4.1.2. Agricultural Water Consumption
Water consumption by agricultural activities is the amount of water used to produce plant and animal products. The virtual water consumption for agricultural products included water consumptions due to irrigation and soil absorption, and water consumption by animals, such as water for feeding, cleaning, and slaughter. In this study, agricultural water consumption refers to the total amount of virtual water used through the consumption of agricultural products and relevant services by inhabitants in Beijing, which can be calculated by multiplying the consumption quantity of various agricultural products by their water content factors per unit. Generally, the main sources of agricultural production in Beijing are domestic production and the net import of products from areas external to Beijing after deducting the products exported to other provinces and overseas regions. The former is the local agricultural virtual water consumption and the latter is the agricultural virtual water consumption. Due to the lack of trading statistics for agricultural products in Beijing, we had to estimate them based on the proportional relationship between the quantity of trade value and the domestic consumption value retrieved from “Beijing input–output (IO) table” [
16]. We then categorized agricultural water consumption into domestic virtual water consumption and the virtual water consumption by trade.
The data related to the water content of agricultural products was acquired from the CLIMWAT database, which is a climatic database used for the calculation of water demand, irrigation supply, and irrigation scheduling for various crops for a range of climatological stations worldwide. The database for Beijing was provided by the Food and Agriculture Organization (FAO), with reference to the calculation results of some peer studies [
17,
18] in China. The statistics reflecting the yield of agricultural products were also from agriculture and rural economy section in the Beijing statistical yearbooks in 2007 and 2010. The consumption of agricultural products can be divided into two components: urban resident consumption and rural resident consumption. The data for the rural resident can be required directly from the statistics about the daily food consumption per capita by 3000 families. However, the lack of urban resident consumption data meant that it was calculated from the expenditure on food per capita by 5000 unban families, based on the average food prices over one year. The annual prices of food products in Beijing were estimated by local annual price indices on the basis of Chinese various food products’ prices in 2012. The annual price indices in Beijing were obtained in Beijing statistical yearbook in 2007 and 2010, and the Chinese food products’ prices were obtained in China price statistical yearbook in 2013. The agricultural products were categorized into eight sectors, which were grain, vegetable and mushroom, edible oil, meat, poultry and egg, dairy product, aquatic product, and fruit. Their water footprints were calculated by the method mentioned above, and are shown in
Table 1. It is clear that the total virtual water amounts due to the consumption of agricultural products in Beijing were 159.49 × 10
8 m
3 in 2007 and 183.29 × 10
8 m
3 in 2010. According to the IO table, 61.27% and 51.46% of the agricultural products consumed were origin from net import in 2007 and 2010. Based on these percentages, the agricultural virtual water consumption by trade was 97.72 × 10
8 m
3 in 2007 and 94.32 × 10
8 m
3 in 2010 with domestic virtual water consumption being 61.78 × 10
8 m
3 and 88.96 × 10
8 m
3, respectively (
Figure 1).
Table 1.
Water consumed by the production of agriculture products in 2007 and 2010 (100 million m3).
Table 1.
Water consumed by the production of agriculture products in 2007 and 2010 (100 million m3).
Year | Grain | Vegetable and Mushroom | Edible Oil | Meat | Poultry and Egg | Dairy Product | Aquatic Product | Fresh and Dried Fruits | Total |
---|
2007 | 20.05 | 25.07 | 7.23 | 14.17 | 10.32 | 53.03 | 18.81 | 10.81 | 159.49 |
2010 | 23.83 | 29.09 | 9.61 | 15.73 | 11.77 | 61.26 | 19.36 | 12.65 | 183.29 |
Figure 1.
Virtual water consumption by local agriculture production and trade.
Figure 1.
Virtual water consumption by local agriculture production and trade.
4.1.3. Water Consumption by Industry
In the production sectors of Beijing, water consumption not only occurs during the general processes of production, but also includes water consumption by other products from external sectors, which will be consumed as an intermediate input. Therefore, these direct and indirect water consumptions should be included in the water consumption value for the sector [
19]. Considering the sector correspondence of Beijing input–output (IO) Table, the production sectors were categorized into three groups, including primary, secondary and tertiary industrial sectors in China. Given that the primary industrial sector generally refers to agricultural sector, the industrial water consumption here represents the water consumption by other industrial sectors. Different from the method used in the calculation of agricultural water consumption in the previous chapter, IO table was used in secondary and tertiary industrial water consumption, since it can specify how the water flow among sectors through supplying inputs for the outputs (where virtual water is embedded) in the Beijing economic system [
14]. Thus, an IO method analysis was applied to calculate the cumulative water utilization of each sector based on the known amount of direct water consumption. The IO analysis included input–output table data published by national or regional statistical departments (
Table 2), which reflects the constructional associations between production sectors and consumption.
Table 2.
The standard format China-IO (input–output) table for the water footprint calculation of secondary and tertiary industrial sectors.
Table 2.
The standard format China-IO (input–output) table for the water footprint calculation of secondary and tertiary industrial sectors.
| Intermediate Consumption | Final Consumption | Export | Import | Total Output |
---|
Intermediate input | xij | ƒi | ei | mi | xi |
Added value | cj | |
Total input | xj |
Water consumption | wj |
The matrix of direct consumption coefficients in each sector for 42 sectors can be set as
A, which reflects the direct consumption by external products needed for internal production:
With the exception of the direct consumption by an intermediate product, the production in a certain sector is also affected by water that is indirectly consumed by products from other sectors that have been involved in producing this intermediate product. In this study, B represents the matrix of cumulate demand coefficients, which reflects the total demand for the intermediate and additional products needed to product one unit of final product in one sector, including the amount of direct demand
A, the amount of indirect demand A
2 + A
3 + …, and the amount of final demand I. The equation related to the variables above can be written as
where
(I − A)−1 is known as the Leontief inverse matrix and
bij denotes how much production output by sector
j is required to meet one monetary unit of the final consumption of sector
i.In order to link the monetary output to water consumption, the direct water consumption coefficients are defined as the amount of direct water used to produce one monetary unit of product output, which indicates the direct water use (
d) of a sector. The matrix for direct water consumption
D is expressed as
Therefore, the matrix for cumulative water consumption can be shown as
where
vj represents the cumulative water consumption needed to produce a certain product in
j sector. In conclusion, the matrices for the water footprints caused by domestic industrial sectors can be shown as follows:
where
i is equal to
j, and
wfj represents the total water resource utilization caused by the consumption of a product from
j sector.
The virtual water resource used by trading generally refers to the virtual water used by commodities for import and export in Beijing. According to the categories of trade goods, the items with a virtual water resource consumption include primary, secondary and tertiary industrial products. Our study investigated the net virtual water inflow during the trading of secondary and tertiary industrial products, and estimated the virtual water inflow of agriculture products, which was described separately above because of the lack of actual trade statistics for agriculture products in Beijing.
The virtual water embodied in the net import of secondary and tertiary industrial products is regarded as the cumulative water consumption of products during net trade flow, which will be later consumed by inhabitants in Beijing. This part of virtual water consumption is not the real amount of water consumed by production in Beijing, but the water Beijing would consume if it had to produce a product itself instead of importing it. The equations for virtual water consumption during trading are as follows:
where
represents the sum total for imported secondary and tertiary industrial products, including the products from overseas and other provinces, and
represents the sum of exported secondary and tertiary industrial products. The net virtual water inflow of secondary and tertiary industrial products was calculated and is shown in
Table 4.
It is worth noting that IO tables for Beijing become available every five years and an extended version is available three years after publication of the original IO table. The IO table for 2012 is still unavailable, so our study adopted the IO tables for 2007 and 2010, obtained from the Beijing statistical bureau website, to calculate the water consumption by various sectors.
As the results in
Table 3 show, the virtual water resource consumed by domestic secondary and tertiary industrial sectors was 134.05 × 10
8 m
3 in 2007 and 119.04 × 10
8 m
3 in 2010; The virtual water consumption by the production of secondary and tertiary industrial products in trading was 78.84 × 10
8 m
3 in 2007 and 55.69 × 10
8 m
3 in 2010 (
Table 4). Thus, the total water footprints caused by the secondary and tertiary industrial production are the sum of the virtual water consumption by domestic production and by trading (
Figure 2).
Table 3.
The water consumptions by various industrial sectors in 2007 and 2010 (× 10 thousand m3).
Table 3.
The water consumptions by various industrial sectors in 2007 and 2010 (× 10 thousand m3).
Secondary and Tertiary Industrial Sectors | 2007 | 2010 |
---|
Direct Water Use | Cumulative Water Use | Direct Water Use | Cumulative Water Use |
---|
Secondary industry | Mining and washing of coal | 185.60 | 1163.09 | 399.76 | 949 |
Extraction of petroleum and natural gas | 6.54 | 0.00 | 136.50 | 485 |
Mining of metal ores | 1242.36 | 0.00 | 72,743.08 | 0 |
Mining and processing of nonmetal ores and other ores | 54.82 | 0.00 | 17.10 | 0 |
Manufacture of foods and tobacco | 8975.91 | 51,689.17 | 8890.61 | 38,102 |
Manufacture of textiles | 635.54 | 4669.77 | 409.05 | 5689 |
Manufacture of textile wearing apparel, footwear, caps, leather, fur, feather (down) and its products | 128.79 | 8660.71 | 224.08 | 10,871 |
Processing of timbers and manufacture of furniture | 186.49 | 4778.77 | 173.85 | 3391 |
Papermaking, printing and manufacture of articles for culture, education and sports activities | 1951.17 | 2033.83 | 1513.88 | 1924 |
Processing of petroleum and nuclear fuel, and coking | 146,905.64 | 19,712.01 | 145,789.11 | 33,571 |
Chemical industry | 72,232.88 | 25,097.15 | 91,455.63 | 27,996 |
Manufacture of nonmetallic mineral products | 7761.06 | 1042.57 | 8712.93 | 693 |
Smelting and rolling of metals | 106,653.70 | 0.00 | 12,657.95 | 0 |
Manufacture of metal products | 2267.05 | 11,112.79 | 2012.74 | 7094 |
Manufacture of general purpose and special purpose machinery | 2484.97 | 42,893.65 | 4723.29 | 57,942 |
Manufacture of transport equipment | 7559.27 | 23,419.84 | 11,765.76 | 17,270 |
Manufacture of electrical machinery and equipment | 735.89 | 22,730.48 | 764.71 | 9947 |
Manufacture of communication equipment, computer and other electronic equipment | 37,114.69 | 21,430.30 | 21,444.26 | 16,355 |
Manufacture of measuring instrument and machinery for cultural activity and office work | 633.70 | 2462.22 | 394.69 | 1419 |
Handiwork and other manufacture | 337.95 | 7812.40 | 478.20 | 6948 |
Waste disposal | 2.19 | 0.00 | 27.74 | 0 |
Production and supply of electric power and power for heat | 218,009.50 | 36,195.82 | 259,383.17 | 28,,338 |
Production and distribution of gas | 410.76 | 873.46 | 120.83 | 1671 |
Production and distribution of water | 2215.07 | 2800.55 | 7049.73 | 5301 |
Construction and other industry | 6497.21 | 6497.21 | 569,371.07 | 8229.60 |
Tertiary industry | Traffic, transport and storage | 2821.28 | 11,862.23 | 3058.09 | 10,840 |
Post industry | 188.87 | 51.53 | 182.15 | 32 |
Information transmission, computer services and software | 564.52 | 57,656.67 | 670.52 | 58,250 |
Wholesale and retail trades | 1925.66 | 12,098.52 | 2448.29 | 14,123 |
Hotels and catering services | 6083.22 | 16,972.25 | 7428.78 | 24,468 |
Financial intermediation | 646.20 | 12,711.97 | 608.13 | 22,830 |
Real estate | 5262.70 | 48,855.76 | 7003.85 | 81,214 |
Lease and commercial service industry | 2013.12 | 5690.79 | 2829.46 | 7583 |
Research and development | 1227.45 | 41,267.62 | 1276.84 | 49,350 |
Synthesis technique services | 793.88 | 32,792.66 | 918.02 | 7095 |
Water supply, environment, and public facilities management | 4915.08 | 9747.91 | 5936.51 | 8362 |
Service to households | 405.02 | 6876.16 | 379.71 | 5173 |
Education | 6917.44 | 43,683.69 | 7421.04 | 40,306 |
Sanitation, social insurance, and welfare | 2419.90 | 97,842.90 | 2740.99 | 150,620 |
Culture, sports, and entertainment | 1457.73 | 21,557.91 | 1676.58 | 20,260 |
Public management and social organization | 3005.74 | 60,840.91 | 3412.56 | 67,346 |
Total | 665,836.54 | 1,340,459.12 | 707,509.79 | 1,190,414.25 |
Table 4.
Virtual water consumption by the trade in secondary and tertiary industrial products (10 thousand m3).
Table 4.
Virtual water consumption by the trade in secondary and tertiary industrial products (10 thousand m3).
Year | 2007 | 2010 |
---|
Secondary industry | Mining and washing of coal | 8024.52 | −474.29 |
Extraction of petroleum and natural gas | 14,144.25 | 15,868.68 |
Mining of metal ores | 21,912.44 | −21,036.92 |
Mining and processing of nonmetal ores and other ores | 22,165.26 | 21,185.23 |
Manufacture of foods and tobacco | 18,083.23 | 19,378.47 |
Manufacture of textile | 7004.79 | 10,361.16 |
Manufacture of textile wearing apparel, footwear, caps, leather, fur, and feathers (down) and its products | 4019.28 | 9859.74 |
Processing of timbers and manufacture of furniture | 11,451.62 | 7599.93 |
Papermaking, printing, and manufacture of articles for culture, education, and sports activities | 35,810.59 | 28,178.07 |
Processing of petroleum, coking, processing of nuclear fuel | 134,576.48 | 63,384.70 |
Chemical industry | 98,716.46 | 96,056.17 |
Manufacture of nonmetallic mineral products | 50,831.13 | 31,388.03 |
Smelting and rolling of metals | 361,224.02 | 315,652.08 |
Manufacture of metal products | 69,917.37 | 48,511.43 |
Manufacture of general purpose and special purpose machinery | −1717.37 | 2099.94 |
Manufacture of transport equipment | −25,720.14 | −44,095.49 |
Manufacture of electrical machinery and equipment | 55,185.27 | 38,681.22 |
Manufacture of communication equipment, computers, and other electronic equipment | 41,259.88 | 61,146.87 |
Manufacture of measuring instruments, and machinery for cultural activities and office work | 6299.59 | 2620.33 |
Handiwork and other manufacture | 6207.80 | 4386.43 |
Waste disposal | 4055.45 | −164.24 |
Production and supply of electric and power for heating | 51,156.02 | 38,712.94 |
Production and distribution of gas | 1631.03 | 4601.31 |
Production and distribution of water | 17.13 | 11.81 |
Construction and other industry | 152,844.66 | −4098.74 |
Tertiary industry | Traffic, transport and storage | −51,981.97 | 93,430.83 |
Post industry | −4138.36 | −3679.97 |
Information transmission, computer services and software | −87,996.66 | −65,889.29 |
Wholesale and retail trades | −12,840.16 | −819.82 |
Hotels and catering services | −4225.98 | −1887.18 |
Financial intermediation | −41,316.14 | −66,908.97 |
Real estate | −1041.61 | −699.77 |
Lease and commercial service industry | −23,667.37 | −57,324.39 |
Research and development | −2159.16 | 4247.77 |
Synthesis technique services | −111,680.02 | −136,178.91 |
Water supply, environment, and public facilities management | −7460.44 | −9368.77 |
Services to households | 2.77 | −96.85 |
Education | −11,569.78 | 433.81 |
Sanitation, social insurance, and welfare | −1503.28 | 52,364.24 |
Culture, sports, and entertainment | −2316.33 | −1726.07 |
Public management and social organization | 3182.18 | 1197.50 |
Total | 788,388.46 | 556,909.01 |
Figure 2.
Water consumption by non-agricultural locally produced products and by trading.
Figure 2.
Water consumption by non-agricultural locally produced products and by trading.