V. INSTITUTIONAL ARRANGEMENTS FOR ENVIRONMENTAL MANAGEMENT
F. Technology indexes and standards
5. Index system of urban comprehensive environmental quality in Shenyang
In Shenyang, the urban economy is relatively strong and the population density is relatively high; as a result, environmental pollution is serious. However, it is not easy to draw a conclusion on the comprehensive environmental quality of the whole city. Because the economy, services, culture and traffic in the city centre has improved, the environmental quality of Shenyang must be assessed from a broad perspective. The framework of the overall urban environmental quality index system of Shenyang is given in figure 29.
The index system comprises three large systems: the urban economy, urban society and urban environment. Eight subsystems are derived from the three main systems: urban scale, urban economic infrastructure, the status of vegetation cover, water quality, atmospheric quality, urban waste gases, solid wastes and environmental noise. The ractical implications of indexes are explained below.
Urban size is a major index that reflects the urban population size and land area. As a result of urban expansion, the urban population is continuously increasing and the urban boundaries are steadily expanding. Urban land size as defined here refers to built-up districts. Apart from urban population size and urban land, urban population density is a compound index reflecting urban size and is an important input in urban planning.
The urban economy reflects the development level. The major comparable index is gross national product and the next index is the structure of the three industries. The structure of three industries reflects overall economic competence. In particular, the proportion of tertiary industry is a major index that can indicate the economic strength of the city. The composition and numbers of employees in the three industries is also is an indispensable index that reflects the urban economic management level and degree of development.
Infrastructure is a major index that reflects the level of urbanization and the level of development. Infrastructure is a necessary precondition to establishing a good investment environment. It reflects the level of urban management and is related closely to the convenience and comfort of urban inhabitants. It covers many areas, especially urban road area, road length, area of housing and number of rooms per person, tap water amount per person, per capita charge for electricity, the amount of gas per person, per capita communication facilities etc.
Modern cities contain well maintained parks and numerous trees throughout the urban area. The area of urban green cover per person should reach a certain minimum standard as it helps to provide fresh air.
Urban air environmental quality is an important index that determines whether urban air is clean or harmful to human health. The main pollutants causing atmospheric environmental quality deterioration are sulphur dioxide, nitrogen oxide, suspended particles and dust.
Urban water environment is concerned with urban water sources and drainage sites. It is also concerned with urban landscape and shipping. Therefore, the urban water environment affects the quality of drinking water and is an important element of the urban environment. The main indexes include those for organic aerobic pollutants, toxic and harmful pollutants in water bodies such as biochemical oxygen demand within five days, dissolved oxygen, chemically consumed oxygen, K-nitrogen, permanganate value, total arsenic, total Cd Cr6+, volatile phenolphthalein, oil groups etc.
Urban waste mainly includes domestic garbage, human excrement and urban industrial solid waste. Those substances seriously affect urban environmental sanitation and the health of citizens. The rate of timely collection, and the rate of adequate treatment and disposal are another indication of the level of urban development.
Urban noise includes noise from industries, construction, traffic, public places etc. This index is important for ensuring quiet urban living and working conditions. Urban environmental noise is expressed by equivalent day and night noise classifications.