South-North Water Transfer Project Research Articles

The potential role of virtual water in solving water scarcity and food security problems in China

Water, as a source of food security, plays an essential role in ensuring sustainable food resources for a growing population. However, water scarcity has increasingly become a constraint to economic development, particularly food production. The water-food challenge is impending because of China's increasing population and water demand. The concept of virtual water is useful to analyze this problem. In this paper, the implications and policy relevance of virtual water are expounded. Based on imported food volumes, it is calculated that an annual average of 10.52 × 109 m3 of virtual water embodied in imported wheat and maize in the period between 1990 and 2000 is equivalent to 23% of the annual average transfer water volume of the South-North Water Transfer (SNWT) project. Consequently, this 29.3 × 106 ha of virtual land is equivalent to 19% of China's arable land in 2000. Using the grain import prediction and the agricultural production conditions of China, the virtual water equivalents of China in 2010 and 2020 are evaluated, and are about 88 × 109 m3 in 2010 and 95 × 109 m3 in 2020, respectively. Importing virtual water embedded in traded food can alleviate water stress and even achieve food security. Virtual water trade may compensate for water demands for not only the past but also the future. Meanwhile, water trade can store water in its virtual water form, enabling food storage to play a potential role in solving food problems, as well as promoting sustainability of water resources in China.

Virtual versus real water transfers within China

North China faces severe water scarcity--more than 40% of the annual renewable water resources are abstracted for human use. Nevertheless, nearly 10% of the water used in agriculture is employed in producing food exported to south China. To compensate for this 'virtual water flow' and to reduce water scarcity in the north, the huge south-north Water Transfer Project is currently being implemented. This paradox--the transfer of huge volumes of water from the water-rich south to the water-poor north versus transfer of substantial volumes of food from the food-sufficient north to the food-deficit south--is receiving increased attention, but the research in this field has not yet reached further than rough estimation and qualitative description. The aim of this paper is to review and quantify the volumes of virtual water flows between the regions in China and to put them in the context of water availability per region. The analysis shows that north China annually exports about 52 billion m3 of water in virtual form to south China, which is more than the maximum proposed water transfer volume along the three routes of the Water Transfer Project from south to north.

The South-North Water Transfer Project in China

After nearly half a century of planning, the construction of the controversial south-tonorth water transfer (SNWT) project in China was officially launched just before the end of 2002. This paper looks into the decision-making process of the project in the context of the country's transition from a centrally-planned economy to a market economy, rapid economic development, and severe environmental degradation. Uncertainties concerning future water demand in individual sectors are examined with reference to the latest projection prior to the launch of the project. Adjustment of project objectives and shift of the focal issues concerned over the years are elaborated. The analysis suggests a high degree of uncertainty in future water demand. The expansion of project objectives to include ecosystem recovery in the late 1990s, however, provided a decisive argument for implementing the project as no other alternative was considered available to meet the estimated ecosystem water requirement. Consequently, remaining doubts on the need for the project and concerns on adverse environmental impacts have tended to be sidelined. With the implementation of the project, the government is caught in a dilemma of keeping water prices low to substantiate the economic needs and improving water use efficiency to honor the environmental objective of the project.

Vulnerability of water discharge of large Chinese rivers to environmental changes: an overview

In an era of rapid environmental change, China is facing increasing problems in the management of its large rivers and water resources. The disastrous 1998 Yangtze floods and the emerging water shortages in north China raised further concerns about the potential impact of environmental change on extreme hydrological events such as floods and droughts. Over the past few decades, increasing water consumption by the domestic, industrial and agricultural sectors, as well as a number of human activities such as deforestation, agricultural land expansion, wetland reclamation, construction of reservoirs and roads, water diversion, and sand/stone excavation significantly affect hydro-geomorphic processes such as water discharge and sediment flux throughout China. This paper aims to provide an overview of recent research on the water discharge changes occurring in major Chinese rivers and their vulnerability to environmental change. Most of the rivers, notably in north China, have experienced significant changes in water discharge over the last few decades, indicating that they are vulnerable to climatic variations and human activities. In contrast to north China, the rivers in south China have experienced less change, but some of the detected changes displayed similar trends to those in north China, though at a slower pace. These profound changes, in addition to the on-going projects such as the Three Gorges Dam Project and the South-North Water Transfer Project, will completely alter China’s waterscape.

China: The South–North Water Transfer Project—is it justified?

The South-North Water Transfer Project (SNWTP), if fully developed, could divert 40-50 km3/yr from the Yangtse basin to the North China plain, alleviating water scarcity for 300-325M people living in what even then will be a highly water-stressed region. Construction of the next stage, diverting up to 20 km3 at a cost of about $17,000M (including $7000M in ancillary costs), is to start in 2002/3. A recent World Bank study suggests that the project is economically attractive. This conclusion has been disputed by the World Wildlife Fund (now the Worldwide Fund for Nature). This paper concludes that little confidence can be placed in either of these analyses. It therefore seeks to throw light on how the project fits within a broader regional and agricultural development setting. The project is hugely expensive, and would at the margin tend to preserve water in low value agriculture and require the resettlement of upwards of 300,000 people. On the other hand, the pace and scale of socio-economic change in China are without precedent, and adjustment problems on the North China plain are greatly exacerbated by water scarcity. Reallocation of water from irrigation to municipal and industrial uses or to the environment is socially divisive and in some instances physically impracticable. The transfer project would greatly alleviate these difficulties. It is these arguments (which are ultimately political and pragmatic), rather than those based strictly on economic or food security concerns, that make the Government's decision to proceed with the project fully understandable.

Impact on the Yangtze (Changjiang) Estuary from its drainage basin: Sediment load and discharge

This paper focuses on the sediment transport and freshwater discharging from upper Yangtze drainage basin downstream, primarily on the basis of multiyear hydrological data collected from three major hydrological gauge stations (Yichang, Hankou and Datong). Data indicate highest sediment load in Yichang (5.6 × 108 t/a), lowest in Hankou (5.1× 108 t) and second highest in Datong (5.4 ×108 t). This fluctuations are identical with what has been observed from the annual flood season. About one thirds of the sediment load are trapped in the middle Yangtze River course, where meandering river pattern prevails; rest of them are directly transported to the river mouth area via lower Yangtze River channel, where the river is typically confined by the exposed base rock and almost none is being trapped, instead, minor being drained to the mainstream from the local tributaries. To recognize this sediment delivery and river flow media is vital, because it can highlight morphologic/topographic correlation between the upper drainage basin and the estuary and the erosion and siltation in the river mouth area, where extensive coast has been exclaimed and or being exclaimed, and new navigation channel and port is being constructed. It is particularly crucial for monitoring the impact on estuarine change after 3-Gorges dam being closed in 2009. Data also indicate an increase in freshwater discharging downstream (>7.7 × 1111 m3/a), of which ∼50% derived from the upstream and another half concentrated from the local tributaries. The result shows that this numerous freshwater has constantly flowed into the river mouth area to support the estuarine aquaculture and ecosystem, where it is confronted with huge amount of tidal prism (>10 times more than that of the annual runoff) transforming from offshore. Thus, a great concern for saltwater intrusion especially during the dry season is aroused, largely due to the intense upstream agriculture irrigation and large water transfer project, such as the well-planned South-North Water Transfer project.