Explanatory Notes on Main Statistical Indicators

Production Capacity of Water Supply refers to the designed overall production capacity of water facilities, covering the four segments of water collection, purification, conveyance, and outflow through trunk pipelines. Increased capacity through transformation and innovation projects is included as well. The capacity is determined mainly on the weakest of the above-mentioned four segments.

Length of Water Supply Pipelines at Year-end refers to the total length of all the pipelines between the water pumps and the user water meters, excluding pipelines newly installed but not used yet, pipeline in the water factory,and pipeline in the user’s buildings.

Annual Volume of Water Supply refers to the total volume of water supplied by water-works (units) during the reference period, including both the effective water supply and loss during the water supply.

Consumption of Water for Residential Use refers to water consumption of households for daily life and water consumption of public service facilities. The latter refers to water consumption for urban public services, including the consumption of government agencies and public institutions, military barracks, public facilities, wholesale and retail outlets, restaurants, hotels, and other units providing public services. Household water consumption refers to consumption of water for daily life of all households within the boundary of cities, including households of urban residents and farmers, and public water supply stations.

Coverage Rate of Urban Population with Access to Tap Water refers to the ratio of the urban population with access to tap water to the total urban population. The formula is:

Production Capacity of Gaswork Gas refers to the overall production capacity of the urban gasworks in gas generation, purification and delivery at the end of the reference period, excluding capacity of the reserved facilities. In general, it is determined by the designed capacity, and when actual production capacity is larger than the designed capacity, the capacity is determined by the actual measurement on the weakest segment in the production, purification and delivery.

Length of Gas Pipelines refers to the total length of pipelines in use between the outlet of the compressor of gas-work or outlet of gas stations and the leading pipe of users, excluding pipelines within gasworks, delivery stations, LPG storage stations, refilling stations, gas-mixing stations and supply stations.

Volume of Gas Supply refers to the total volume of gas provided to users by gas-producing enterprises (units) in a year, including the volume sold and the volume lost.

Coverage Rate of Urban Population with Access to Gas refers to the ratio of the urban population with access to gas to the total urban population at the end of the reference period. The formula is:

Heating Capacity in Urban Areas refers to the designed capacity of heating enterprises (units) in supplying heating energy to urban users during the reference period.

Quantity of Heat Supplied in Urban Areas refers to the total quantity of heat from steam and hot water supplied to urban users by heating enterprises (units) during the reference period.

Length of Urban Heating Pipelines refers to the total length of steam or hot water pipelines for sources of heat to the leading pipelines of the buildings of the users, excluding internal pipelines in heat generating enterprises.

Length of Paved Roads at Year-end refers to the length of roads with paved surface including bridges and tunnels connected with roads by the end of the year. Length of the roads is measured by the central lines for vehicles for paved roads with a width of 3.5 meters and over, including roads in open-ended factory compounds and residential quarters.

Urban Bridges refer to bridges built to cross over natural or man-made barriers, including bridges over rivers, overpasses for traffic and for pedestrians, underpasses for pedestrians, etc. Both permanent and semi-permanent bridges are included.

Length of Urban Sewage Pipes refers to the total length of general drainage, trunks, branch and inspection wells, connection wells, inlets and outlets, etc.

Daily Disposal Capacity of Urban Sewage refers to the designed 24-hour capacity of sewage disposal by the sewage treatment works or facilities.

Number of Vehicles under Operation at Year-end refers to the total number of vehicles under operation by public transport enterprises (units) at the end of the year, based on the records of operational vehicles by the enterprises (units).

Area of Parks and Green Land refers to the total area occupied for green projects at the end of the reference period, including park green land, production green land, protection green land, green land attached to institutions, and other green areas.

Park Green Area refers to green areas open to the public for amusement and rest with the facilities of amusement, rest and services. Its function includes perfecting ecology, beautifying landscape, and preventing and reducing disaster. Park green areas include comprehensive park, community park, topic park, belt-shaped park and green area nearby street. Total areas of comprehensive park, topic park and belt-shaped is the area of park.

Area Cleaned refers to the area which are regularly cleaned, as at the end of the reference period, at urban roads and public places (mainly including urban roadways, pedestrian walkways, vehicular tunnels, pedestrian underpasses, underground railway stations, lifted roads, pedestrians walk bridges, overpasses, plazas, carparks and other facilities). If there are several times of cleaning in a day at a location, the area of that time of cleaning with the largest area cleaned will be taken.

Vehicles Dedicated to Urban Cleanliness and Environmental Sanitation refer to vehicles and facilities dedicated for use in the operation, management and monitoring of environmental hygiene work. They include vehicles for road cleaning, washing, showering, ice removal, disposal of garbage and human wastes, cleanliness monitoring and related activities.

Public Transportation Vehicles per 10000 Population refers to the number of public transportation vehicles, at the end of the reference period, per 10000 population in the city district. The formula for calculation is:

Waste Water Discharged by Industry refers to the volume of waste water discharged by industrial enterprises through all their outlets, including waste water from production process, directly cooled water, groundwater from mining wells which does not meet discharge standards and sewage from households mixed with waste water produced by industrial activities, but excluding indirectly cooled water discharged (It should be included if the discharge is not separated from waste water).

Industrial Waste Water Meeting Discharge Standards refers to volume of industrial waste water discharge which, with or without treatment, reaches national or local standards with regard to all pollutants.

Urban Non-industrial Waste Water Discharge refers to annual discharge of non-industrial waste water by urban households. It is estimated by per capita coefficient using the formula:

Volume of Chemical Oxygen Demand (COD) Generated by Urban Non-industrial Waster Water refers to chemical oxygen demand generated through the annual discharge of non-industrial waste water by urban households. It is estimated as:

Chemical Oxygen Demand (COD) refers to the amount of oxygen required when chemical oxidants are used to oxidize organic pollutants in water. A higher value of COD corresponds to more serious pollution by organic pollutants.

Industrial Waste Air Emission refers to the discharge into atmosphere of waste air containing pollutants generated from fuel burning and production processes in enterprises within a given period of time. It is calculated at standard status (273K, 101325Pa) as:

SO2 Emission through Non-industrial and Other Activities is calculated on the basis of consumption of coal by households and other activities and the sulphur content of coal with the following formula:

SO2 Emission through Industrial Activities refers to volume of sulphur dioxide emission from fuel burning and production process by enterprises during a given period of time. It is calculated as:

Industrial Soot Emission refers to the volume of soot in smoke emitted in the process of fuel burning in the premises of enterprises.

Soot Emission by Consumption and Others refers to the net volume of soot emitted by fuel burning from all social and economic activities and operations of public facilities other than industrial activities. It is calculated on the basis of coal consumption by households and others.

Industrial Dust Emission refers to volume of dust emitted by production process of enterprises and suspended in the air for a given period of time, including dust from refractory material of iron and steel works, dust from coke-screening systems and sintering machines of coke plants, dust from lime kilns and dust from cement production in building material enterprises, but excluding soot and dust emitted from power plants.

Industrial Solid Wastes Produced refers to total volume of solid, semi-solid and high concentration liquid residues produced by industrial enterprises from production process in a given period of time, including hazardous wastes, slag, coal ash, gangue, tailings, radioactive residues and other wastes, but excluding stones stripped or dug out in mining - gangue and acid or alkaline stones not included (a stone is acid or alkaline according to the pH value of the water being below 4 or above 10.5 when the stone is in, or soaked by water).

Hazardous Wastes refers to those included in the national hazardous wastes catalogue or specified as any one of the following properties in the national hazardous wastes identification standards: explosive, ignitable, oxidizable, toxic, corrosive or liable to cause infectious diseases or lead to other dangers.

Industrial Solid Wastes Utilized refers to volume of solid wastes from which useful materials can be extracted or which can be converted into usable resources, energy or other materials by means of reclamation, processing, recycling and exchange (including utilizing in the year the stocks of industrial solid wastes of the previous year). Examples of such utilizations include fertilizers, building materials and road materials. The information shall be collected by the producing units of the wastes.

Rate of Utilization of Industrial Solid Wastes refers to the percentage of industrial solid wastes utilized over industrial solid wastes produced (including stocks of the previous years). It is calculated as:

Stock of Industrial Solid Wastes refers to the volume of solid wastes placed in special facilities or special sites for purposes of utilization or disposal. The sites or facilities should take measures against dispersion, loss, seepage, and air and water contamination.

Industrial Solid Wastes Disposed refers to the quantity of industrial solid wastes which are burnt or placed ultimately in the sites meeting the requirements for environmental protection and not salvaged or recycled (including disposition in the year of those wastes of previous years). The disposition includes landfill (Safe landfills should be conducted for hazardous wastes), incineration, containment spaces, deep underground disposal, backfill in mining pits and disposal at sea.

Industrial Solid Wastes Discharged refers to the volume of industrial solid wastes discharged by producing enterprises to disposal facilities or to other sites. The wastes exclude stones stripped or dug from mining (gangue and acid or alkaline waste stones not included).

Output Value of Products Made from Waste Gas, Waste Water and Solid Wastes refers to the current value of products with waste gas, waste water and solid wastes as main materials of production. Products sold and ready to sell shall be included while those produced for own use shall not be included.

Consumption Wastes Transported refers to volume of consumption wastes collected and transported to disposal factories or sites. Consumption wastes are solid wastes produced from urban households or from service activities for urban households, and solid wastes regarded by laws and regulations as urban consumption wastes, including those from households, commercial activities, markets, cleaning of streets, public sites, offices, schools, factories, mining units and other sources.

Ratio of Consumption Wastes Treated refers to consumption wastes treated over that produced. In practical statistics, as it is difficult to estimate, the volume of consumption wastes produced is replaced with that transported. It is calculated as: