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Urban-Water Harmony model to evaluate the urban water management Yifan Ding, Deshan Tang, Yuhang Wei and Sun Yin
ABSTRACT Water resources in many urban areas are under enormous stress due to large-scale urban expansion and population explosion. The decision-makers are often faced with the dilemma of either maintaining high economic growth or protecting water resources and the environment. Simple criteria of water supply and drainage do not reflect the requirement of integrated urban water management. The Urban-Water Harmony (UWH) model is based on the concept of harmony and offers a more integrated approach to urban water management. This model calculates four dimensions, namely urban development, urban water services, water–society coordination, and
Yifan Ding (corresponding author) Deshan Tang Yuhang Wei Sun Yin College of Water Conservancy and Hydropower Engineering, Hohai University, 1 Xikang Road, Nanjing 210098, Jiangsu, China E-mail: [email protected]
water environment coordination. And the Analytic Hierarchy Process has been used to determine the indices weights. We applied the UWH model to Beijing, China for an 11-year assessment. Our findings show that, despite the severe stress inherent in rapid development and water shortage, the urban water relationship of Beijing is generally evolving in a positive way. The social–economic factors such as the water recycling technologies contribute a lot to this change. The UWH evaluation can provide a reasonable analysis approach to combine various urban and water indices to produce an integrated and comparable evaluation index. This, in turn, enables more effective water management in decision-making processes. Key words
| Beijing, coordination, harmony, urban development, urban–water relationship
INTRODUCTION As an essential natural resource, water is closely associated with economic development and human lives. Looking back on human history, it has long been recognized that there is a link between human welfare and water. In primitive times, human settlements were often located near major waterways for fishing and better crop irrigation. Therefore, human civilization and water are inseparably intertwined. While the water system provides necessary resources and environmental support for society, human practices, such as water drawing and drainage, pollution discharge and treatment, dam building and removal, can greatly affect water resources. Human urbanization has contributed to environment deterioration, a situation that has been worsening in recent years. The severe impairment many urban rivers face has been described as the ‘urban stream syndrome’ (Walsh et al. ). The imbalanced relationship between urban development and water has been widely discussed in recent years. These conflicts are often manifested as doi: 10.2166/wst.2014.272
water stress (Zhang et al. ), water vulnerability (Hamouda et al. ; Babel et al. ), water poverty (Sullivan ; Sullivan et al. ), water deterioration (Kleidorfer et al. ), water security (Hamdy et al. ; Yang et al. ), water scarcity (Jubeh & Mimi ), and lack of water sustainability (Peterson et al. ). In summary, the relationship between humans and water has become increasingly hostile, particularly in some developing countries. Since the industrial revolution, the urban water system has been a source of increasing stress upon the urbanization progress and has had an inverse effect on social–economic development. Therefore, there is an urgent need for more efficient and environment-friendly water utilization and management methods. Modern urban water services have expanded to include a more comprehensive assessment of water management. This requires taking into account the development of the urban systems as catchments as well as the consideration of socio-economic effects in the outline
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of water management. However, the synergistic actions of multiple stressors in these urban catchments can threaten the integrity of freshwater ecosystems. These stressors can also be confounding factors, making it difficult to accurately assess the cause of single alterations (Canobbio et al. ). Do we need to choose between urban development and water protection or could human civilization and the water system interact in harmonious equilibrium? In Western culture, the concept of ‘Harmony’ was first brought up by the Greek philosopher and mathematician, Pythagoras. In ancient China, intellectuals conceptualized harmony more in the context of sociology and philosophy. As seen in ancient teachings such as GuoYu, YiZhuan, and ZuoZhuan, the scholars viewed harmony as a desired social status. According to Lao-tzu (571BC–471BC) and Confucius (551BC–479BC), harmony is an orderly, coordinated, and natural development trajectory, which they believed to be the guiding principle for a perpetually flourishing and healthy society. They wrote that if all the elements in the society were in harmonious relationship with each other, then everything would be in coordination for better development. The value of societal harmony has remained essentially unchanged throughout Chinese history. Harmonious or not is an important criterion to judge in Chinese culture (Ding et al. ). Adopting a comprehensive method that is preconditioned on the understanding of human–nature interactions would best ameliorate the urban-water conflict. Thus, the harmony theory could offer a new window for evaluating the urban-water relationship. Based on this consideration, the Urban-Water Harmony (UWH) Model was built to evaluate urban water management and was applied to Beijing for an 11-year integrated evaluation. In this model, four dimensions, ‘urban development, urban water services, water-society coordination, and water environment coordination’, and 18 indicators were employed.
METHODS UWH model The UWH model is an interdisciplinary approach that combines social factors with the scientific method. The process involves a systematic analysis using a weighted multi-criteria assessment within a hierarchy of dimensions and data sources. The four dimensions analyzed are as follows.
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Urban development: Development is the eternal theme of humanity and the cornerstone of human society. Although
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excessive urban development beyond water carrying capacity has potential for disaster, constricting societal progress solely to make way for environmental protection is unrealistic and unsustainable. In this study, urban development dimension mainly takes social and economic development levels into consideration. Urban water services: Urban areas and their development strongly depend on the two key tasks of urban water management: supply of high-quality potable water and disposal of wastewater and stormwater. These services are central for urban residents as well as for the economic development of urban settlements (Kleidorfer et al. ). Reliable infrastructures of water supply networks, separate or combined sewer systems, and wastewater treatment plants are the basis for these urban functions. In this part, the situation of urban water supply and disposal, along with water treatment, is examined. Water–society coordination: In addition to the two developmental aspects, urban expansion in correlation with water resources needs to be emphasized. The coordination of the urban system and water elements in a harmonious relationship with each creates better development. This dimension investigates two aspects: whether water in the city can meet the urban need, and whether people use the water in an efficient and ecofriendly manner. Water–environment coordination: Without clean water, there is no future for the urban development. In our UWH model, the water–environment coordination intends to reflect the water–environment changes under human activities and urbanization. This dimension reflects the sustainable development capacity in a particular region.
UWH index system Since the dimensions themselves are too abstract to be directly measured, they were divided into basic indicators in accordance with Shao et al. (): theoretically well founded; relatively stable and independent; clear in content; measurable and comparable, easy to quantify; regionally specific; and acquirable. The UWH evaluation index system was founded according to these criteria (Table 1). Weight determination The weighing functions are critical for correct comprehensive evaluation of models. The Analytic Hierarchy Process
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Table 1
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UWH index system and weights
Indicator weight Goal (G)
Dimension (D)
Basic indicator (B)
G-D
D-B
G-B
UWH(U)
Urban development (D1)
Per capita GDP (Yuan) Annual GDP growth rate (%) Urbanization rate (%) Engel Coefficient of urban residents R&D expenditure of GDP (%) Length of tap water supply pipelines (km) Length of sewer pipes (km) Sewage treatment capacity (10,000 m3/day) Reused water of total water usage (%) Water resources per capita (m3) GDP output per unit water (Yuan/m3) Water resources supply–demand balance (%)a Sewage treatment rate (%) Proportion of eco-environmental water usage (%) Average groundwater table of the year (m) Proportion of groundwater supply (%) Compliance rate of surface water quality (%)b Compliance rate of groundwater quality (%)c
0.1891
0.3092 0.2750 0.0594 0.1168 0.2396 0.3333 0.3333 0.3333 0.2152 0.2974 0.2152 0.1503 0.1219 0.0901 0.3461 0.1999 0.1820 0.1820
0.058 0.052 0.011 0.022 0.045 0.036 0.036 0.036 0.076 0.104 0.076 0.053 0.043 0.032 0.121 0.070 0.064 0.064
Urban water services (D2)
Water–society coordination (D3)
Water–environment coordination (D4)
a
0.1091
0.3509
0.3509
The ratio of annual water resources to water demand/supply. Percentage of monitoring river sections with water quality better than class III (including class III). Class III refers to class III in the national water quality standard of China, which mainly
b
requires: dissolved oxygen 5 mg/L, chemical oxygen demand (COD) 20 mg/L, 5-day biochemical oxygen demand (BOD5) 4 mg/L, and ammonia nitrogen 1.0 mg/L. c
Percentage of monitoring wells with water quality better than class III (including class III).
(AHP) breaks down a complex problem into a multi-level hierarchic structure of objectives, criteria, sub-criteria and alternatives (Saaty ). The AHP provides a fundamental scale of relative magnitudes expressed in dominance units to represent judgments in the form of paired comparisons. A ratio scale of relative magnitudes expressed in priority units is then derived from each set of comparisons. An overall ratio scale of priorities is then synthesized to obtain a ranking of the alternatives (Saaty ). In this case study, AHP was used for capturing the perceptions of stakeholders on the relative severity of different socio-economic impacts, which will help the authorities in prioritizing their urban water management strategies (Vaidya & Kumar ). The detailed AHP procedure can be found in the works of Saaty (Saaty , 2013) The weights conducted with AHP are listed in Table 1. Indicator normalization The indicators in the indicator system can be classified into two categories. One is positive, namely, the bigger the better. The other is negative, namely, the smaller the better (Juwana et al. ). Correspondingly, the united values of the positive indicators are computed as shown in Equation (1),
and the negative indicators are computed as shown in Equation (2) xi ¼
zi zmin zmax zmin
xi ¼ 1
zi zmin zmax zmin
(1)
(2)
where: xi is the normalized value of indicator i, zi is the initial value of indicator i, and zmax and zmin are maximum and minimum values in the sample set, respectively. Computation of the UWH index Calculation of three dimensions using Equation (3) Dj ¼
X
ωij xi
(3)
where: Dj is the value of dimension j, and ωij refers to the weights expressing the relative importance of basic indicator i in dimension j. Calculation of UWH composite value using Equation (4) UWH ¼
X
ωj D j
(4)
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where: UWH is the UWH value of the study area and ωj is the weights expressing the relative importance among the dimensions, j ¼ 1, 2, 3, 4. The weights ωij and ω jk are all between 0 and 1 and add up to 1 as per Equation (5) X
ωij ¼ 1,
X
ωj ¼ 1
(5)
i
Case study Beijing city was selected as a validation area to conduct the UWH model. Data collected over 11 years, from 2001 to 2011, illustrate the urban-water relationship changes over time. Beijing (116 250 29″E, 39 540 20″N) is the capital of China and the political and cultural center of this country. Beijing covers an area of 16,410.54 km2, including an urban area of 12,187 km2, with an average altitude of 43.5 m. According to China National Bureau of Statistics, at the end of 2013, Beijing’s resident population is 21.148 million, excluding the large floating population. Beijing belongs to the temperate zone continental monsoon climate, with hot and rainy summers, cold and dry winters, and short springs and autumns. This city has an average annual rainfall of 570 mm, 80% of which is concentrated in June, July and August. Beijing is a city facing serious water scarcity; annual water resources per capita are around 150 m3, which is equal to 1/8 of China and 1/30 of the world. In the past 60 years, particularly in the most recent 30 years, with city expansion, growing population, and rapid economic and social development, Beijing has become even drier, with a grim outlook for water supply versus demand (Zhai et al. ). There are no major rivers in the city, and today the water supply for Beijing relies mainly on groundwater and from the surrounding Hebei Province. The observed values of each indicator are obtained from Beijing Statistics Yearbook (2002–2013), Beijing Water Bulletin (2002–2013), Beijing Environment Bulletin (2002– 2013), etc. Collected data are presented in Table 2, and on this basis dimensional values and UWH value were calculated. W
W
RESULTS AND DISCUSSION The application of the UWH model provides a novel approach to access the urban water management in Beijing. Our results show that in 2002 the water situation was at its
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worst, with a UWH score of 0.291 (Table 3). In contrast, the year 2008 had the best water situation with a UWH score of 0.666. As illustrated in Figure 1, the UWH value increased from 2002 until 2008, decreased in 2009 and increased again in 2010 and 2011. Generally, the urban water relationship in Beijing is evolving in a positive way. The dimensions of urban water services and water– society coordination are rising steadily (Figure 1). Although the development dimension fluctuates in some years, the water–environment coordination is evolving in a negative way. It is important to note that we used a normalization process to calculate results listed in Table 3 that represent the relative relationship instead of the absolute values. Therefore, the smaller the dimension value, the further away the dimension is from the perfect situation. For example, in the year 2001, the water service dimension score is equal to 0. However, this doesn’t mean there were no water service or facilities in 2001; rather, data from this year scored all minimums of the basic indices in this dimension relative to the 11-year comparison. The urban water services dimension, which involves water supply and drainage, and wastewater treatment in this research, increases without drawbacks. Beijing’s urban water services have experienced rapid development, which can be attributed to the continuous large-scale infrastructure construction since 2001 (Table 2). The continually improving water service industry will surely provide solid backing for urban development and promote the urban water harmony relationship. Unlike the urban service dimension, the urban development dimension of Beijing is volatile, including two low ebbs in 2002 and 2008 (Figure 1). This corresponds well to the reality: the annual GDP growth rates of Beijing in 2002 and 2008 are 10.2% and 9%, respectively, which are the lowest values calculated between 2001 to 2008 (Table 2). After 2008, the Chinese government slowed down the development pace in consideration of green economics and sustainability. The development dimension line is low and increased at a slower rate following 2008. The water–society coordination dimension mainly discusses two topics: how people use water and whether water volume can meet that need. The results of this dimension in Beijing reflect efforts the city has invested in water management. Beijing is among the thirstiest big cities around the world, owing to very limited precipitation, large population, and significant industrial production. Under these adverse circumstances, Beijing put extensive funds and efforts into water conservation. This large investment, combined with strict enforcement of laws to
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Table 2
Basic indicator values of Beijing, 2001 to 2011
Dimension
Basic indicator
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
D1
Per capita GDP (Yuan) Annual GDP growth rate (%) Urbanization rate (%) Engel Coefficient of urban residents R&D expenditure of GDP (%)
26,980 14.8 78.06 36.2 4.55
30,730 10.2 78.56 33.8 4.68
34,777 13.8 79.05 31.7 4.63
40,916 13.2 79.53 32.2 4.72
45,993 11.8 83.62 31.7 5.5
51,722 12.8 84.33 30.8 5.51
60,096 13.3 84.5 32.2 5.64
64,491 9 84.9 33.8 5.91
66,940 10.1 84.9 32.2 5.5
73,856 10.3 85 33.8 5.82
81,658 8.1 86.2 33.2 5.76
D2
Length of tap water supply pipelines (km) Length of sewer pipes (km) Sewage treatment capacity (10,000 m3/day)
8,146 5,162.5 144
8,555 6,170 181
9,278 6,649.3 215
9,981 6,790 255
9,831 6,475 324
11,899 7,523 331
13,133 8,526 353
14,118 8,881 329
14,791 9,344 356
16,144 10,172 365
16,963 11,085 369
D3
Reused water of total water usage (%) Water resources per capita (m3) GDP output per unit water (Yuan/m3) Water resources supply–demand balance (%) Sewage treatment rate (%)
0 139.7 95.31 49.32 42
0 114.7 125.08 46.53 45
6 127.8 140.33 51.40 50.1
6 145.1 175.41 61.79 53.9
8 153.1 199.60 67.19 62.4
10 140.6 229.46 64.34 73.8
14 145.3 268.82 68.42 76.2
17 198.5 297.09 97.46 78.9
18 120.3 334.22 61.52 80.3
19 120.8 400.96 65.57 81
19 134.7 451.88 74.47 81.7
D4
Proportion of eco-environmental water usage (%) Average groundwater table of the year (m) Proportion of groundwater supply (%) Compliance rate of surface water quality (%) Compliance rate of groundwater quality (%)
0.8 16.42 69.9 68.1 53
2 17.32 70 65.1 52.5
2 18.33 70 60.7 55
2 19.04 77 57.9 50
3 20.21 72 60.2 52.7
5 21.52 71 58.7 63.2
8 22.79 70 55 61
9 22.92 65 51 57
10 24.07 62 47 52
11 24.92 61 48 57
13 24.94 59 51 51 Water Science & Technology
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Table 3
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The UWH scores of Beijing, 2001 to 2011
Dimension
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
Urban development
0.275
0.189
0.398
0.419
0.585
0.685
0.750
0.620
0.633
0.709
0.673
Urban water services
0.000
0.127
0.232
0.325
0.404
0.552
0.687
0.709
0.801
0.912
1.000
Water–society coordination
0.076
0.101
0.244
0.398
0.511
0.547
0.634
0.935
0.608
0.653
0.739
Water–environment coordination
0.648
0.587
0.542
0.343
0.415
0.519
0.439
0.407
0.297
0.359
0.338
UWH value
0.306
0.291
0.377
0.375
0.480
0.564
0.593
0.666
0.525
0.589
0.614
Figure 1
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Trend charts of the UWH dimensions of Beijing, 2001 to 2011.
reduce pollution into waterways, as well as the promotion of water reuse, was successful. Among these data, the water use efficiency score was especially notable: the GDP output per m3 water was 95.31 Yuan in 2001, and it achieved the world leading level of 451.88 Yuan in 2011 (Table 1). A peak was observed in 2008 because Beijing’s water resources were quite abundant comparatively that year. In 2008, the ratio of annual water resources to water demand/supply was 97.46%, meaning that water resources and water demand were basically balanced. Meanwhile, this value did not reach 75% in any of the other years. In the water environment dimension, we focused on the water quality, eco-environmental water usage, and groundwater overdraft. Beijing’s high dependence on groundwater has caused severe environment problems, such as overexploited funnel and deep aquifer pollution. We observed a general downward trend that declined even more in 2004. These results support our other data showing that
2004 experienced the most groundwater draft and the worst groundwater quality (Table 1). For a clearer long-term analysis, we created radar charts depicting the UWH dimensions at intervals of 5 years: 2001, 2006, and 2011 (Figure 2). It is clear that, among these years, 2001 had the best water environment, but was not developed in the urban water service. In 2006, the other three dimensions improved; however, the overall water environment was worse than in 2001. This declining trend continued in 2011, where the urban-water relationship is still imbalanced.
CONCLUSIONS Based on the harmony concept, we propose the UWH model as a holistic assessment to evaluate the urbanwater relationship. The model contains an index system of 18 indicators categorized into four dimensions: urban
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Figure 2
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Radar charts of the UWH dimensions of Beijing, 2001, 2006 and 2011.
development, urban water services, water–society coordination, and water–environment coordination. The four dimensions in the UWH model have different emphases and cannot be substituted as an integrate framework. In this study, the UWH evaluation was applied to Beijing for an 11-year evaluation. The results demonstrate that Beijing’s urban-water relationship is generally evolving in a positive way, mainly due to the improved scientific use of water, although the water shortage and water environment problems are still disconcerting. However, it should be noted that the positive trend of Beijing’s water situation partly depends on the large amount of funding and strong policy support inherent in its position as the capital city. For decades, Beijing has sourced water from the surrounding Hebei Province to meet the gap in water demand. Since 2008, Beijing has received some water by Central Line Project of South-toNorth Water Diversion. The water head of this diversion project is in the Hubei Province, 1,241 km from Beijing, and the whole construction cost is more than 200 billion Yuan. This approach can be used in other cities or regions around the world, since the index weights can be adopted according to the local conditions. Since the groundwater problem in Beijing is particularly severe and has attracted much attention, the relevant indices in our AHP evaluation were more heavily weighted. When applied in other cases, the user can either set the relative importance of the AHP progress, or just apply it as is. The UWH model combines both the human and natural language to assess the urban water situation in an integrated approach. This model will enable decision makers to spot the weaknesses in their city’s water development plan, so as to devise strategies and policies to build more harmonious urban-water interactions.
ACKNOWLEDGEMENTS This article was funded by Graduate Students Research and Innovation Projects of Jiangsu Province (CXLX13_248) and Program for Changjiang Scholars and Innovative Research Team in University (IRT1233).
REFERENCES Babel, M. S., Pandey, V. P., Rivas, A. A. & Wahid, S. M. Indicator-based approach for assessing the vulnerability of freshwater resources in the Bagmati river basin, Nepal. Environmental Management 48 (5), 1044–1059. Canobbio, S., Azzellino, A., Cabrini, R. & Mezzanotte, V. A multivariate approach to assess habitat integrity in urban streams using benthic macroinvertebrate metrics. Water Science and Technology 67 (12), 2832. Ding, Y., Tang, D., Dai, H. & Wei, Y. Human-water harmony index: a new approach to assess the human water relationship. Water Resources Management 28 (4), 1061–1077. Hamdy, A., Ragab, R. & Scarascia-Mugnozza, E. Coping with water scarcity: water saving and increasing water productivity. Irrigation and Drainage 52 (1), 3–20. Hamouda, M. A., Nour El-Din, M. M. & Moursy, F. I. Vulnerability assessment of water resources systems in the Eastern Nile Basin. Water Resources Management 23 (13), 2697–2725. Jubeh, G. & Mimi, Z. Governance and climate vulnerability index. Water Resources Management 26 (14), 4147–4162. Juwana, I., Muttil, N. & Perera, B. J. Indicator-based water sustainability assessment – a review. Science of The Total Environment 438, 357–371. Kleidorfer, M., Moderl, M., Tscheikner-Gratl, F., Hammerer, M., Kinzel, H. & Rauch, W. Integrated planning of rehabilitation strategies for sewers. Water Science and Technology 68 (1), 176–183. Peterson, H. M., Nieber, J. L., Kanivetsky, R. & Shmagin, B. Water resources sustainability indicator: application of the
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watershed characteristics approach. Water Resources Management 27 (5), 1221–1234. Saaty, T. L. How to make a decision: the analytic hierarchy process. European Journal of Operational Research 48 (1), 9–26. Saaty, T. L. Decision making with the analytic hierarchy process. International Journal of Services Sciences 1 (1), 83–98. Shao, D., Yang, F., Xiao, C. & Tan, X. Evaluation of water security: an integrated approach applied in Wuhan urban agglomeration, China. Water Science and Technology 66 (1), 79–87. Sullivan, C. The potential for calculating a meaningful water poverty index. Water International 26 (4), 471–480. Sullivan, C., Meigh, J. & Lawrence, P. Application of the water poverty index at different scales: a cautionary tale. Water International 31 (3), 412–426.
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Vaidya, O. S. & Kumar, S. Analytic hierarchy process: an overview of applications. European Journal of Operational Research 169 (1), 1–29. Yang, F., Shao, D., Xiao, C. & Tan, X. Assessment of urban water security based on catastrophe theory. Water Science and Technology 66 (3), 487–493. Walsh, C. J., Roy, A. H., Feminella, J. W., Cottingham, P. D., Groffman, P. M. & Morgan, R. P. The urban stream syndrome: current knowledge and the search for a cure. Journal of the North American Benthological Society 24 (3), 706–723. Zhai, Y., Wang, J., Teng, Y. & Zuo, R. Water demand forecasting of Beijing using the time series forecasting method. Journal of Geographical Sciences 22 (5), 919–932. Zhang, R., Duan, Z., Tan, M. & Chen, X. The assessment of water stress with the water poverty index in the Shiyang river basin in China. Environmental Earth Sciences 67 (7), 2155–2160.
First received 28 February 2014; accepted in revised form 29 May 2014. Available online 13 June 2014
© IWA Publishing 2014 Water Science & Technology
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Urban-Water Harmony model to evaluate the urban water management Yifan Ding, Deshan Tang, Yuhang Wei and Sun Yin
ABSTRACT Water resources in many urban areas are under enormous stress due to large-scale urban expansion and population explosion. The decision-makers are often faced with the dilemma of either maintaining high economic growth or protecting water resources and the environment. Simple criteria of water supply and drainage do not reflect the requirement of integrated urban water management. The Urban-Water Harmony (UWH) model is based on the concept of harmony and offers a more integrated approach to urban water management. This model calculates four dimensions, namely urban development, urban water services, water–society coordination, and
Yifan Ding (corresponding author) Deshan Tang Yuhang Wei Sun Yin College of Water Conservancy and Hydropower Engineering, Hohai University, 1 Xikang Road, Nanjing 210098, Jiangsu, China E-mail: [email protected]
water environment coordination. And the Analytic Hierarchy Process has been used to determine the indices weights. We applied the UWH model to Beijing, China for an 11-year assessment. Our findings show that, despite the severe stress inherent in rapid development and water shortage, the urban water relationship of Beijing is generally evolving in a positive way. The social–economic factors such as the water recycling technologies contribute a lot to this change. The UWH evaluation can provide a reasonable analysis approach to combine various urban and water indices to produce an integrated and comparable evaluation index. This, in turn, enables more effective water management in decision-making processes. Key words
| Beijing, coordination, harmony, urban development, urban–water relationship
INTRODUCTION As an essential natural resource, water is closely associated with economic development and human lives. Looking back on human history, it has long been recognized that there is a link between human welfare and water. In primitive times, human settlements were often located near major waterways for fishing and better crop irrigation. Therefore, human civilization and water are inseparably intertwined. While the water system provides necessary resources and environmental support for society, human practices, such as water drawing and drainage, pollution discharge and treatment, dam building and removal, can greatly affect water resources. Human urbanization has contributed to environment deterioration, a situation that has been worsening in recent years. The severe impairment many urban rivers face has been described as the ‘urban stream syndrome’ (Walsh et al. ). The imbalanced relationship between urban development and water has been widely discussed in recent years. These conflicts are often manifested as doi: 10.2166/wst.2014.272
water stress (Zhang et al. ), water vulnerability (Hamouda et al. ; Babel et al. ), water poverty (Sullivan ; Sullivan et al. ), water deterioration (Kleidorfer et al. ), water security (Hamdy et al. ; Yang et al. ), water scarcity (Jubeh & Mimi ), and lack of water sustainability (Peterson et al. ). In summary, the relationship between humans and water has become increasingly hostile, particularly in some developing countries. Since the industrial revolution, the urban water system has been a source of increasing stress upon the urbanization progress and has had an inverse effect on social–economic development. Therefore, there is an urgent need for more efficient and environment-friendly water utilization and management methods. Modern urban water services have expanded to include a more comprehensive assessment of water management. This requires taking into account the development of the urban systems as catchments as well as the consideration of socio-economic effects in the outline
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of water management. However, the synergistic actions of multiple stressors in these urban catchments can threaten the integrity of freshwater ecosystems. These stressors can also be confounding factors, making it difficult to accurately assess the cause of single alterations (Canobbio et al. ). Do we need to choose between urban development and water protection or could human civilization and the water system interact in harmonious equilibrium? In Western culture, the concept of ‘Harmony’ was first brought up by the Greek philosopher and mathematician, Pythagoras. In ancient China, intellectuals conceptualized harmony more in the context of sociology and philosophy. As seen in ancient teachings such as GuoYu, YiZhuan, and ZuoZhuan, the scholars viewed harmony as a desired social status. According to Lao-tzu (571BC–471BC) and Confucius (551BC–479BC), harmony is an orderly, coordinated, and natural development trajectory, which they believed to be the guiding principle for a perpetually flourishing and healthy society. They wrote that if all the elements in the society were in harmonious relationship with each other, then everything would be in coordination for better development. The value of societal harmony has remained essentially unchanged throughout Chinese history. Harmonious or not is an important criterion to judge in Chinese culture (Ding et al. ). Adopting a comprehensive method that is preconditioned on the understanding of human–nature interactions would best ameliorate the urban-water conflict. Thus, the harmony theory could offer a new window for evaluating the urban-water relationship. Based on this consideration, the Urban-Water Harmony (UWH) Model was built to evaluate urban water management and was applied to Beijing for an 11-year integrated evaluation. In this model, four dimensions, ‘urban development, urban water services, water-society coordination, and water environment coordination’, and 18 indicators were employed.
METHODS UWH model The UWH model is an interdisciplinary approach that combines social factors with the scientific method. The process involves a systematic analysis using a weighted multi-criteria assessment within a hierarchy of dimensions and data sources. The four dimensions analyzed are as follows.
•
Urban development: Development is the eternal theme of humanity and the cornerstone of human society. Although
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•
•
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excessive urban development beyond water carrying capacity has potential for disaster, constricting societal progress solely to make way for environmental protection is unrealistic and unsustainable. In this study, urban development dimension mainly takes social and economic development levels into consideration. Urban water services: Urban areas and their development strongly depend on the two key tasks of urban water management: supply of high-quality potable water and disposal of wastewater and stormwater. These services are central for urban residents as well as for the economic development of urban settlements (Kleidorfer et al. ). Reliable infrastructures of water supply networks, separate or combined sewer systems, and wastewater treatment plants are the basis for these urban functions. In this part, the situation of urban water supply and disposal, along with water treatment, is examined. Water–society coordination: In addition to the two developmental aspects, urban expansion in correlation with water resources needs to be emphasized. The coordination of the urban system and water elements in a harmonious relationship with each creates better development. This dimension investigates two aspects: whether water in the city can meet the urban need, and whether people use the water in an efficient and ecofriendly manner. Water–environment coordination: Without clean water, there is no future for the urban development. In our UWH model, the water–environment coordination intends to reflect the water–environment changes under human activities and urbanization. This dimension reflects the sustainable development capacity in a particular region.
UWH index system Since the dimensions themselves are too abstract to be directly measured, they were divided into basic indicators in accordance with Shao et al. (): theoretically well founded; relatively stable and independent; clear in content; measurable and comparable, easy to quantify; regionally specific; and acquirable. The UWH evaluation index system was founded according to these criteria (Table 1). Weight determination The weighing functions are critical for correct comprehensive evaluation of models. The Analytic Hierarchy Process
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UWH index system and weights
Indicator weight Goal (G)
Dimension (D)
Basic indicator (B)
G-D
D-B
G-B
UWH(U)
Urban development (D1)
Per capita GDP (Yuan) Annual GDP growth rate (%) Urbanization rate (%) Engel Coefficient of urban residents R&D expenditure of GDP (%) Length of tap water supply pipelines (km) Length of sewer pipes (km) Sewage treatment capacity (10,000 m3/day) Reused water of total water usage (%) Water resources per capita (m3) GDP output per unit water (Yuan/m3) Water resources supply–demand balance (%)a Sewage treatment rate (%) Proportion of eco-environmental water usage (%) Average groundwater table of the year (m) Proportion of groundwater supply (%) Compliance rate of surface water quality (%)b Compliance rate of groundwater quality (%)c
0.1891
0.3092 0.2750 0.0594 0.1168 0.2396 0.3333 0.3333 0.3333 0.2152 0.2974 0.2152 0.1503 0.1219 0.0901 0.3461 0.1999 0.1820 0.1820
0.058 0.052 0.011 0.022 0.045 0.036 0.036 0.036 0.076 0.104 0.076 0.053 0.043 0.032 0.121 0.070 0.064 0.064
Urban water services (D2)
Water–society coordination (D3)
Water–environment coordination (D4)
a
0.1091
0.3509
0.3509
The ratio of annual water resources to water demand/supply. Percentage of monitoring river sections with water quality better than class III (including class III). Class III refers to class III in the national water quality standard of China, which mainly
b
requires: dissolved oxygen 5 mg/L, chemical oxygen demand (COD) 20 mg/L, 5-day biochemical oxygen demand (BOD5) 4 mg/L, and ammonia nitrogen 1.0 mg/L. c
Percentage of monitoring wells with water quality better than class III (including class III).
(AHP) breaks down a complex problem into a multi-level hierarchic structure of objectives, criteria, sub-criteria and alternatives (Saaty ). The AHP provides a fundamental scale of relative magnitudes expressed in dominance units to represent judgments in the form of paired comparisons. A ratio scale of relative magnitudes expressed in priority units is then derived from each set of comparisons. An overall ratio scale of priorities is then synthesized to obtain a ranking of the alternatives (Saaty ). In this case study, AHP was used for capturing the perceptions of stakeholders on the relative severity of different socio-economic impacts, which will help the authorities in prioritizing their urban water management strategies (Vaidya & Kumar ). The detailed AHP procedure can be found in the works of Saaty (Saaty , 2013) The weights conducted with AHP are listed in Table 1. Indicator normalization The indicators in the indicator system can be classified into two categories. One is positive, namely, the bigger the better. The other is negative, namely, the smaller the better (Juwana et al. ). Correspondingly, the united values of the positive indicators are computed as shown in Equation (1),
and the negative indicators are computed as shown in Equation (2) xi ¼
zi zmin zmax zmin
xi ¼ 1
zi zmin zmax zmin
(1)
(2)
where: xi is the normalized value of indicator i, zi is the initial value of indicator i, and zmax and zmin are maximum and minimum values in the sample set, respectively. Computation of the UWH index Calculation of three dimensions using Equation (3) Dj ¼
X
ωij xi
(3)
where: Dj is the value of dimension j, and ωij refers to the weights expressing the relative importance of basic indicator i in dimension j. Calculation of UWH composite value using Equation (4) UWH ¼
X
ωj D j
(4)
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where: UWH is the UWH value of the study area and ωj is the weights expressing the relative importance among the dimensions, j ¼ 1, 2, 3, 4. The weights ωij and ω jk are all between 0 and 1 and add up to 1 as per Equation (5) X
ωij ¼ 1,
X
ωj ¼ 1
(5)
i
Case study Beijing city was selected as a validation area to conduct the UWH model. Data collected over 11 years, from 2001 to 2011, illustrate the urban-water relationship changes over time. Beijing (116 250 29″E, 39 540 20″N) is the capital of China and the political and cultural center of this country. Beijing covers an area of 16,410.54 km2, including an urban area of 12,187 km2, with an average altitude of 43.5 m. According to China National Bureau of Statistics, at the end of 2013, Beijing’s resident population is 21.148 million, excluding the large floating population. Beijing belongs to the temperate zone continental monsoon climate, with hot and rainy summers, cold and dry winters, and short springs and autumns. This city has an average annual rainfall of 570 mm, 80% of which is concentrated in June, July and August. Beijing is a city facing serious water scarcity; annual water resources per capita are around 150 m3, which is equal to 1/8 of China and 1/30 of the world. In the past 60 years, particularly in the most recent 30 years, with city expansion, growing population, and rapid economic and social development, Beijing has become even drier, with a grim outlook for water supply versus demand (Zhai et al. ). There are no major rivers in the city, and today the water supply for Beijing relies mainly on groundwater and from the surrounding Hebei Province. The observed values of each indicator are obtained from Beijing Statistics Yearbook (2002–2013), Beijing Water Bulletin (2002–2013), Beijing Environment Bulletin (2002– 2013), etc. Collected data are presented in Table 2, and on this basis dimensional values and UWH value were calculated. W
W
RESULTS AND DISCUSSION The application of the UWH model provides a novel approach to access the urban water management in Beijing. Our results show that in 2002 the water situation was at its
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worst, with a UWH score of 0.291 (Table 3). In contrast, the year 2008 had the best water situation with a UWH score of 0.666. As illustrated in Figure 1, the UWH value increased from 2002 until 2008, decreased in 2009 and increased again in 2010 and 2011. Generally, the urban water relationship in Beijing is evolving in a positive way. The dimensions of urban water services and water– society coordination are rising steadily (Figure 1). Although the development dimension fluctuates in some years, the water–environment coordination is evolving in a negative way. It is important to note that we used a normalization process to calculate results listed in Table 3 that represent the relative relationship instead of the absolute values. Therefore, the smaller the dimension value, the further away the dimension is from the perfect situation. For example, in the year 2001, the water service dimension score is equal to 0. However, this doesn’t mean there were no water service or facilities in 2001; rather, data from this year scored all minimums of the basic indices in this dimension relative to the 11-year comparison. The urban water services dimension, which involves water supply and drainage, and wastewater treatment in this research, increases without drawbacks. Beijing’s urban water services have experienced rapid development, which can be attributed to the continuous large-scale infrastructure construction since 2001 (Table 2). The continually improving water service industry will surely provide solid backing for urban development and promote the urban water harmony relationship. Unlike the urban service dimension, the urban development dimension of Beijing is volatile, including two low ebbs in 2002 and 2008 (Figure 1). This corresponds well to the reality: the annual GDP growth rates of Beijing in 2002 and 2008 are 10.2% and 9%, respectively, which are the lowest values calculated between 2001 to 2008 (Table 2). After 2008, the Chinese government slowed down the development pace in consideration of green economics and sustainability. The development dimension line is low and increased at a slower rate following 2008. The water–society coordination dimension mainly discusses two topics: how people use water and whether water volume can meet that need. The results of this dimension in Beijing reflect efforts the city has invested in water management. Beijing is among the thirstiest big cities around the world, owing to very limited precipitation, large population, and significant industrial production. Under these adverse circumstances, Beijing put extensive funds and efforts into water conservation. This large investment, combined with strict enforcement of laws to
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Table 2
Basic indicator values of Beijing, 2001 to 2011
Dimension
Basic indicator
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
D1
Per capita GDP (Yuan) Annual GDP growth rate (%) Urbanization rate (%) Engel Coefficient of urban residents R&D expenditure of GDP (%)
26,980 14.8 78.06 36.2 4.55
30,730 10.2 78.56 33.8 4.68
34,777 13.8 79.05 31.7 4.63
40,916 13.2 79.53 32.2 4.72
45,993 11.8 83.62 31.7 5.5
51,722 12.8 84.33 30.8 5.51
60,096 13.3 84.5 32.2 5.64
64,491 9 84.9 33.8 5.91
66,940 10.1 84.9 32.2 5.5
73,856 10.3 85 33.8 5.82
81,658 8.1 86.2 33.2 5.76
D2
Length of tap water supply pipelines (km) Length of sewer pipes (km) Sewage treatment capacity (10,000 m3/day)
8,146 5,162.5 144
8,555 6,170 181
9,278 6,649.3 215
9,981 6,790 255
9,831 6,475 324
11,899 7,523 331
13,133 8,526 353
14,118 8,881 329
14,791 9,344 356
16,144 10,172 365
16,963 11,085 369
D3
Reused water of total water usage (%) Water resources per capita (m3) GDP output per unit water (Yuan/m3) Water resources supply–demand balance (%) Sewage treatment rate (%)
0 139.7 95.31 49.32 42
0 114.7 125.08 46.53 45
6 127.8 140.33 51.40 50.1
6 145.1 175.41 61.79 53.9
8 153.1 199.60 67.19 62.4
10 140.6 229.46 64.34 73.8
14 145.3 268.82 68.42 76.2
17 198.5 297.09 97.46 78.9
18 120.3 334.22 61.52 80.3
19 120.8 400.96 65.57 81
19 134.7 451.88 74.47 81.7
D4
Proportion of eco-environmental water usage (%) Average groundwater table of the year (m) Proportion of groundwater supply (%) Compliance rate of surface water quality (%) Compliance rate of groundwater quality (%)
0.8 16.42 69.9 68.1 53
2 17.32 70 65.1 52.5
2 18.33 70 60.7 55
2 19.04 77 57.9 50
3 20.21 72 60.2 52.7
5 21.52 71 58.7 63.2
8 22.79 70 55 61
9 22.92 65 51 57
10 24.07 62 47 52
11 24.92 61 48 57
13 24.94 59 51 51 Water Science & Technology
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Table 3
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The UWH scores of Beijing, 2001 to 2011
Dimension
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
Urban development
0.275
0.189
0.398
0.419
0.585
0.685
0.750
0.620
0.633
0.709
0.673
Urban water services
0.000
0.127
0.232
0.325
0.404
0.552
0.687
0.709
0.801
0.912
1.000
Water–society coordination
0.076
0.101
0.244
0.398
0.511
0.547
0.634
0.935
0.608
0.653
0.739
Water–environment coordination
0.648
0.587
0.542
0.343
0.415
0.519
0.439
0.407
0.297
0.359
0.338
UWH value
0.306
0.291
0.377
0.375
0.480
0.564
0.593
0.666
0.525
0.589
0.614
Figure 1
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Trend charts of the UWH dimensions of Beijing, 2001 to 2011.
reduce pollution into waterways, as well as the promotion of water reuse, was successful. Among these data, the water use efficiency score was especially notable: the GDP output per m3 water was 95.31 Yuan in 2001, and it achieved the world leading level of 451.88 Yuan in 2011 (Table 1). A peak was observed in 2008 because Beijing’s water resources were quite abundant comparatively that year. In 2008, the ratio of annual water resources to water demand/supply was 97.46%, meaning that water resources and water demand were basically balanced. Meanwhile, this value did not reach 75% in any of the other years. In the water environment dimension, we focused on the water quality, eco-environmental water usage, and groundwater overdraft. Beijing’s high dependence on groundwater has caused severe environment problems, such as overexploited funnel and deep aquifer pollution. We observed a general downward trend that declined even more in 2004. These results support our other data showing that
2004 experienced the most groundwater draft and the worst groundwater quality (Table 1). For a clearer long-term analysis, we created radar charts depicting the UWH dimensions at intervals of 5 years: 2001, 2006, and 2011 (Figure 2). It is clear that, among these years, 2001 had the best water environment, but was not developed in the urban water service. In 2006, the other three dimensions improved; however, the overall water environment was worse than in 2001. This declining trend continued in 2011, where the urban-water relationship is still imbalanced.
CONCLUSIONS Based on the harmony concept, we propose the UWH model as a holistic assessment to evaluate the urbanwater relationship. The model contains an index system of 18 indicators categorized into four dimensions: urban
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Figure 2
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Radar charts of the UWH dimensions of Beijing, 2001, 2006 and 2011.
development, urban water services, water–society coordination, and water–environment coordination. The four dimensions in the UWH model have different emphases and cannot be substituted as an integrate framework. In this study, the UWH evaluation was applied to Beijing for an 11-year evaluation. The results demonstrate that Beijing’s urban-water relationship is generally evolving in a positive way, mainly due to the improved scientific use of water, although the water shortage and water environment problems are still disconcerting. However, it should be noted that the positive trend of Beijing’s water situation partly depends on the large amount of funding and strong policy support inherent in its position as the capital city. For decades, Beijing has sourced water from the surrounding Hebei Province to meet the gap in water demand. Since 2008, Beijing has received some water by Central Line Project of South-toNorth Water Diversion. The water head of this diversion project is in the Hubei Province, 1,241 km from Beijing, and the whole construction cost is more than 200 billion Yuan. This approach can be used in other cities or regions around the world, since the index weights can be adopted according to the local conditions. Since the groundwater problem in Beijing is particularly severe and has attracted much attention, the relevant indices in our AHP evaluation were more heavily weighted. When applied in other cases, the user can either set the relative importance of the AHP progress, or just apply it as is. The UWH model combines both the human and natural language to assess the urban water situation in an integrated approach. This model will enable decision makers to spot the weaknesses in their city’s water development plan, so as to devise strategies and policies to build more harmonious urban-water interactions.
ACKNOWLEDGEMENTS This article was funded by Graduate Students Research and Innovation Projects of Jiangsu Province (CXLX13_248) and Program for Changjiang Scholars and Innovative Research Team in University (IRT1233).
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First received 28 February 2014; accepted in revised form 29 May 2014. Available online 13 June 2014
