Effects of Reservoir Impounding on Key Ecological Factors in the Three Gorges Region

Dai, Huichao; Zheng, Tiegang; Liu, Defu

doi:10.1016/j.proenv.2010.10.004

Cited by 32 publications

(18 citation statements)

References 3 publications

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“…In Eastern Asia, many recent studies deal with physico-chemical water quality including primary production, in the newly impounded Three Gorges Reservoir (e.g. Yang et al, 2006;Yang et al, 2007;Müller et al, 2008;Tullos, 2009;Dai et al, 2010;Chen et al, 2011). Since the impoundment of Three Gorges Reservoir in 2003, substantial algae blooms have been observed, particularly during the spring dry season (Cai & Hu, 2006;Tang et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Evolution of the physico-chemical water quality in the Nam Theun 2 Reservoir and downstream rivers for the first 5 years after impoundment

et al. 2015

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-The physical (temperature, conductivity and turbidity) and chemical water quality (O 2 , pH, conductivity, nutrients, major anions and cations) characteristics have been monitored in the Nam Theun 2 system (hydroelectric reservoir and rivers downstream) for the first 5 years after impoundment. The results emphasize that the impoundment of the reservoir induced a substantial modification of the water quality in the whole aquatic system which is partially controlled by the hydrodynamics in the reservoir. During the warm seasons, the reservoir water column is thermally stratified with a warm oxic epilimnion and a colder anoxic hypolimnion. During the cold dry season or during floods, the reservoir water column over-turns which enhances oxygen penetration down to the bottom waters and contributes to a global improvement of the water quality. Downstream of the reservoir, the oxygen level was always above the minimum requirement for aquatic life due to the specific design of the water intakes at the Nakai Dam and upstream of the Power House which both favour the withdrawal of a large proportion of oxygenated epilimnic waters. Over the five years, the water quality in the reservoir itself globally improved. However, the diversion of the Nam Theun River into the Xe Bang Fai watershed via the reservoir has impacted the Xe Bang Fai River in terms of temperature, conductivity and total suspended solids.

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Section: Introductionmentioning

confidence: 99%

Evolution of the physico-chemical water quality in the Nam Theun 2 Reservoir and downstream rivers for the first 5 years after impoundment

et al. 2015

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“…However, there has been less research on eutrophication in new reservoirs. Previous studies of eutrophication on new reservoirs in China have primarily focused on the Three Gorges Reservoir (Dai et al 2010;Hu and Cai 2006;Huang et al 2009;Liu et al 2004;Zheng et al 2011). By tracking and monitoring the ecological factors and water quality parameters before and after impoundment, scholars have studied succession in the aquatic community and analyzed the causes of eutrophication and algal blooms as they originate in the tributaries.…”

Section: Introductionmentioning

confidence: 99%

Eutrophication in the newly built Laohutan Reservoir during the initial impoundment period: the role of nutrient loading

et al. 2015

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The purpose of this study was to elucidate the role of nutrient loading played in the eutrophication of newly built reservoirs. Taking the Laohutan Reservoir as an example, field monitoring and laboratory experiments were conducted before and after the reservoir impoundment. According to the results, the Laohutan Reservoir was eutrophicated 4 months after its impoundment, since nutrient loading played an important role. Riverine inputs were found to be the major source of nutrients, with the contribution of greater than 72 %. Nutrients from soil were also influential during the first 20 days. Its release was gradually weakened by the routine operations of the reservoir. The release patterns of nutrients from the four main land-use types of soil (forest, bamboo groves, paddy and construction sites) were similar, but their influence to the reservoir water quality varied dramatically. And the atmosphere was also an important source of nutrients, especially nitrogen. Meanwhile, by a comparison, the Laohutan Reservoir to an older one located nearby, the newer with relatively lower trophic levels underwent a cyanobacteria bloom, while there was none in the older. It verified that new reservoirs were more prone to eutrophication than the older, and high nutrient loading is a necessary but not sufficient condition for eutrophication. The fragility of the new reservoir's ecosystem accelerated water environment deterioration, and resulted in the eutrophication and cyanobacteria bloom during the initial impoundment period.

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“…much evidence of the detrimental effects of dams on the downstream ecosystems (e.g. Dai et al, 2010;Liu et al, 2012;Domingues et al, 2014). When the river flow is controlled by dams, very large hydrological regime shifts may occur, altering the natural estuarine hydrodynamics, compromising not only the connectivity between marine and estuarine habitats, but also the retention of estuarine species.…”

Section: Discussionmentioning

confidence: 99%

Do fish larvae have advantages over adults and other components for assessing estuarine ecological quality?

Ramos

Cabral

Elliott

2015

Ecological Indicators

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Effects of Reservoir Impounding on Key Ecological Factors in the Three Gorges Region

Cited by 32 publications

References 3 publications

Evolution of the physico-chemical water quality in the Nam Theun 2 Reservoir and downstream rivers for the first 5 years after impoundment

Evolution of the physico-chemical water quality in the Nam Theun 2 Reservoir and downstream rivers for the first 5 years after impoundment

Eutrophication in the newly built Laohutan Reservoir during the initial impoundment period: the role of nutrient loading

Do fish larvae have advantages over adults and other components for assessing estuarine ecological quality?

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