News Article | November 18, 2015
Almost one year ago, Beijing began to receive water channelled by the South-to-North Water Diversion (SNWD) project. The biggest inter-basin transfer scheme in the world, the SNWD project has the capacity to deliver 25 billion cubic metres of fresh water per year from the Yangtze River in China's south to the drier north by two routes — each of which covers a distance of more than 1,000 kilometres. The project connects four major river basins, three megacities, six provinces and hundreds of millions of water users and polluters. Its success is already in question. Reservoir and canal construction costs have reportedly reached US$80 billion, and more than 300,000 people have been displaced1. Pollution and environmental fallout, as well as high maintenance costs and water prices, make the project unsustainable both ecologically and socially. And the transfer of water does not address the underlying causes of water shortages in the north, namely pollution and inefficient agricultural, industrial and urban use — the effects of which we have been studying over the past decade. North China could be self-sufficient in water without the transfer of water from the south. But the necessary steps — among them, improving local pollution monitoring and building better irrigation infrastructure — are inadequately implemented. Increasing supply is viewed as the main solution to water scarcity because of the conflicting roles of the Chinese government as both entrepreneur and regulator. Incentives for economic growth in China still outweigh incentives for pollution control and limits on water extraction, despite ever stricter environmental laws. Many industries, such as the country's huge hydropower sector, profit from expensive solutions to boosting water supplies. China's water system needs an overhaul. Institutional reforms must divorce profit motives from regulatory functions; data and decisions must be disclosed to the public; and the influence of the hydropower sector on water-resource management needs to be restricted. The volume of water being diverted along existing routes of the SNWD project must be reduced and extensions to the project must be shelved. Better local management of resources is the only way to bring secure and sustainable water to all parts of China. China's history of grand water-engineering projects is almost as old as the nation itself, and is inextricably knit with the country's politics, development and self-image. The first dam was built in around 600 bc at Anfeng Tang in eastern China. It created a still existing reservoir 100 kilometres in circumference that could irrigate an area of 24,000 square kilometres. Ever since, most of China's water-management systems have been created and run by the state. The SNWD project transports water in two ways (see 'South-to-north water transfer'). Its eastern route has the capacity to supply up to 14.8 billion cubic metres of water per year to the provinces of Jiangsu, Anhui, Shandong and Hebei, and to the city of Tianjin. The water travels through a system of pumps, rivers, lakes, reservoirs and canals that includes the Grand Canal, which was built around 500 bc. Its central route will provide up to 9.5 billion cubic metres of water per year, including one-third of Beijing's water, from the Danjiangkou reservoir on the Han River (a tributary of the Yangtze). During the construction of this route, the water level of the reservoir was raised by 13 metres, which resulted in the resettlement of 180,000 people from Shiyan city and 160,000 from Nanyang city. A third, western, route is planned that would divert up to 20 billion cubic metres of water from three tributaries of the upper Yangtze through tunnels to the upper reaches of the Yellow River. Its path is under debate and there has been no commitment to commencing its construction nor any indication of when a decision might be made1. In our view, the scope for improving water management makes this extra route unnecessary. Without question, northern China, which includes the Hai, Huai and Yellow river basins, is short of water. The region's annual per capita water availability is only around half of the international threshold for water stress2. Water scarcity is most acute in the Hai basin, where Beijing is located. Farms and cities have increasingly drawn on groundwater such that 50% of aquifers in the North China Plain are now below sea level. This scarcity is compounded by poor water quality in up to 60% of water in the rivers of the north, which further reduces the supply of clean water for drinking and domestic use2. The problem is more a scarcity of management than of natural water3. Inefficient agricultural production consumes about 75% of the region's water and is growing rapidly. In areas where cereal crops are flood irrigated, losses can exceed 50%. In addition, the lack of storage systems along the Yellow River means that farmers must use water when it is made available — not necessarily when they need it3. The idea of water scarcity in the north is perpetuated by China's government for several reasons. It justifies taking water from the south to achieve President Xi Jinping's ambitions for a mega-economic region that encompasses Beijing, Tianjin and Hebei. And it serves the interests of those in the business of supplying water, including China's huge, state-owned water-engineering firms. But the SNWD project does not ensure a reliable supply to the north. Pollution is a pervasive risk. In response to complaints about quality from provinces receiving water, the National Development and Reform Commission ordered changes in land use across the Danjiangkou reservoir catchment area to reduce urban and agricultural run-off. Development has been prohibited in some areas, and in others communities have been resettled. The use of pesticides and fertilizers has been limited and industry is subjected to stricter pollution controls. In 2015, Danjiangkou reservoir won a national award for water quality — at the cost of the impoverishment of the hundreds of thousands of people who were forced to move. And there are other costs. Wang Mengshu, a civil engineer at Beijing Jiaotong University, has suggested that the expense of maintaining the SNWD conduits was vastly under-estimated. The price of transferred water will be too expensive for farmers, who will therefore continue to exploit groundwater4. The SNWD project also poses risks in source areas. Claims of abundant water in the Yangtze hide the fact that shortages do occur. In the past decade, there have been two severe droughts in the Yangtze basin. And periods of water scarcity are more likely in the future because of an increase in the number of withdrawals and dams, as well as the effects of urbanization and climate change. The timing of water transfers is therefore important: should extractions from the Yangtze occur at times of low flow, saline waters from its estuary could be drawn in. Nearby Shanghai's population of 24 million would then face critical water shortages until discharge levels rose again5. Governance of the SNWD project remains unresolved. Both the state-owned HydroChina Corporation and the central government's SNWD project construction committee seek to control the flow of the project's waters, even though this is a core responsibility of the Chinese Ministry of Water Resources. Corporatization of the state is reaching into the management of water, creating tension between motives and profit, uncertainty about roles and responsibilities and impediments to coordinated management of the nation's water courses. In cities, rainwater harvesting and wastewater recycling can meet much of the demand. According to Qiu Baoxing, a former vice-minister of the Chinese Ministry of Housing and Urban–Rural Development, the SNWD project could have been avoided if one-third of buildings in Beijing collected rainwater. Increased investment in treatment systems, efficient irrigation and the monitoring and enforcement of pollution levels can also improve the supply of usable water2, 6, 7. Lower-quality water could be used for urban landscaping and industry, and some water-intensive activities could be moved to the south. Such solutions require coordination with local governments, which are driven by growth and profit. When bureaucrats behave like businessmen and state-owned enterprises operate like private corporations, even strong environmental laws have little effect6. By contrast, the SNWD project is easy to administrate, politically feasible and drives growth. There are signs of change. Since 2006, environmental targets have been included in performance criteria for local leaders6. And there have been experiments in increasing disclosure to the public of data on the environmental performance of firms7. Both measures have made local governments and businesses more accountable for environmental standards. They have led to lower levels of pollution and encouraged investment in cleaner technologies and the closure of inefficient plants. But the enforcement of standards and laws varies from region to region — the economic imperative still dominates in less-developed regions — and data can be falsified6. The Chinese government's authority rests on maintaining social stability and economic growth. The government must therefore respond to challenges such as corruption, public-health issues and inequality8. Given improved living standards, greater levels of education and the proliferation of social media, high levels of pollution can no longer be ignored. Both the central and local governments in China must be seen to be controlling pollution, which can lead to secrecy and misinformation. In our experience, detailed data on the flow of water and pollution levels in major rivers can be difficult to obtain and must often be paid for. As is already done for air pollution, the central and local Chinese governments should disclose information on water to demonstrate the responsible management of resources to the public. Providing accessible information about the allocation of water rights — as well as the allocation of water itself to provinces, irrigation districts and farmers — would increase public trust in the system and improve the accountability of water managers, local government and firms6. Local environmental-protection bureaus should be given the autonomy and resources to collect and analyse monitoring data independently and to enforce pollution standards. Exporters that rely on foreign investment must increasingly comply with standards and regulations as their parent companies and consumers demand proof of environmental responsibility. Industrial water users should consider cleaner production as a path to savings, new markets and improved competitiveness9. In agriculture, losses can be reduced by lining irrigation canals with concrete. Water should be supplied only at times when irrigation is necessary3. The rotation of wheat with higher-value crops that take less water to grow, such as peanuts, will also improve the efficiency of water use10. Investment in new technologies is needed, including systems to separate urban water according to quality, recycle waste water, encourage water conservation and improve the harvesting of rainwater. This would require performance targets to be set for local managers, as well as investment in and incentives for building smaller-scale water infrastructure. Campaigns to increase public awareness of water issues should also be implemented. Constraining the influence of the hydropower sector on water-resource management will help to shift public investment towards these smaller-scale technologies. The sector is already expanding into overseas markets to compensate for reduced domestic demand in the wake of disquiet about water pollution. As its limitations become clear, the SNWD project might well mark the nadir of big-engineering solutions to China's water problems.
He H.,CAS Institute of Soil and Water Conservation |
He H.,Chinese Ministry of Water Resources |
He H.,University of Western Australia |
Veneklaas E.J.,University of Western Australia |
And 2 more authors.
Trends in Plant Science | Year: 2014
Biomineralization is widespread in the plant kingdom. The most common types of biominerals in plants are calcium oxalate crystals, calcium carbonate, and silica. Functions of biominerals may depend on their shape, size, abundance, placement, and chemical composition. In this review we highlight advances in understanding physiological and ecological significance of biomineralization in plants. We focus on the functions of biomineralization in regulating cytoplasmic free calcium levels, detoxifying aluminum and heavy metals, light gathering and scattering to optimize photosynthesis, aiding in pollen release, germination, and tube growth, the roles it plays in herbivore deterrence, biogeochemical cycling of carbon, calcium, and silicon, and sequestering atmospheric CO2. © 2013 Elsevier Ltd.
Gao L.,Chinese Ministry of Water Resources |
Gao L.,University of Chinese Academy of Sciences |
Shao M.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research
Agricultural Water Management | Year: 2012
Identifying representative locations that estimate mean soil water content (SWC) for an area of interest is one of the most important applications of the concept of temporal stability but typically requires extensive sampling on multiple occasions. This study aimed to examine the feasibility of identifying temporally stable locations by using other properties (mainly soil) that were themselves relatively temporally stable, thus reducing the cost of sampling. From July 2008 to October 2010, SWCs at four soil depths (0.1, 0.2, 0.4 and 0.6. m) were measured using a neutron probe on 20 occasions, along three transects (∼30 locations for each transect) on a hillslope of the Loess Plateau, China. Summary variables were determined at corresponding locations. The results showed good temporal patterns, with mean Spearman correlation coefficients ranging from 0.63 to 0.83 for the three transects at four soil depths. Identified representative locations for the three transects well-represented the mean SWC, with a root mean square error of less than 2% and a mean error of less than 1%. Elevation and clay content of soil were the main factors affecting the spatial and temporal distribution of soil water at the hillslope scale. However, the characteristics of temporal stability differed in part among the three transects, both in temporal persistence and in the number of representative locations. Multiple linear regression equations, determined between the mean relative difference and the measured variables based on the datasets of transects 1 and 2, did not accurately predict temporally stable locations for transect 3. The a priori selection of representative locations based solely on properties of soil and elevation was determined to be infeasible at the present time. © 2012 Elsevier B.V..
Gao L.,Chinese Ministry of Water Resources |
Gao L.,University of Chinese Academy of Sciences |
Shao M.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research
Catena | Year: 2012
Knowledge of soil water storage (SWS) within soil profiles is crucial when selecting appropriate practices for the restoration of vegetation. To study the temporal stability of SWS and identify representative locations in diverse soil layers, an analysis of temporal stability was performed using Spearman rank correlation coefficients and relative differences. From July 2008 to October 2010, the SWS of three soil layers (0-1, 1-2, and 2-3. m) were measured using a neutron probe at 91 locations on a hillslope on the Loess Plateau, China. A total of 20 SWS datasets were collected over the period of measurement. The results showed that the variability of SWS decreased over time and increased over space with the increase in soil depth. High Spearman rank correlation coefficients (p< 0.01) indicated a strong temporal stability of spatial patterns for all soil layers. Temporal stability increased with increasing soil depth. Furthermore, the closer two soil layers were within a given profile and the deeper any two adjacent soil layers were, the more similar were the temporal patterns. A significant negative correlation (p< 0.01) existed between the status of soil moisture and temporal stability, and the dependency increased with soil depth. With increasing soil depth, more locations were able to estimate the mean SWS of the area. None, however, represented the mean values for all three soil layers separately. © 2012 Elsevier B.V.
Fu Z.,Nanjing Hydraulic Research Institute |
Chen S.,Chinese Ministry of Water Resources |
Peng C.,Nanjing Hydraulic Research Institute
International Journal of Geomechanics | Year: 2014
Typical triaxial compression experiments were revisited to investigate the essential mechanical behavior of rockfill materials to be reflected in constitutive modeling, such as the nonlinear dependence of the strength and the dilation on the confining pressure and the accumulation of permanent strains during cyclic loading. The mathematical descriptions of the axial stress-strain behavior during initial loading, unloading, and reloading were formulated, respectively, which enables us to represent the hysteresis loops directly without recourse to complex concepts and parameters. The axial stress-strain model was then incorporated into the constitutive framework of generalized plasticity for the modeling of cyclic behavior of rockfill materials. This task was fulfilled by defining the elastic modulus, the plastic flow direction tensor, the loading direction tensor, and the plastic modulus for different loading conditions. In particular, the plastic flow direction tensor was derived based on a stress-dilatancy equation considering the influence of loading direction, and the representation of the plastic modulus was established in terms of the tangential modulus and the elastic modulus by using the special constitutive equations under axisymmetric stress states. The cyclic model proposed in this study has three distinct features. First, the hysteresis behavior and the accumulation of permanent strains were unified and described under the framework of generalized plasticity. Second, all the loading phases were treated as elastoplastic processes so that no purely elastic regions exist in the principal stress space. Third, the introduction of two aging functions for the consideration of the hardening effect facilitates the controlling of the magnitudes of permanent strains. There are in total 13 parameters in the model, all of which can be determined easily from (cyclic) triaxial compression experiments. To check the capabilities of the model in reproducing the monotonic and cyclic behavior, typical triaxial compression experiments were simulated with the constitutive equation. Satisfactory agreement between the experimental results and the corresponding model predictions lent sufficient creditability to the effectiveness of the proposed model, which further motivates us to extend the model for more complex stress paths and apply the model in practical engineering in the future. © 2014 American Society of Civil Engineers.
Liu N.,Chinese Ministry of Water Resources
Shuikexue Jinzhan/Advances in Water Science | Year: 2013
China is a country facing water resources shortage in general and often coexists with droughts and floods. In recent years, the frequency of extreme hydrological events has been increasing, while the attenuation of water resources in the north became evident, the situation has turned out to be severe. On account of the hydrologic regimes in China, as well as the research practices on the coordinated routine and emergency management of hydrology and water resources in aspect of utilization of stormwater, strategic reserves of water resources, and water storage spaces, the paper promoted the concept of establishment of the coordinated routine and emergency management of China's hydrology and water resources. That is, combining routine management in the normal state with emergency management in the abnormal state base on the overall annual and interannual hydrological processes, to implement water resources management in the whole process of circulation of natural water cycle, so as to realize the integration of development and utilization of water resources, and flood control and drought relief, promote the efficiency of circulation of water cycle, and enhance the level of water security.
Deng L.,Northwest Agriculture and Forestry University |
Liu G.-B.,Northwest Agriculture and Forestry University |
Liu G.-B.,Chinese Ministry of Water Resources |
Shangguan Z.-P.,Northwest Agriculture and Forestry University |
Shangguan Z.-P.,Chinese Ministry of Water Resources
Global Change Biology | Year: 2014
The establishment of either forest or grassland on degraded cropland has been proposed as an effective method for climate change mitigation because these land use types can increase soil carbon (C) stocks. This paper synthesized 135 recent publications (844 observations at 181 sites) focused on the conversion from cropland to grassland, shrubland or forest in China, better known as the 'Grain-for-Green' Program to determine which factors were driving changes to soil organic carbon (SOC). The results strongly indicate a positive impact of cropland conversion on soil C stocks. The temporal pattern for soil C stock changes in the 0-100 cm soil layer showed an initial decrease in soil C during the early stage (<5 years), and then an increase to net C gains (>5 years) coincident with vegetation restoration. The rates of soil C change were higher in the surface profile (0-20 cm) than in deeper soil (20-100 cm). Cropland converted to forest (arbor) had the additional benefit of a slower but more persistent C sequestration capacity than shrubland or grassland. Tree species played a significant role in determining the rate of change in soil C stocks (conifer < broadleaf, evergreen < deciduous forests). Restoration age was the main factor, not temperature and precipitation, affecting soil C stock change after cropland conversion with higher initial soil C stock sites having a negative effect on soil C accumulation. Soil C sequestration significantly increased with restoration age over the long-term, and therefore, the large scale of land-use change under the 'Grain-for-Green' Program will significantly increase China's C stocks. © 2014 John Wiley & Sons Ltd.
Guo Z.S.,Chinese Ministry of Water Resources
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban | Year: 2010
Taking Caragana korshinskii as test object, and by using neutron probe, a long term observation was conducted on the soil water and plant growth during the process of vegetation restoration in semi-arid loess hilly area. The results showed that after seeding on waste land, the capability of plant community in conserving soil and water was promoted with time, with the depth of roots to absorb and use soil water increased and the soil water content reduced. Then, the dried soil layer appeared, and its deepness and thickness increased with increasing plant age. Therefore, the plant use of soil water had a limit, soil water resource use limit, i.e., the soil water storage when the deepness of dried soil layer was equal to the largest depth that rain could recharge. In the C. korshinskii woodland in semi-arid loess hilly area, the soil water resource use limit in 0-290 cm layer was 249.4 mm. When the soil water storage in woodland was close or equal to the soil water resource use limit, effective measures should be taken to decrease soil evapotranspiration or increase soil water supply to ensure the sustainable water use of plant roots.
Hu J.,Chinese Ministry of Water Resources
Environmental science and pollution research international | Year: 2011
From December 2008 to November 2009, an investigation of water quality was performed in the 70-km long downstream from Gezhouba Dam in Yangtze River. Twelve sites in all were chosen. Nine parameters of water quality including the total phosphorus, the total nitrogen, chlorophyll a (Chl.a), nitrite, nitrate, ammonia, water temperature, DO, and pH were monitored almost monthly. The multivariate statistical technique (cluster analysis) and the nonparametric method (Kruskal-Wallis Test and Spearman's rank correlation) were applied to evaluate the spatiotemporal variations of water quality data sets. According to the Chinese environmental quality standards for surface water (GB3838-2002), the water quality in the river section investigated can attain to the III water standards except total nitrogen. Further analysis indicated that there were no significant spatial differences in these parameters of water quality, but the sampling date had a significant effect. The temporal variation of water quality can be related to the discharge of Gezhouba Dam and moreover be affected by the reservoir regulation. During the discharge, the discharge increased the concentration of total phosphorus and then decreased the N:P ratio, which helps to the occurrence of algae blooms. The high consternation of phosphorus and the low N:P ratio show that the water body can be in the process of eutrophication during the discharge of Gezhouba Dam. In fact, Chl.a had begun to rise in the same period.
Yang K.,Chinese Ministry of Water Resources
Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban | Year: 2011
Hydroelectric cascade exploitation, one of the major ways for exploiting water resources and developing hydropower, not only satisfies the needs of various national economic sectors, but also promotes the socio-economic sustainable development of river basin. unavoidable anthropogenic impacts on the entire basin ecosystem. Based on the process of hydroelectric cascade exploitation and the ecological characteristics of river basins, this paper reviewed the major impacts of hydroelectric cascade exploitation on dam-area ecosystems, river reservoirs micro-climate, riparian ecosystems, river aquatic ecosystems, wetlands, and river landscapes. Some prospects for future research were offered, e.g., strengthening the research of chain reactions and cumulative effects of ecological factors affected by hydroelectric cascade exploitation, intensifying the study of positive and negative ecological effects under the dam networks and their joint operations, and improving the research of successional development and stability of basin ecosystems at different temporal and spatial scales.