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Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy e n v i r o n m e n t a l s c i e n c e & p o l i c y 1 4 ( 2 0 1 1 ) 1 1 3 2 – 1 1 3 8 available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/envsci The environmental changes and mitigation actions in the Three Gorges Reservoir region, China a, b,1 Quanfa Zhang *, Zhiping Lou a Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, PR China b Bureau of Life Sciences and Biotechnology, Chinese Academy of Sciences, Beijing 100864, PR China a r t i c l e i n f o a b s t r a c t The Three Gorges Dam (TGD) is by far the world’s largest hydroelectric scheme. Due to its Published on line 17 August 2011 unprecedented magnitude, the TGD has been controversial ever since it was proposed in the early 20th century and building commenced in 1993. Recent problems, including geological Keywords: disasters (e.g., landslides) in the uplands and algal blooms in the aquatic environment since Three Gorges Dam the reservoir’s partial filling to 156 m in 2006, suggest that the environmental challenge has Biodiversity conservation never been greater than now. The environmental deterioration might be further intensified Water environment when the reservoir reaches its final water level of 175 m. Solving the environmental Uplands challenges will be essential for the sustainable development of the Three Gorges Reservoir Drawdown zone region (TGRR), and environmental sustainability in the TGRR is a high priority for the nation considering its critical location in the Yangtze Basin, which contributes 40% of China’s GDP. This article reviews primary environmental assessments for biodiversity conservation, the water environment, water level fluctuation zone, and the uplands after the partial filling in the reservoir region. It also discusses the success of mitigation efforts to date. Although there are successes in mitigation particularly in conservation of endangered plants and fishes, it seems likely that environmental conditions in the TGRR could only get worse in the short term. Building a partnership among the TGD stakeholders, including local residents, gov- ernments, and international communities is necessary to meet the mounting environmental challenge in the TGRR and beyond. # 2011 Elsevier Ltd. All rights reserved. a variety of small-scale experiments and technical tests for a 1. Introduction big dam in the Yangtze River. The Gezhouba Dam, built 38 km downstream of the current Three Gorges Dam (TGD) site Sun Yat-Sen first proposed that a series of large dams be built between 1970 and 1988, essentially concluded the final tests in the Yangtze River in his 1919 article ‘‘The International before commencing building the TGD. Development of China’’, and it remained an aspiration for The TGD, begun to be built in 1993 and completed in 2009, is China over the 20th century. Since the 1930s, a number of by far the world’s largest hydroelectric scheme. It is designed feasibility studies were undertaken for constructing a large to help control floods and improve navigation on the Yangtze dam in the upper reach of the Yangtze River even after the River, and perhaps more importantly increases China’s energy China’s revolutionary governmental transition in 1949. From supply for its rapid economic development. The dam is a 1958 to 1984, China built the Lushui Dam in Chibi City, about concrete gravity type with a height of 185 m and total water 3 110 km south of Wuhan City of Hubei Province, and conducted storage capacity of 39.3 billion m . Its flood control capacity is * Corresponding author. Tel.: +86 27 87510702; fax: +86 27 87510251. E-mail addresses: [email protected] (Q. Zhang), [email protected] (Z. Lou). 1 Tel.: +86 10 68597503; fax: +86 10 68597518. 1462-9011/$ – see front matter # 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.envsci.2011.07.008 Author's personal copy e n v i r o n m e n t a l s c i e n c e & p o l i c y 1 4 ( 2 0 1 1 ) 1 1 3 2 – 1 1 3 8 1133 Fig. 1 – The Location of the Three Gorges Dam, the Gezhouba Dam and the Three Gorges Reservoir Region (TGRR), China. (A) DEM and roads and (B) land use and land cover and locations for biodiversity conservation networks. 3 22.1 billion m , increasing the flood control ability from the ever since its implementation. A comprehensive environmen- present 10-year to a 100-year frequency flood. It has installed a tal impact assessment was conducted in the 1980s (RCEETG, total generating capacity of 22,400 MW (100 billion kWh), 1987), and many of the predicted environmental problems equivalent to consumption of more than 60 million tonnes have been realized recently by the partial filling of the of raw coal annually, dramatically increasing energy supply reservoir in the past 5 years (RCEETG, 1987; Shen and Xie, for China’s economic development. Meanwhile, the dam 2004; Wu et al., 2004; Liu et al., 2006a,b; Xu et al., 2006; Zhang increases water depth by more than 100 m, effectively et al., 2006). Systematic monitoring since 1997 have also improving the navigability in the 600 km section of the provided the evidence of environmental changes in the TGRR Yangtze River between Yichang and Chongqing (Fig. 1A). and downstream of the Yangtze Basin (http://www.tgenvir- The TGD will form a reservoir with a total water surface on.org/). 2 area of 1080 km in the Yangtze River between Chongqing and Solving the environmental challenges surrounding the Yichang. The region surrounding the reservoir, with a total TGD will be essential for the sustainable development of the 2 area of approximately 58,000 km , has now become known as TGRR and remains a high priority for the country as well. the Three Gorges Reservoir Region (TGRR) (Fig. 1). Due to its However, any efforts will have to rely on the determination of unprecedented magnitude, the TGD has been controversial the environmental changes in the region that are due to the Author's personal copy 1134 e n v i r o n m e n t a l s c i e n c e & p o l i c y 1 4 ( 2 0 1 1 ) 1 1 3 2 – 1 1 3 8 construction of the TGD. The challenge has never been greater more than 85% of the species’ genetic diversity has been than now, indicated by the geological disasters (e.g., land- preserved (Li et al., 2003). With the successful development of slides) in the uplands and algal blooms in the aquatic their propagation capacity including the sexual and asexual environment that have occurred since the reservoir filled to reproduction of individual plants (Lin, 1989; Xu et al., 1998), 156 m in 2006 (Hu and Cai, 2006; Liu et al., 2006a,b; Ye et al., they have been reintroduced to their natural habitat with the 2007; Fu et al., 2010), and the situation may be intensified when objective of restoring the original communities that occurred the reservoir reaches the final water level of 175 m in the next before inundation in the TGRR (Chen et al., 1994). few years. The Yangtze River is also one of the richest areas in This article categorically summarizes the current status of freshwater fish species diversity with 361 species, of which 177 the region based on environmental and ecological research, are endemic. Up to 40 fish species have been affected due to particularly those studies published in Chinese scientific interruption of their migratory paths and the loss of spawning literature. It presents the changes in biodiversity and grounds by the construction of the Gezhouba Dam (38 km associated conservation efforts, and it reassesses the envi- downstream from the TGD) (Dudgeon, 2000; Fu et al., 2003). ronmental implications in the water environment, the water- Sharp declines in the populations of three endemic ancient level-fluctuation-zone, and the uplands after partial reservoir fish species namely the Chinese sturgeon (Acipenser sinensis), filling. In particular, mitigation strategies and conservation river sturgeon (Acipenser dabryanus), and Chinese paddlefish efforts are discussed. The ultimate objective is to help (Psephurus gladius) has been observed (Fu et al., 2003). Aquatic formulate strategies for the TGD management and environ- mammals, such as the Yangtze finless porpoise (Neophocaena mental sustainability in the TGRR. phocaenoides asiaeorientalis) and the Chinese river dolphin (Lipotes vexillifer), which has nee recently categorized as ‘‘functionally extinct’’, are also seriously threatened (Wang 2. Biodiversity conservation et al., 2006; Turvey et al., 2007; Zhao et al., 2008). The TGD has further affected the survival of mammals due to the increased One of the most immediate consequences of the dam building use of the river by shipping vessels, leading to physical injuries is the loss and fragmentation of habitats due to both the due to collision, and noise disturbance, as well as the changes inundation and the subsequent resettlement of the human in hydrological regime (Fu et al., 2003; Wu et al., 2004).