Water Resources Management in the People's Republic of China by Xuetao Sun & Robert Speed & Dajun Shen

Author:Xuetao Sun & Robert Speed & Dajun Shen [Sun, Xuetao & Speed, Robert & Shen, Dajun]
Language: eng
Format: epub
ISBN: 9781317989158
Goodreads: 18564828
Publisher: Routledge
Published: 2013-09-13T00:00:00+00:00

Obstacles to the Implementation of Environmental Flows

(1) Water requirements outside the river course. Human water use, including the exploitation of groundwater, is directly impacting the delivery of environmental flows, particularly during periods of low and extremely low flow. At present, surface water resource utilization in most river basins of China exceeds 60% (e.g. the Haihe, the Yellow River, the Huaihe and the Liaohe) (Wang & Zhang, 2008a). This situation is likely to be exacerbated in the future. For example, for the Yellow River, estimates are that the water required to maintain river health and natural functions is 23–26 billion m3, while water requirements for social and economic development will reach 40 billion m3 by 2030 (Liu & Liu, 2008). The natural runoff volume of the Yellow River, however, is only about 52 billion m3. It is quite apparent both demands cannot be satisfied (Liu & Liu, 2008). In addition, in most areas of China precipitation falls mainly between June and September, whilst crop irrigation is required in April and May. Seasonal differences between precipitation and crop water requirements (and the resultant releases to provide irrigation water) have altered natural flow patterns, and present a serious obstacle to the implementation of environmental flows. Improving environmental flows will require reductions in abstractions, which in turn will require improvements in water allocation planning and the water licence system.

(2) River pollution. Despite the provision of environmental flows to some rivers, the desired ecological objectives often cannot be achieved due to the severe pollution levels in many Chinese rivers. The combination of a shortage of water together with water quality degradation exists in all seven of China's major river basins (Wang & Zhang, 2008a). In the Huaihe, for example, despite the provision for water for environmental flow purposes, water quality remains poor. As such, those implementing environmental flows need to consider, and if possible address, both water quantity and quality issues. Clearly, it is necessary to reduce exploitation and utilization rates of water resources and, critically, take additional measures to control the discharge of pollutants into rivers.

(3) Dams, reservoirs and other WRD infrastructures. Environmental benefits can be achieved by changing the operation of dams and other water storage infrastructure without necessarily altering the water volume allocated to environmental flows. Most Chinese rivers have been subject to the construction of dams, reservoirs and flood protection infrastructure (dykes, levees etc). This has altered physical habitats, disrupted longitudinal connections downstream and lateral connectivity with wetlands and floodplain habitats, and changed natural flow patterns. For example, the Sanmenxia Reservoir on the Yellow River has altered the seasonal pattern of downstream runoff, removing much of the natural seasonal variation and resulting in a relatively even flow downstream throughout the year (Guo & Yang, 2005). At present, most WRD projects are designed to provide only minimal environmental releases, with 10% of the natural runoff regarded as the standard minimum environmental flow release, based on the Tennant method (Tennant, 1976).

Researchers have shown that there is a close relationship between the operational pattern of the Sanmenxia Reservoir and incidences of no flow in the main channel (Wei et al.

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