II. THE ENVIRONMENTAL MONITORING SYSTEM IN SHANGHAI
B. The network of environmental monitoring
1. Surface water quality monitoringThe key water areas monitored are the Huangpu River and its upper branches (the Taipu River, the Damao River, the Yuanxie River and the Dianshan Lake), the Suzhou River and the estuary of the Yangtze River. These are either important water sources or rivers flowing through the downtown area. Other rivers receiving regular monitoring are the Yunzaobang River, the Taopu River, the Hongkou River, the Yangpu River and the Qiu River in the urban area. Those in the suburbs are the Dianpu River, the Dazhi River, the Lianqi River, the Chuanyang River, the Pudong Canal, the Suitang River, the Nanheng Canal and the secondary and tertiary branches of the Huangpu River.
In observance of the Specifications of Environmental Monitoring Techniques
issued by the National Environmental Protection Agency in 1986, all the
monitoring sections along rivers have three vertical lines for sampling
water which are 0.5m below the surface. In monitoring lakes, different
sites are selected to sample water 0.5 m below the surface. Six sections
are fixed for the Huangpu River, six for the Suzhou River, 13 monitoring
sites are located at different parts in the Dianshan Lake, and five sections
with 13 sampling sites are positioned at the estuary of the Yantgtze River.
The remainder may be seen at table 1.
Figure 12. Shanghai Coordinating Meeting on UECH
Table 1. The monitoring sites of surface water in Shanghai
The frequency of sampling is six times per year, twice each in the rainy, regular and dry- seasons respectively. During each sampling, four water samples are collected at different tidal levels. But this specification also varies according to differing purposes. For example, the sections at the Linjiang and Songpu Bridges in the Huangpu River are for monitoring the water source of Shanghai, so daily monitoring is carried out. As the key objective of the comprehensive environmental control or harnessing of Shanghai, the urban sections in the Suzhou River are also given dense monthly monitoring. At the estuary of the Yangtze River, such frequency reduces to only one sampling every rainy, regular and dry season. The sampling, storage and indoor analysis of the water samples all follow the pertinent specifications. Automatic sampling (as well as manual) is applied at the Songpu Bridge section, while all others sections and sites use manual sampling.-
In addition to surface water quality monitoring, biological monitoring and floor-silt analysis are applied to some important water areas. The former, including zooplankton, phytoplankton, floor-rest creatures and their residual toxins, chlorophyll and biological mutation, is carried out at the Dianshan Laite, the tidal flat at the Yangtze River estuary, and the Linjiang and Songpa Bridge sections in the Hoangpo River, while the latter, mainly on heavy metals, is undertaken in the Hoangpu River and at the sub-tidal area of the Yangtze River estuary.-
The variables of surface water quality monitoring are divided into two
categories - basic and ordinary. The former is carried out in each monitoring
process which comprises temperature, pH, DO, chloride, CODMn, CODcr, BOD5,
nitrogen ammonia, nitrogen nitrite, nitrogen nitrate, volatile phenols,
petroleum and total nitrogen. In the Dianshan Lake, additional variables
such as total phosphorous and transparency are included. The latter is
generally carried out twice a year, including suspended particles, total
hardness, cyanides, As, Hg, Ca, Cr6+, Cd, Pb, Zn, Mn, conductance, anion