Surface methane emissions from different land use types during various water levels in three major drawdown areas of the Three Gorges Reservoir

Yang, Le; Lu, Fei; Wang, Xiaoke; Duan, Xiaonan; Song, Wenzhi; Sun, Baozhen; Chen, Shuai; Zhang, Qianqian; Hou, Peiqiang; Zheng, Feixiang; Zhang, Ye; Zhou, Xiaoping; Zhou, Yongjuan; Ouyang, Zhiyun

doi:10.1029/2011jd017362

Cited by 47 publications

(25 citation statements)

References 52 publications

(70 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Globally, there is a paucity of emission data -particularly from China and India, which are hosts to many large hydropower plants 15,16 . Although a few studies have quantified GHG emissions from reservoirs in China 17,18,[20][21][22]25 , none of them measured the releases occurring at turbines and spillways. The GHG emissions from the drawdown zones of hydropower reservoirs, which can be significant 17,18,21,27,28 , have also been largely overlooked.…”

Section: Discussionmentioning

confidence: 99%

“…Although a few studies have quantified GHG emissions from reservoirs in China 17,18,[20][21][22]25 , none of them measured the releases occurring at turbines and spillways. The GHG emissions from the drawdown zones of hydropower reservoirs, which can be significant 17,18,21,27,28 , have also been largely overlooked. The lack of a comprehensive assessment of the life cycle GHG emissions of hydropower reservoirs may result in ignored or underestimated emissions, which negatively affects the ultimate objective of the Climate Change Convention 29 .…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The urgency of assessing the greenhouse gas budgets of hydroelectric reservoirs in China

Cheng

2013

Nature Clim Change

View full text Add to dashboard Cite

NATURE CLIMATE CHANGE | VOL 3 | AUGUST 2013 | www.nature.com/natureclimatechange C hina overtook the United States and became the world's largest electricity producer and consumer in 2011. The total electricity generation reached 4,722 TW h in 2011, with thermal power and hydropower contributing to 82.5% and 14.0% of the generated electricity, respectively 1 . Meanwhile, over 90% of the thermal electricity is generated by highly polluting coal-fired generation, which had a high grid emission factor of 804 g CO 2 equivalent (CO 2 e) per kW h in 2010 2 . Coal-fired plants are not only the largest stationary source emitters of greenhouse gases (GHGs) in China, but they also bring serious air pollution problems with releases of SO 2 , NO x and fine particles. Hydropower, with more than 200 GW of total installed capacity, accounts for approximately 6% of the total energy supply and over 80% of all electricity generated from renewable sources in China. Joining the global efforts to combat climate change, China is committed to increase the share of non-fossil fuels in its total energy mix to 15% by 2020. Accordingly, the production capacity of hydropower should increase by, on average, 10 to 15 GW yr −1 to help achieve this goal. Cascades of dams are currently being built, planned or proposed on the major river valleys in southwest China, where over two-thirds of the country's hydroelectric resources are located (Fig. 1). With physical water scarcity, and spatially and temporarily uneven distribution of water resources 3 , reservoir development is also a key component of China's recent heavy investment in water infrastructures to adapt to climate change, droughts and floods, and to improve food security 4 .Although hydropower is widely claimed to be a 'clean' energy source, critics have long warned of the environmental impact of large hydroelectric projects. In particular, research over the past two decades has revealed that the decay of organic matter (OM) in reservoirs could release significant amounts of CO 2 and CH 4 , and the emissions from tropical reservoirs characterized by high levels of OM and shallow depths are much higher compared with those in boreal and temperate regions [5][6][7][8][9][10][11][12][13] . Methane is 25 times more effective at trapping heat in the atmosphere than CO 2 over a 100-year period, and is responsible for over 20% of the change in the radiative forcing of the climate system 14 . It has been estimated that large dams release approximately 104 Tg CH 4 annually, or 20% of the total emissions from natural and anthropogenic sources 15 , although current estimations on GHG emissions from global hydroelectric reservoirs bear large uncertainties 13,16 .Carbon dioxide, methane and nitrous oxide are the major GHGs that can be produced in reservoirs, but nitrous oxide emissions are The urgency of assessing the greenhouse gas budgets of hydroelectric reservoirs in China Yuanan Hu, Hefa Cheng* Already the largest generator of hydroelectricity, China is accelerating dam construction to increase ...

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

The urgency of assessing the greenhouse gas budgets of hydroelectric reservoirs in China

Cheng

2013

Nature Clim Change

View full text Add to dashboard Cite

show abstract

“…The frequency of bubble occurrence was 5% in our experiment. We considered the bubble occurrence when CH 4 concentration increased abruptly in the chamber (Yang et al, 2012a(Yang et al, , 2013. However, CO 2 concentration did not increase obviously in the chambers when bubbles were trapped in the chambers, indicating that bubbles had little contribution to CO 2 emission from the TGR surface.…”

Section: Carbon Budget At the Tgrmentioning

confidence: 99%

“…Although the water inflow is remarkably larger in the flood season than in the non-flood season, the water level in TGR is controlled at 145 m artificially during the flood season (June-August) to discharge the flood water and sediments. After the flood season (in October), the reservoir begins to store clear water to a water level of 175 m (Lu et al, 2011;Yang et al, 2012a). The water quality during the non-flood season is grade III and is grade IV during the flood season, according to the surface water environment quality standard of the People's Republic of China (Yang et al, 2012b).…”

Section: Site Descriptionmentioning

confidence: 99%

“…The Three Gorges Reservoir (TGR), which was impounded in 2003, has a length of 660 km and an area of 1084 km 2 when the water level reach 175 m. The water level fluctuates between 145-175 m throughout the year, and the water falls 80-110 m when passed through the turbines in the Three Gorges Dam (TGD), producing 8.47 × 10 10 kWh of electricity in 2010, making the TGR the largest hydroelectric producer in the world (Yang et al, 2012a). Greenhouse gas (such as CH 4 ) emission from the TGR has aroused wide debate because of the remarkable spatial-temporal variations in CH 4 emission (Chen et al, 2009Lu et al, 2011;Yang et al, 2013;Zhao et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Spatial and seasonal variability of CO2 flux at the air-water interface of the Three Gorges Reservoir

Yang¹,

Lu²,

Wang³

et al. 2013

Journal of Environmental Sciences

Self Cite

View full text Add to dashboard Cite

Diffusive carbon dioxide (CO 2 ) emissions from the water surface of the Three Gorges Reservoir, currently the largest hydroelectric reservoir in the world, were measured using floating static chambers over the course of a yearlong survey. The results showed that the average annual CO 2 flux was (163.3 ± 117.4) mg CO 2 /(m 2 ·hr) at the reservoir surface, which was larger than the CO 2 flux in most boreal and temperate reservoirs but lower than that in tropical reservoirs. Significant spatial variations in CO 2 flux were observed at four measured sites, with the largest flux measured at Wushan (221.9 mg CO 2 /(m 2 ·hr)) and the smallest flux measured at Zigui (88.6 mg CO 2 /(m 2 ·hr)); these differences were probably related to the average water velocities at different sites. Seasonal variations in CO 2 flux were also observed at four sites, starting to increase in January, continuously rising until peaking in the summer (JuneAugust) and gradually decreasing thereafter. Seasonal variations in CO 2 flux could reflect seasonal dynamics in pH, water velocity, and temperature. Since the spatial and temporal variations in CO 2 flux were significant and dependent on multiple physical, chemical, and hydrological factors, it is suggested that long-term measurements should be made on a large spatial scale to assess the climatic influence of hydropower in China, as well as the rest of the world.

show abstract

Spatial and seasonal variability of diffusive methane emissions from the Three Gorges Reservoir

Yang

Wang

et al. 2013

JGR Biogeosciences

Self Cite

View full text Add to dashboard Cite

[1] To investigate temporal and spatial variations in diffusive CH 4 emission from the surface of the Three Gorges Reservoir, CH 4 emissions were measured using the static chamber technique along the mainstream of the reservoir from January to December 2010. The overall average CH 4 flux is 7.93 mg CH 4 m À2 d À1 , which is comparable to those from other temperate reservoirs but significantly lower than those from tropical reservoirs. Seasonal variations showed that CH 4 emission reached the maximum in the summer and turned to the low levels in the other seasons; such variations reflected the seasonal dynamics of temperature, dissolved oxygen, and water velocity. Moreover, the yearly average CH 4 flux decreased from upstream to downstream before the Three Gorges Dam, but CH 4 emission from the surface of the downstream river was higher than that from the surface at Zigui, the upstream water before the Three Gorges Dam. The differences in water velocity and allochthonous input of organic matter probably caused the spatial variations in CH 4 emission. These results indicate that systematic sampling is needed to better estimate CH 4 emission through coverage of the temporal and spatial scales and to better assess the influence of CH 4 emission from the Three Gorges Reservoir on climate change in China, as well as the rest of the world.

show abstract

Surface methane emissions from different land use types during various water levels in three major drawdown areas of the Three Gorges Reservoir

Cited by 47 publications

References 52 publications

The urgency of assessing the greenhouse gas budgets of hydroelectric reservoirs in China

The urgency of assessing the greenhouse gas budgets of hydroelectric reservoirs in China

Spatial and seasonal variability of CO2 flux at the air-water interface of the Three Gorges Reservoir

Spatial and seasonal variability of diffusive methane emissions from the Three Gorges Reservoir

Contact Info

Product

Resources

About