changning District, Jing'An District, Zhabei District, Hongkuo District and Huangpu District of Shanghai City, then pours into the Huangpu River at the Waibaidu Bridge. It is 125 km long in total, 53.1 km in Shanghai, 22 km inside the city (towards Huacaogang). -
The Suzhou River is the front part of the Yangtze Delta, the topography of the river basin being flat and the fall of the watercourse being small. Because of the large curvature, its shape is tortuous. The Suzhou River is remarkably influenced by the tide. There are flood-tides and ebb-tides respectively twice every day. The runoff of the river has the characteristics of reciprocation, which has a very long time lag, so the net flow of the river inside the city is very small and there is almost no runoff of the river during the arid season. Because of this, the Suzhou River has long lost its function of draining out the flood of the Tai Lake basin, which was taken over by the Huangpu River. If it is polluted, it would not be able to regain its former cleanliness easily because its ability to self-purify is weak.
Some characteristics and functions of the Suzhou River have been very seriously damaged because of both historical and present-day events and developments. Its environmental quality has become totally unacceptable, and the river now contains all manner of industrial pollutants and living waste matter. Moreover, it also carries a very heavy burden of water transportation and has been badly polluted by the refuse and waste matter from these vessels and docks.
Since 1949, many new industrial zones such as Beixinjing, Pengpu, Taopu and An'ting have blossomed alongside the river and its branches and the number of residents has increased to more than 300 million. With housing and industries concentrating on chemicals, printing and dyeing, cotton -weaving, paper-making, leather-making and food and drugs springing up, the volume of human and industrial waste water, pesticides and chemical fertilizers being discharged into the Suzhou River has gradually increased. Before the Project of Shanghai Urban Sewage Discharges into the Donghai Ocean, was put into operation, the sewage of the river accounted for 47 per cent of the total sewage of the whole city. The quantity of sewage discharged into the river in 1985 was concentrated in the reach towards Beixinjing. The proportion of waste matter in this portion of the river accounted for 71.1 per cent of the total, yet the length of this reach is only 30 per cent of the 54 km length flowing through the city. Pollution of the water has become more and more serious and the polluted area is gradually moving upstream as a result of the increasing polluting sources. In 1956, it reached Beixinjing, then came to Huacao 8 years later and then reached Baihe and Zhaotun of Qingpu in 1978, by which time the course of the Suzhou River within the Shanghai region was polluted entirely. According to the water quality statistics of a 5--year average level based on data from 1986 to 1990 (according to the classification standard of the surface water environmental quality in Shanghai), there is only one segment ion that meets the 4th level - the Baihe segment ion. The Huangdu segment ion is at the 5th level (heavily polluted) and the segment ions below Huacao are all at the 6th level. When we compare the main pollutants of 1993 with that of 1992, we find that pollution of the Suzhou River decreased a little, but pollution in 1994 was about the same as that in 1993. -
In recent years, as Phase I of the Shanghai Sewage Project and the Shanghai Environmental Protection Regulations have been put into effect, Shanghai has made some progress in managing the old pollution sources and controlling new ones. Most industrial and living pollution sources of the Suzhou River east to Beixinjing within the Shanghai region have been brought into the service range of the Project, which has considerably reduced the volume of pollutants discharged into the Suzhou River. But improvement of the water quality of the Suzhou River has been less than complete and successful because of economic development and a higher living standard, which result in even heavier pollution.