Water scarcity is among the main problems faced by many countries in the 21st century. According to the Human Development Report (UNDP, 2006), there are about 1.2 billion people living in areas of physical water scarcity and 1.6 billion people encountering economic water shortage. World consumption of water has been doubled every two decades, more than twice the rate of human population growth. If the trends continue, by 2025 the demand for fresh water could rise by 56% which is more than the amount of water that is currently available (Barlow, 2010). Governments have responsibilities to provide fresh and adequate water to all populations and future generations. Therefore, effective technologies have to be introduced and developed to realise the vital need to sustain all life form. China has been struggling with water scarcity in its arid northern regions for several decades. This report will focus on the North China Plain (NCP) and assess two feasible options for addressing the water crisis in this region, which are desalination and water transfer.
China is a country located in East Asia with the world’s largest population of over 1.35 billion. Covering with a total area of approximately 9.6 million square kilometers, China’s landscapes and climate vary significantly from south to north because of its vast width. Uneven distribution of water resources and severe imbalance of rainfall always lead to two opposite consequences: flooding in the south and aridity in the north.
The total area of NCP is about 140,000 km2 with a coastline of nearly 600 km. It accounts for around 12% of annual GDP and more than 10% of the total agricultural production of China. In this area, dry seasons and wet monsoons dominated in winter and summer respectively. The precipitation of China, on averages, is around 640 mm annually (Zheng et al. 2010). However, the average precipitation per year in NCP ranges from 600 mm to 25 mm only (ibid). In addition, more than 70 per cent of the precipitation occurs during the rainy season of summer (ibid). Groundwater accounts for more than 70% of the total water supply of this area to support agricultural irrigation, industrial usage, and a population of around 130 million (Liu et al. 2001). While China’s economy experienced rapid development to be the second largest one in the world, water stress of NCP also exacerbated, as it is one of the most economically active regions of China. With the continuous population growth, the amount of water resource per capita has been less than 500 cubic meters per year, which reaches the level of severe water scarcity (Liu et al. 2008). Being one of the most severe arid regions of the world, the ever-growing demands in this area could not be satisfied by the traditional water supply.
3.0 Requirements for desalination and water transfer
Desalination is a method of producing fresh water by removing salts from seawater or brackish water. This report will focus on evaluating the feasibility of RO (reverse osmosis) process, because it is the most economical and populous desalination technology, which accounts for the largest installed desalting capacity in the world (Zhou & Tol, 2003).
South-to-North Water Transfer Project (SNWT) is a scheme to divert water from upper, middle, and lower reaches of Yangtze River to the north and northwest of China from 2002 to 2050. SNWT contains three alignments: the western, middle, and eastern routes, among which the Middle Route Project and Eastern Route Project are impacting or will impact the NCP region (Zheng et al, 2010)（Figure 1).
Figure 1: The map of the South-North Water Transfer Project
Source: Zheng et al (2010).
3.1 Costs of desalination and water transfer
Cost of desalination
RO is a process of ionic filtration that separating salts from water with electrical energy (Campos, 2010). The