Effects of the Three Gorges Project
on the Environment of Poyang Lake

Li, Dayong; Lai, Xijun; Dong, Zengchuan; Luo, Xiao

doi:10.15244/pjoes/63171

Cited by 12 publications

(6 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a response to the decreased water level, the vegetation at high elevations tended to expand rapidly to the central part of the lake. Moreover, the vegetation replacement process has also been accelerated, especially after the operation of TGD, which is consistent with the findings of another study ( Hu et al, 2015 ) and parallel to what happened in another lake in the middle reaches of the Yangtze River, the Poyang Lake, where one vegetation type has been completely converted to another ( Li et al, 2016 ).…”

Section: Discussionsupporting

confidence: 89%

Changes of Vegetation Distribution in the East Dongting Lake After the Operation of the Three Gorges Dam, China

Xie

Tang

et al. 2018

Front. Plant Sci.

View full text Add to dashboard Cite

Water regime is regarded as the primary factor influencing the vegetation distribution in natural wetland ecosystems. However, the effect of water regime change induced by large-scale hydraulic engineering on vegetation distribution is still unclear. In this study, multi-temporal TM/ETM+/OLI images and hydrological data from 1995 to 2015 were used to elucidate how the change in water regime influenced the vegetation distribution in the East Dongting Lake (EDTL), especially after the operation of the Three Gorges Dam (TGD) in 2003. Using unsupervised and supervised classification methods, three types of land cover were identified in the study area: Water and Mudflat, Grass, and Reed and Forest. Results showed that the total vegetation area in EDTL increased by approximately 78 km2 during 1995–2015. The areas of Reed and Forest and Grass exhibited a contrasting trend, dramatic increase in Reed and Forest but sharp decrease in Grass, particularly after the operation of TGD. The lowest distribution elevations of Grass and Reed and Forest decreased by 0.61 and 0.52 m, respectively. As a result of water level variation, submergence duration increased at 20–21 m and 28 m elevations (1–13 days), but significantly decreased at 22–27 m and 29–30 m elevations (-3 to -31 days). The submergence duration of Grass and Reed and Forest was 246 and 177 days, respectively. This study indicated that wetland vegetation pattern significantly changed after the operation of TGD, mainly as a result of changes in submergence condition. Submergence duration might be an effective indicator to predict the shift of vegetation distribution in EDTL, and which could provide scientific guidance for vegetation restoration and wetland management in this lake.

show abstract

Section: Discussionsupporting

confidence: 89%

Changes of Vegetation Distribution in the East Dongting Lake After the Operation of the Three Gorges Dam, China

Xie

Tang

et al. 2018

Front. Plant Sci.

View full text Add to dashboard Cite

show abstract

“…Such events have raised concerns regarding the effectiveness of the dam in providing seasonal flow regulation. Past studies have focused on the TGD's impacts on downstream lakes, river levels and flows (Chen et al, 2016;Jiang, Ban, Wang, & Cai, 2014;Lai, Liang, Jiang, & Huang, 2014;Li, Lai, Dong, & Luo, 2016;Mei, Dai, van Gelder, & Gao, 2015;Wang, Sheng, Gleason, & Wada, 2013;Wang, Sheng, & Wada, 2017), however, the changes in flow regimes between naturalized flows and observed flows impacted by the dam and the underlying mechanism have been largely overlooked. Consequently, an analysis that compares estimated naturalized flows against flows regulated by the TGD in the period post impoundment is important for determining whether dam operations likely reduced or exacerbated low-flow or high-flow occurrences, and how the occurrence of these flow types have changed.…”

Section: Introductionmentioning

confidence: 99%

The impact of the Three Gorges Dam on summer streamflow in the Yangtze River Basin

Hao

et al. 2019

Hydrological Processes

View full text Add to dashboard Cite

The Three Gorges Dam is the world's largest capacity hydropower station located in the Hubei province along the Yangtze River in China, which began operations in 2003. The dam also functions to store and regulate the downstream releases of water in order to provide flood control and navigational support in addition to hydropower generation. Flow regulation is particularly important for alleviating the impacts of low-and high-flow events during the summer rainy season (June, July, and August). The impact of dam operations on summer flows is the focus of this work. Naturalized flows are modelled using a canonical correlation analysis and covariates of subbasin-scale precipitation resulting in good model skill with an average correlation of 0.92. The model is then used to estimate natural flows in the period after dam operation. A comparison between modelled and gauged streamflow post 2003 is made and the impact of the dam on downstream flow is assessed. Streamflow variability is found to be strongly related to rainfall variability. An analysis of regional streamflow variability across the Yangtze River Basin showed a mode of spatially negatively correlated variability between the upper and lower basin areas. The Three Gorges Dam likely mitigated the occurrence of high-flow events at Yichang station located near the dam. However, the high flow at the remaining stations in the lower reach is not noticeably alleviated due to the diminishing influence of the dam on distant downstream flows and the impact of the lakes downstream of the dam that act to attenuate flows. Three types of flow regime changes between naturalized and observed flows were defined and used to assess the changes in the occurrence of high-and low-flow events resulting from dam operations. K E Y W O R D S canonical correlation analysis, high flow, low flow, Three Gorges Dam

show abstract

“…This had brought considerable shifts in plant composition, diversity and biomass, especially for those communities that are sensitive to hydrological variations. It has been noted that under a persistent decline in lake water level, the Phragmites australis community has significantly expanded downward and occupied the residence space of the Carex cinerascens community, while the C. cinerascens community has significantly invaded into the bottomland (Yu et al, 2011). The biomass of P. australis community has decreased over one half from 1994 to 2009, and the biomass of Carex community decreased by approximately two-thirds (Wu et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Effects of water-table depth and soil moisture on plant biomass, diversity, and distribution at a seasonally flooded wetland of Poyang Lake, China

et al. 2015

View full text Add to dashboard Cite

Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetland. Poyang Lake, the largest freshwater lake in China, has been encountering dramatic changes in hydrological conditions in last decade, which greatly influenced the wetland vegetations. To explore the relationships between hydrology and vegetation distribution, water-table depth, soil moisture, species composition, diversity and biomass were measured at a seasonally flooded wetland section at Wucheng National Nature Reserve. Three plant communities, Artemisia capillaris, Phragmites australis and Carex cinerascens communities, were examined which are zonally distributed from upland to lakeshore with decreasing elevation. Canonical correspondence analysis (CCA), spearmen correlation and logistic regression were adopted to analyze the relationships between vegetation characteristics and hydrological variables of water-table depth and soil moisture. Results show that significant hydrological gradient exist along the wetland transect. Water-table demonstrates a seasonal variation and is consistently deepest in A. capillaris community (ranging from -0.5 m above ground to +10.3 m below ground), intermediate in P. australis community (-2.6 m to +7.8 m) and shallowest in C. cinerascens community (-4.5 m to +6.1 m). Soil moisture is lowest and most variable in A. capillaris community, highest and least variable in P. australis community, and intermediate and moderate variable in C. cinerascens community. The CCA ordination indicated that variables of water-table depth and soil moisture are strongly related to community distribution, which explained 81.7% of the vegetation variations. Species diversity indices are significantly positively correlated with soil moisture and negatively correlated with moisture variability, while above-and belowground biomass are positively correlated with moisture. Above-and belowground biomass present Gaussian models along the gradient of average water-table depth in growing season, while species diversity indices show bimodal patterns. The optimal average water-table depths for above-and belowground biomass are 0.8 m and 0.5 m, respectively, and are 2.2 m and 2.4 m for species richness and Shannon-Wiener indices, respectively. Outcomes of this work improved the understandings of the relationship between hydrology and vegetation.

show abstract

Effects of the Three Gorges Project on the Environment of Poyang Lake

Cited by 12 publications

References 21 publications

Changes of Vegetation Distribution in the East Dongting Lake After the Operation of the Three Gorges Dam, China

Changes of Vegetation Distribution in the East Dongting Lake After the Operation of the Three Gorges Dam, China

The impact of the Three Gorges Dam on summer streamflow in the Yangtze River Basin

Effects of water-table depth and soil moisture on plant biomass, diversity, and distribution at a seasonally flooded wetland of Poyang Lake, China

Contact Info

Product

Resources

About