Facing the challenge: barriers to sustainable water resources development in China

Transcription

1 Hydrological Sciences Journal des Sciences Hydrologiques, 44(4) August 1999 Special issue: Barriers to Sustainable Management of Water Quantity and Quality $Q-J Facing the challenge: barriers to sustainable water resources development in China CHEN JIAQI China Institute of Water Resources and Hydropower Research, PO Box 366, Beijing , China XIA JUN Wuhan University of Hydraulic and Electric Engineering, Wuhan , Hubei, China Abstract This paper addresses the water resources management problems in China. Considering the pressure of increasing population, present barriers to alleviation of floods, droughts and water environmental problems have been carefully analysed from the Chinese practical background. The discussions involve water resources and problems in managing water supply and demand in China. Due to very uneven distribution of precipitation in space and time, China frequently suffers from floods and droughts. But the coincidence of the rainy season with the warm season is favourable to crop production and thus results in high population density in the eastern part of China. In order to avert disastrous consequences of hydrological extremes floods and droughts now and in the future studying sustainable development of water resources in China is an imperative. Based on results of such studies, existing barriers to sustainable development of water resources have to be removed. A number of feasible measures adaptable to the specific conditions of China are proposed. A stepby-step strategy is suggested to keep abreast of the changes of the objective circumstances, and to provide for public consensus. Surmonter les obstacles au développement durable des ressources en eau en Chine Résumé Cet article s'intéresse aux problèmes de la gestion des ressources en eau en Chine. En tenant compte de la pression démographique, les obstacles actuels à l'atténuation des problèmes d'inondation, de sécheresse et d'environnement ont été soigneusement étudiés dans le contexte chinois. Les discussions intègrent les ressources en eau et les problèmes de gestion de l'offre et de la demande d'eau en Chine. En raison de l'extrême irrégularité des précipitations dans l'espace et dans le temps, la Chine subit fréquemment des inondations et des sécheresses. La coïncidence des précipitations et de la chaleur au sein d'une même saison est cependant favorable à la production agricole et il en résulte une densité de population importante dans l'est de la Chine. Pour prévenir les conséquences désastreuses des phénomènes hydrologiques extrêmes, crues et sécheresses d'aujourd'hui et de demain, il est impératif d'envisager un développement durable des ressources en eau de la Chine. C'est sur la base de telles études que les obstacles à un développement durables des ressources en eau devront être surmontés. Quelques mesures réalisables dans les conditions particulières de la Chine sont proposées ainsi qu'une stratégie au coup par coup permettant de rester en phase avec l'évolution des conditions objectives et d'assurer un large consensus. WATER RESOURCES IN CHINA China has a vast territory crossing different climatic and geographical zones, with a total area of 9.6 million km*, amounting to 6.4% of the total land area of the Earth Open for discussion until I February 2000

2 508 Chen Jiaqi & Xia Jun a b c d e f Liaohe Kner Basin Haihe Kiïer Basin EnanEtte River lasn Hua i he Kuer Basin Cka&ejians B. Basin ZhujianE Biwer Basin ^ \ a,i" Fig. 1 Large river basins in China. (Fig. 1). The mean annual precipitation over the whole country is 648 mm, that is 81% of the average annual precipitation over land areas of the Earth. The average annual streamflow volume in China is km 3, which makes up 5.8% of that of the Globe. The regional distribution of annual precipitation varies considerably from southeast to northwest. The northwestern part of China is subject to arid and semiarid zones, where the annual precipitation depth is lower than 400 mm. The area of arid and semiarid zones makes up 47% of the total territory of China, but the annual amount of water resources in this area is only 7% of the total volume (Table 1). Humid and semi- Tabie 1 Climatic zoning of China. Zones Arid Semiarid Total: Semi-humid Humid Utterly humid Total: Annual precipitation (mm) < ^ >1600 Annual runoff (mm) < >800 Area percent of total China (%) Annual water resources percent of total China (%)

3 Facing the challenge: barriers to sustainable water resources development in China 509 Table 2 Total annual runoff amount and unit amounts for northern and southern major river basins in China. North South A B C D A,B,C,D E F E,F River basin Liaohe Haihe-Luanhe Huanghe Huaihe Changjiang Zhujiang Ratio of northern to southern parts (%) River runoff (km 3 ) Population (x 10 6 ) Farmland (Mha) River runoff per cap. (m 3 ) River runoff per unit farmland (m 3 ha 1 ) humid zones, to which the southeastern part of China belongs, cover 53% of the area of the country. The annual amount of water resources, however, makes up 93% of the total water resources in China. The farmland area in the northern part of China is significantly higher than in the southern part, as shown in Table 2. In the four major basins in the north (of the rivers Liaohe, Haihe, Huanghe or Yellow River and Huaihe), the farmland covers 40.2 million ha, accounting for 41% of the total farmland area in China, but the annual amount of river runoff is only 163 km 3 (i.e. 6% of the national total in China). The per capita runoff volume here is only 431 m 3 per year, that is far below the volume of 1000 m 3 per capita generally recognized worldwide as a water shortage criterion. The available water volume per unit farmland area is low only 4050 m 3 ha" 1, that is 14% of the national average. In the much wetter river basins of Changjiang (Yangtze River) and Zhujiang (Pearl River) in the southern part of China, the farmland area is 28.1 million ha, that is 29% of that in China. Here the annual amount of river runoff reaches 1312 km 3, accounting for 48% of that in the whole of China. Calculating average annual values per capita and per unit (ha) farmland area, one obtains 2840 m 3 and m 3 of water, respectively (Chen, 1994, 1996a,b). The coincidence of the rainy season with the warm season is favourable to crop production and as a result the population of China ranks the first among all countries in the world, amounting in 1996 to 1.25 billion. Therefore China has to feed 22% of the world population having at its disposal as little as 6.4% of the world land area, 7.2% of the world farmland and 5.8% of the world annual runoff. The population density in the southeastern part of China is very high, and the per capita farmland area is low, being of the order of 0.05 ha. The seasonal and yearly variations of precipitation and streamflow in China are comparatively large. Precipitation within four months of the flood season may make up 60-80% of the annual total. The ratio of the annual streamflow in a wet year to that in a dry year usually approaches five in the southern part, and may exceed ten in the north. Thus, disasters related to hydrological extremes floods, waterlogging and droughts occur frequently. Therefore a high awareness of hydrological extremes is of major concern and guides development and utilization of water resources in China. As an example, a time series of several consecutive flood peaks in the most recent,

4 510 Chen Jiaqi & Xia Jun ) 0) J-l to u D g water stage s Jun 11-OLn 21-Oun 01-Jul U-Oul 21-JuL 31-JuL 10-Arr 20-Ag Fig. 2 Flood hydrograph, 1 June-27 August 1998 at Yichang on the Yangtze River, China. disastrous Yangtze flood of 1998 at Yichang, 30 km downstream of the famous Three Gorges Project, is shown in Fig. 2. The rivers in China are remarkably sediment-laden. The Huanghe (Yellow River) is well known for its very high annual sediment volume of 1.6 Gt on average, which ranks this river the first among all large rivers in the world. The annual sediment load of the Changjiang (Yangtze River) is also high: nearly 500 Mt. The sediment transport problem brings about the difficulties in water resources development work. PROBLEMS IN MANAGING WATER SUPPLY AND DEMAND IN CHINA Water demand and use keep growing with socio-economic development. By the end of 1993 the total water use reached 520 km 3 year" 1, with agricultural use (irrigation, forestry, fishery, rural domestic, etc.) in the range of 78%, industrial use 17%, and domestic urban use 5% (Table 3). Since the 1980s, the balance between water supply and demand is becoming more difficult to maintain, especially in the river basins of northern China. As shown in Table 2, the average annual volumes of per capita water availability for the Haihe-Luanhe and Huaihe basins are only 251 and 431 m 3, respectively. The population growth is the main factor responsible for the increase in water demand. Despite the strict family planning policy in China, the natural population growth rate in 1996 was still 1.04%. Firm implementation of this policy may lead to a zero natural growth rate of population in the middle of the twenty-first century, and the stable population figure in China may reach billion. In order to keep the per capita agricultural output increasing, the increase in rate of agricultural output should exceed that of population growth. Meanwhile, the industrial output value

5 Facing the challenge: barriers to sustainable water resources development in China 511 Table 3 Annual volume of water uses in China (1993). Basins of river Liaohe and other rivers in the northeast Haihe-Luanhe Huanghe Huaihe Changj iang Zhujiang Total China Total water use (km 3 ) Ratio* (%) *Ratio: water use to water resources. Water use per cap. (m 3 ) Percentage in different sectors (%) Agriculture Industry Urban domestic Rural domestic should grow at an even higher rate so that the per capita GDP in China can strive towards the values characterizing developed countries of the world. Until now China is a developing country and possesses a comparatively weak industrial base. Its per capita national income is therefore very low. In the 1990s, per capita GDP in China is less than one thirtieth of that in the developed countries. Accordingly, development of the national economy of China is an imperative, and the output of industrial production should grow considerably (Chen, 1995), thus causing a major increase in industrial water demand. With the industrial development, future urban growth is unavoidable. Consequently, urban domestic water demand, which is characterized by its higher spatial concentration and higher required supply reliability, is bound to rise. The total volume of annual water resources in China is about 2800 km, in which the surface water provides 2700 km 3, and groundwater resources in shallow aquifers (after deducting the portion feeding to streams) mainly in plain areas account for about 100 km 3. This portion of groundwater does not form surface runoff, but can be extracted for use or can be depleted by évapotranspiration from the land surface into the atmosphere. As far as the composition of streamflow is concerned, flood waters constitute a significant portion of annual river flow of China. When floods occur, the general practice is to drain the flood water into the sea as fast as possible, except for a small portion that can be stored in the existing reservoirs. Therefore, only part of the annual streamflow can be regarded as a usable water resource. Due to the significant seasonal and inter-annual variability of precipitation and streamflow in China, the ratio of usable water resources volume to the total annual volume of water resources in China is comparatively lower than that in other regions of the world. It is assessed that usable water resources are of the order of only 800 km J, or a little more, annually. At present the volume of total water uses in China is approximately 500 km 3 year" 1. In the future the population may increase by 25-30% over the census of 1996 and the national economy may expand ten times, but the total annual volume of water use in China cannot be doubled in any case. The situation will become even more severe in the next century, particularly in the river basins in northern China. Among the large rivers in China, streamflow in the lower reaches of Haihe River has dropped significantly and even streamflow dry-up

6 512 Chen Jiaqi & Xia Jun was observed, due to competition in water use since the 1970s. As a result, the large important city, Tianjin an industrial, commercial and transportation centre in northern China, which is located near the mouth of the Haihe River has been facing water scarcity since the 1970s. In order to reduce the problem for Tianjin, an interbasin water transfer engineering project for conveying water from the Luanhe River to Tianjin was implemented at the beginning of the 1980s. Similar pressure has been observed in the Huanghe (Yellow River), the second largest river in China, whose basin had been the cradle of the Chinese nation and the place of origin of the ancient Chinese culture. The River Huanghe has a basin area of km 2, with a natural annual runoff volume of 59.2 km 3. Since the 1970s numerous streamflow dry-up episodes have been observed in the lower reaches of the Huanghe River, while streamflow dry-up has occurred almost every year in the spring season since the late 1980s. In 1997, the no-streamflow episodes in the lower reaches of the Huanghe River lasted more than 200 days. The process of streamflow dry-up in the lower reaches of the Huanghe River attracted great attention in all sectors of society and triggered broad discussions of the possible causes for such phenomena. The main reason seems to be a strong increase in water use in the basin, and poor management of water withdrawals along both banks of the river. In this period, the natural streamflow from the upper and middle reaches of the Huanghe River was only slightly lower than normal. As the Huanghe is a sediment abundant river, the sedimentation process in the downstream river course became more serious owing to the decrease of streamflow, and thus the flow conveyance and flood routing capacity were significantly reduced. This has further aggravated the threat from flood disasters. Furthermore, due to the increase in water use, vast volumes of groundwater were pumped out resulting in a major decrease of the groundwater table. The increase in water use also brings about a deterioration of the quality of water, further emphasizing the tense relationship between water supply and demand. The main challenges for China in the twenty-first century will be related to water problems, involving balancing of the water supply-demand relationship with socio-economic development, and the protection of water quality and the environment. QUO VAMMUS? Since the World Commission on Environment and Development (WCED) put forward the idea of sustainable development with its authoritative explanation in 1987, a way out seems to be sought from the awkward predicament of the contradiction between development and environment (WCED, 1987). Many papers seeking the way to implement this idea in the field of water resources have been presented with interesting and valuable views in order to further explain or extend the idea (Biswas, 1991 ; Haimes, 1992; Plate, 1993; Falkenmark, 1997; Loucks, 1997; Kundzewlcz, 1997; Slmonovic, 1996; Takeuchi et ai, 1998). To cope with water resources problems, China should advance, as early as possible, along the road of sustainable development, including the sustainable development and utilization of water resources. In 1988 the China Water Law was promulgated, in which a principle of integrated water management was established. The integrated management is introduced in the Water Law for reconnaissance, planning, development, utilization and protection of the water resources.

7 Facing the challenge: barriers to sustainable water resources development in China 513 Nevertheless, in practice, some barriers are being met during implementation of the Water Law. Apparently the current administrative system of governmental departments and institutions, as well as their division of functions and responsibilities related to water affairs, which have been formed through history, do not fit well the integrated water resources management principle. In addition, in different strata of Chinese society there is still a lack of comprehension of the principle of sustainable development, which leads to reluctance and inadequate performance. Accordingly, one should start from feasible measures for diminishing possible resistance and reluctance. Barriers and obstructions can be overcome only using a step-by-step approach aiming at sustainable water resources development. In this process it is necessary to consider carefully the real conditions of the nation and to take the most appropriate and practical measures. These considerations should involve the present level of socio-economic development, the current administrative and institutional structures, and the financial, technical and scientific reference levels of the country. In particular, the general awareness involving governors, officials, administrators, office staff and professionals of different levels and ranks, and the broad public, is of concern. Only after full consideration of the above issues, can decisions be made on what measures may be put forward. At the present stage the following ideas may be seen as feasible in China: (a) Integrated national water resources development planning based on the principle of sustainable development is the prerequisite for integrated management of water resources. This integrated planning should be formulated so that the main functions of water resources, closely related to the national economy and people's livelihoods, may be brought into play and bring about optimal benefits to the society. At the same time, it should maintain the health of ecosystems and the status of the environment, avoiding their deterioration. Once the planning is approved by a national authority, it should be confirmed in a legal form with binding force, and thereby all projects and measures related to water uses should be kept in the context of the approved planning. Certainly, the planning should be revised periodically and corrections approved by relevant authorities to cope with the changes in social and economic development in the concerned regions. Integrated planning may be considered as the first step to implementation of the principle of the integrated management of water resources. In its formulation, all departments and institutions which are interested in and concerned with water resources development, utilization and protection may take part and put forward their proposals and recommendations. Therefore, the integrated planning work seems to be easier to execute than other functions of integrated management. (b) A revised water resources assessment activity is fundamental for comprehensive planning of water resources. In response to the Mar del Plata Action Plan issued in 1977, WMO and UNESCO published a handbook to assist countries to evaluate their water resources assessment activities (WMO & UNESCO, 1988). However, the authors of this handbook explained that it dealt only with the basic water resources assessment, involving the collection and processing of existing hydrological and hydrogeological data and auxiliary data, i.e. without touching upon the development and utilization of water resources. It would be useful to extend the assessment content to meet the requirements of planning. These important issues could be addressed as the natural regimes of the freshwater resources in terms of

8 514 Chen Jiaqi & Xia Jun precipitation, streamflow and shallow groundwater, water uses, the degree of water resources development, the water supply-demand situation, water-caused disasters (such as floods, waterlogging, droughts, soil salinization, and water-borne diseases), the drainage of used water, water pollution, environment. Both status quo said predictions of the foregoing aspects should be included in the assessment activity. To ensure the realization progressively, some key points on water resources formulation, utilization and management in developing processes should be studied. Among topics of particular importance for China (see Chen, 1995, 1996a,b; Xia, 1997) are: (i) Hydrological basis of water resources planning and management (e.g. understanding and description of extreme hydrological events, relationship between hydrological cycle and climate change; temporal and spatial variability of hydrological processes influenced by human activity; rules of ecosystem evolvement associated with the water cycle and water utilization, such as the process of degeneration of ecological systems due to water shortage, water excess and sedimentation, water resources assessment in a changing environment, etc.). (ii) Evaluation of the quantitative relationship between water resources development and the development of the macro-economy and society, and determination of the carrying capacity of water resources for sensitive regions in China. This involves the impact of water resources development and utilization on the hydrological cycle, and the impact of water resources development on ecosystems. Further, it involves social and macro-economic laws governing the process of water resources development under the current and future Chinese conditions, and commensurate measures for sustainability. (iii) Clear and highly efficient model for water utilization. This includes water demand rales in the water resources utilization process, the deterioration of water quality in the water use process, the increase and the limit of water demands, and so on. (iv) The optimal allocation of water resources in concert with the local economic progress and improvement of the environment. (c) Legislation related to water is of great importance to guide the behaviour of the public and water-related institutions and enterprises. The integrated management principle cannot be implemented without an appropriate legislative framework. In any case, in order to realize thoroughly such principles it seems necessary to adjust and co-ordinate functions among different departments and institutions. (d) To realize the principle of sustainable development of water resources, further research into some key issues is necessary. For instance, due to the impossibility to substitute water in maintaining the survival of the environment on which people rely for existence, it is important to protect freshwater sources that may be renewed and replenished by precipitation. Therefore, in the case of off-stream water withdrawals, attention should be paid to keep the withdrawals below a reasonable limit, and the upper limit as to the sustaining capacity of water resources for a particular region should be studied early. On the basis of these studies, an optimal water resources allocation principle should be worked out, maximizing social, economic and environmental benefits, and providing the best trade-off between the

9 Facing the challenge: barriers to sustainable water resources development in China 515 present and future generations. Considering the uncertainty in the future development, it is not appropriate to use the potential of a river entirely, but rather to leave some reserve for further utilization. For all aspects of water use, the concomitant increase in waste and water pollution due to increase of water supply should be considered. As far as instream water use is concerned, the water quantity downstream does not seem to be affected, yet regulation of streamflow for the purpose of water uses may significantly alter the original natural hydrological regime and, therefore, appropriate measures should be considered as well. (e) Water engineering projects have a definite life-span of service. For example, a dam or other structure will become old and gradually lose its functionality in the sense of deteriorating resistance to load, diminishing runoff regulating capacity due to sedimentation in the reservoir and its ability to satisfy the requirements. In view of sustainable development and utilization of water resources one should think over the compensation measures so that the functions of the water-engineering project can be preserved. (f) The purpose of water resources development and utilization is to provide for the survival of the environment and for human existence. Due to imperfect understanding, some adverse environmental effects could occur in the course of development and utilization of water resources. Therefore compensatory measures should be adopted to minimize such side effects. It is necessary to inspect and summarize the issues that have occurred in practice and to seek ways of modifying the principle and methodology in the planning, design and operation of water engineering projects so that the principle of sustainable development can be put into effect. CONCLUDING REMARKS Water resources development is controlled by human behaviour in adaptation, utilization, transformation, development and protection of the water environment (Qian, 1992). But until now people are still in a process of learning about the objective world, including all aspects of natural water resources and their laws of variability. One should be very careful when dealing with the sensitive and difficult problems of water resources development and utilization. The aim is to look for a way of sustainable development of human society and the sustainable utilization of water resources that plays an important role in supporting it. The Nation should spare no efforts in the implementation of the principle of sustainable development and should be prepared to undertake correcting actions against mistakes that have been made and have resulted in violation of the objective laws ruling the water resources. REFERENCES Biswas, A. K. (1991) Water for sustainable development in the 21st century. President's address to the 7th World Congress on Water Resources, Morocco. Wat. Int. 16(4), Chen Jiaqi (1994) Water resources in China. In: Water Resources Development in China (ed. by Qian Zhengying), China Water and Power Press, Beijing. Chen Jiaqi (1995) Prospect to the water resources issues in 21st century and the coping policy. CCAST-WL Workshop Series (in Chinese), vol. 49, 1-7.

10 516 Chen Jiaqi & Xia Jun Chen Jiaqi (1996a) Global change and sustainable development of water resources (in Chinese). Adv. Wat. Sci. 7(3), Chen Jiaqi (1996b) The General Introduction of Water Resources Science. China Water and Hydropower Press, Beijing (in Chinese). Falkenmark, M. (1997) Society's interaction with the water cycle: a conceptual framework for a more holistic approach. Hydrol. Sci. J. 42(4), Haimes, Y. Y. (1992) Sustainable development: a holistic approach to natural resources management. Wat. Int. 17(4), Loucks, D. P. (1997) Quantifying trends in system sustainability. Hydrol. Sci. J. 42(4), Kundzewicz, Z. W. (1997) Water resources for sustainable development. Hydrol. Sci. J. 42(4), 467^180. Plate, E. J. (1993) Sustainable development of water resources: a challenge to science and engineering. Wat. Int. 18(2), 84^93. Qian Zhengying (1992) Water resources development in China: history, status quo and prospect. Hehai Univ. Press, Nanjing (in Chinese). Simonovic, S. P. (1996) Decision support systems for sustainable management of water resources: 1. general principles. Wat. Int. 21(4), Takeuchi, K., Hamlin, M, Kundzewicz, Z. W., Rosbjerg, D. & Simonovic, S. P. (eds) (1998) Sustainable Reservoir Development and Management. 1AHS Publ. no WCED (World Commission on Environment and Development) (1987) Our Common Future (The Brundtland Report). Oxford Univ. Press, Oxford, UK. WMO & UNESCO (1988; Water Resources Assessment Activities: Handbook for National Evaluation. WMO/UNESCO, Geneva, Switzerland. Xia Jun (1997) Advances in management of sustainable water resources system (in Chinese). Adv. Wat. Sci. 8(4), Xia Jun & HuBaoqing(1997) Water-related environmental problems and sustainability of water resources: a case study of the San Hua region, China. In: Sustainability of Water Resources under Increasing Uncertainly (ed. by D. Rosbjerg, N.-E. Boutayeb, A. Gustard, Z. W. Kundzewicz & P. F. Rasmussen) (Proc. Rabat Symp., April-May 1997), IAHS Publ. no. 240.