Jin, Junlian

Zhang, Jianyun

Zhou, T. David

English

Hydraulic Engineering Repository

Article, Published VersionZhang, Jianyun; Jin, Junlian; Zhou, T. DavidChina's water security: Problems, pathways and practicesHydrolinkVerfügbar unter/Available at: https://hdl.handle.net/20.500.11970/109568Vorgeschlagene Zitierweise/Suggested citation:Zhang, Jianyun; Jin, Junlian; Zhou, T. David (2022): China's water security: Problems,pathways and practices. In: Hydrolink 2022/2. Madrid: International Association for Hydro-Environment Engineering and Research (IAHR). S. 50-52.https://www.iahr.org/library/download-paper-file?code=wFOrlmcyQt.Standardnutzungsbedingungen/Terms of Use:Die Dokumente in HENRY stehen unter der Creative Commons Lizenz CC BY 4.0, sofern keine abweichendenNutzungsbedingungen getroffen wurden. Damit ist sowohl die kommerzielle Nutzung als auch das Teilen, dieWeiterbearbeitung und Speicherung erlaubt. Das Verwenden und das Bearbeiten stehen unter der Bedingung derNamensnennung. Im Einzelfall kann eine restriktivere Lizenz gelten; dann gelten abweichend von den obigenNutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte.Documents in HENRY are made available under the Creative Commons License CC BY 4.0, if no other license isapplicable. Under CC BY 4.0 commercial use and sharing, remixing, transforming, and building upon the materialof the work is permitted. In some cases a different, more restrictive license may apply; if applicable the terms ofthe restrictive license will be binding.50  |  #HydrolinkMagazine IAHR.orgIN DEPTH >  GLOBAL WATER SECURITY2 | 2022China’s water security:Problems, pathways and practicesBy Jianyun Zhang, Junliang Jin and T David ZhouWith a vast territory and almost one fifth of the world's population,China’s water security is not only an important issue for thecountry, but also a topic worth discussing in the context ofglobal water security. Under a monsoon climate, China receivesample vapour from both the Pacific Ocean to its east and theIndian Ocean to its southwest, which would subsequently turninto rainfall over the country. However, the vast amount ofrainfall isn’t taking place regularly over seasons year-round,nor is it evenly distributed over the territory because of variousblockages out of huge variations in land elevation and topogra-phy, which marvelled the 18th century European travellers asmuch as they do to the Chinese themselves today. Moreover,China’s booming economy and growing population are bothmaking the country increasingly thirsty for water, while bringingabout more pollution to the precious resource. Similar to manyother places in the world, the country’s plight of water securityincludes, as distilled by some researchers, too little water, toomuch water, and too dirty water. While water managers endea-vour for water security of the country, many of the problemsthey have come across, pathways they are choosing, andpractices they have taken are interesting to share and discuss.Too little water: droughts and water scarcityChina is not well endowed with water in general. The per capitawater availability of China is around 2000 m3/year, which isless than one quarter of the world’s average. Though its mon-soon climate brings plenty of rainfall, the annual precipitation,if averaged over the whole country, is around 640mm, whichis about 35% less than the global average according to theFigure 1 |  Average monthly precipitation in Chinese and European Cities. Unlike European ones, cities in China receive the majority of their rain in the rainy seasonbetween July and September, and see much higher variation over the year. Data source: climate-data.org. Interactive figure available at: https://s.yicode.org.cn/kzuwxhyGlobal Precipitation Climatology Project (GPCP). Moreover,the majority of China s precipitation takes place during itsrainy season between July and September (see Figure 1),which allows rapid rotations between droughts and floods.Apart from the temporal heterogeneity, much of the rain (~80%)falls on its southern part. While annual rainfall in the southcould reach as high as 2,000 or even 3,000 mm, the vastnorthern China could only see 20 to 30 mm of precipitation.Rapid changes taking place in the country means more dis-turbance to its water system. While China’s MeteorologicalAdministration estimates that the country is very sensitiveto global warming and expects significant impact from climatechange, the country has become the world's biggest Green-house Gas emitter and its energy portfolio is still heavilyreliant on fossil fuel. The warming climate brings noticeablechanges to water. For instance, river flows have been dwindlingin the last decades, and the decrease could be up to 70%at some gauge stations on the Haihe River 1. Meanwhile, asChina’s urbanisation keeps ramping up, more people aredependent on centralised water supply. The Second NationalWater Resources Assessment Programme of China in 2012estimated that China is in shortage of 50 billion m3 of watereven in a year of normal conditions. Of a total of 661 cities,around 400 are in shortage of water and 110 among themare in severe shortage.Water stress leads to an array of problems related to it. Adirect one is drought, the frequency and impact of which havebeen increasing since the 1990s2. Insufficient water means lesswater for the environment, which degrades ecological systemsIAHR.org #HydrolinkMagazine  |  51IN DEPTH >  GLOBAL WATER SECURITY 2 | 2022and the invaluable services they provide. In the Haihe Riverbasin where Beijing is located, it is estimated that about 18%of its annual runoff should be reserved for healthy ecosystems,but the region is consuming up to 108% of the basin’s availablewater 3. Meanwhile, limited water availability also becomesa constraint on socio-economic development. Northern Chinais home to 46% of its population and has 64% of its arableland, but has to support 45% of the country’s GDP with 19%of its water.The country’s response to droughts and water scarcity hasbeen on both the demand and the supply side. To bring waterdemand under control, in 2012, China s State Council put intoforce the Most Stringent Water Management policy, which isknown as the “Three Red Lines”. The policy package caps thequantity and efficiency of water consumption, and raises thebar for water quality. Tiered water pricing is another measurethat aims at the demand side. To incentivise water saving, wateris priced differently by purposes of consumption, and prices growas the quantity of consumption grows. On the supply side, themassive inter-basin water transfer project, the South-to-NorthWater Diversion, now has two routes in operation. By January2022, the two routes have delivered more than 50 billion m3 ofwater to northern China4. Non-traditional sources of water, suchas flood, recycled or desalinated water, are also being explored.Too much water: flooding and sea level riseFlooding is a prominent and recurring disaster in China. Despitethe overall water stress, too much water is another problemfor the country in some parts, some times. According to China’sNational Flood Defence Plans, about two thirds of the countryis under significant risk of fluvial or flash flooding, and overtwo thirds of its cities face problems of urban pluvial flooding.Seasonality of precipitation in China makes the country proneto flooding in the rainy season. 2020 saw abundant precipitationand therefore extensive flooding along the Yangtze River, HuaiRiver and in the Taihu Lake Basin. As urbanisation acceleratesin China and climate change impacts kick in, cities are becomingmore vulnerable to pluvial flooding, especially under extremeprecipitation events such as the one in Zhengzhou in July 2021.Other factors that raise the risk of flooding in coastal areas arestorm surge and sea level rise. Sea level close to China, althoughfluctuating, is on a rising trend with an annual average of 3.4mm, which is higher than the global average5.The flood defence system of China consists of both engi-neering and non-engineering measures. The water engineeringsystem in China consists of around 98,000 reservoirs, 340,000kms of river dikes, 145,000 kms of sea walls, and 98 retentionareas. The National Commanding System for Flood Control, onthe non-engineering side, is a decision support system thatcombines data collection, communication, real-time forecasting,and coordinating emergency responses.In addition, initiated in 2013, the Sponge City programmeaims at streamlining the infiltration, retention, storage, purifica-tion, reuse and discharge of rainwater in cities, so as to bettermanage urban pluvial flooding. The programme prioritises localretention of rainwater, but also engineers artificial infrastructure,such as large-scale underground storage and treatment facili-ties, for managing excessive rainwater. However, these measureshave to be informed by multi-dimensional monitoring, real-timesimulation and forecasting, and risk assessment.Too dirty water: pollutionWater pollution is another challenge for China’s water security.2018 data shows that (see Figure 2), though the country hasinvested a lot in improving surface water quality, water qualityin 5 of its 10 major river basins is still not desirable. Less thanhalf of the water bodies in the Haihe (northern China) andLiaohe (northeastern China) rivers are suitable for direct humancontact. Water quality in estuaries could be even worse. Around80% of the water in the Yangtze (east China) and Pearl (southChina) estuaries is not recommended for direct human contact.About half of the lakes in China are in eutrophic state, andalmost half (46.9%) of its shallow groundwater reserves couldnot be used for water supply even after treatment.To control water pollution, China’s present strategy incorpo-rates [1] controlling sources, which targets diffusive pollutionby reducing the use of fertilisers & pesticides, and point sourcesby regulating industrial effluence; [2] improving wastewatertreatment by centralising wastewater treatment, adoptinghigher standards and improving treatment efficiency; [3] im-proving river connectivity to replenish clean water and raiseloading capacity; [4] adopting nature based solutions throughthe rehabilitation of wetlands and other ecosystem services;and [5] reforming institutions to put river/lake managementunder the explicit responsibility of local government heads (the‘River Chiefs’).ConclusionChina’s water security is a challenging issue for the countrybecause of its unique meteorological, geological, and hydrologicalfeatures. Therefore, the country is highly susceptible to droughts,Table 1 | Pluvial flooding events in Chinese cities according to various newssources.Year CitiesJinanGuangzhou, ChongqingBeijingNingbo, Yuyao, ShanghaiShanghai, Changzhou, Zhengjiang, NanjingWuhan, Nanjing, ZhengzhouGuangzhou, Changsha, Chongqing, NanjingBeijingGuangzhou, ShenzhenGuangzhouZhengzhou2007201020122013201520162017201820192020202152  |  #HydrolinkMagazine IAHR.orgIN DEPTH >  GLOBAL WATER SECURITY2 | 2022flooding, water pollution and ecological degradation. The impactof climate change and rapid urbanisation further challengesthe country by bringing higher risks and more uncertainties.To build a water-secure future, it is necessary to combine bothengineering and non-engineering measures, the former of whichenhances the robustness of the overall system of water manage-ment, and the latter develops its capacity for better resilience.The ‘too much’, ‘too little’ and ‘too dirty’ water problems maynot be unique to China only, and therefore China’s experienceand practices could be valuable for other countries challengedby similar issues. However, this does not mean that China’sstrategies are universally applicable, nor that they are flawless.First, the approach to water security taken by China reliesheavily on massive engineering. Though nature-based solutionsJianyun ZhangDr and Prof. Zhang is a leading scientist of China in the field of hydrology and water resources. He contributed extensively to China's water resourceplanning, flood control and drought relief, and climate change adaptation through his career both as a prominent scientist and government advisor. Heis member of the Chinese Academy of Engineering and fellow of the British Royal Academy of Engineering.Junliang JinDr and Prof. Jin currently co-leads the team on climate change impacts on hydrology with NHRI/RCCC, MWR. Junliang has developed a career as a well-known expert on climate change, flood risk and water resources management. He leads or has led over 40 major research projects under important initiativesfunded by MOST, NSFC, and so forth, and has published extensively on flood risk and water resources management.T David ZhouMr Zhou studied water science, policy and management at the University of Oxford and is interested in water policies and the interface between waterscience and social institutions. He currently manages outreaches and science communication at the Yangtze Institute of Conservation and Development.References1 | Zhang, J., Wang, G., Jin, J., He, R., & Liu, C. (2020). Evolution and variation characteristics of the recorded runoff for the major rivers in China during1956-2018. Advances in Water Science, 153 161.2 | Wu, Z., Yu, L., Du, Z., Zhang, H., Fan, X., & Lei, T. (2020). Recent changes in the drought of China from 1960 to 2014. International Journal of Climatology:A Journal of the Royal Meteorological Society, 40(7), 3281 3296. https://doi.org/10.1002/joc.63973 | Yang, T., Liu, J., Chen, Q., Zhang, J., & Yang, Y. (2013). Estimation of environmental flow requirements for the river ecosystem in the Haihe River Basin, China.Water Science and Technology, 67(4), 699 707. https://doi.org/10.2166/wst.2012.5714 | State Council. (2022, January 8). More than 50 billion cubic meters of water delivered by the South-to-North Diversion Project.http://www.gov.cn/shuju/2022-01/08/content_5667224.htm5 | NMDIS. (2020). China Sea Level Bulletin 2019. National Marine Data and Information Service (NMDIS). http://www.nmdis.org.cn/hygb/zghpmgb/2019nzghpmgb/are gaining popularity and influence, there is still a need formore attention in the country on how to make best of themto build a resilient infrastructure system under growing un-certainties. Second, it is not difficult to see that China’s currentstrategies are mostly top-down and government-centric.For a resilient institutional framework, it would be better forthe country to diversify the current framework by introducingmore contributions from other institutions including the mar-ket and local communities. Third, as the most vulnerablecommunities are often hit the hardest by global warmingand natural disasters, tipping the policy scale towards theirwater security would be a necessity for the country to moulda resilient society and realise, to quote its leadership, commonprosperity.Figure 2 | 2018 water quality data of China, (a) water quality by basin, (b) water quality at major estuaries, (c) eutrophication of major lakes, and (d) shallow ground-water quality. China classes surface water quality into six classes (from good to poor, Class I, II, III, IV, V and V-). Water quality below Class III is not recommendedfor direct human contact. Groundwater quality below Class IV is not recommended for water supply even after treatment. Source: State of the Environment Bulletin of China 2018

China's water security: Problems, pathways and practices

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China's water security: Problems, pathways and practices

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