scholarly journals Tempo-spatial variations of zooplankton communities in relation to environmental factors and the ecological implications: A case study in the hinterland of the Three Gorges Reservoir area, China

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256313
Author(s):  
Bo Lan ◽  
Liping He ◽  
Yujing Huang ◽  
Xianhua Guo ◽  
Wenfeng Xu ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Level ◽  
Human Activities ◽  
Aquatic Ecosystem ◽  
Three Gorges Reservoir ◽  
Dominant Species ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Reservoir Area ◽  
The Three Gorges

To expand the knowledge on the tempo-spatial patterns of zooplankton and the key modulated factors in urban aquatic ecosystem, we investigated zooplankton and water quality from April 2018 to January 2019 in the hinterland of the Three Gorges Reservoir area, Wanzhou City of China. The results indicated that water quality indicated by the trophic state index (TSI) reached a state of mesotrophication to light eutrophication in the Yangtze River, and a state of moderate- to hyper- eutrophication in its tributaries. Based on the biomass of zooplanktons, Asplanchna priodonta was the most common specie in April; Encentrum sp., Filinia cornuta and Epiphanes senta were the most noticeable species in summer; Cyclopoida Copepodid, Sinocalanus dorrii and Philodina erythrophthalma became the dominant species in winter. Generally, rotifers prevailed in April and August, and copepods became the most popular in January. According to canonical correspondence analysis, nitrate, temperature (T), ammonia, water level and permanganate index (CODMn) significantly influenced the community structure of zooplankton (p < 0.05). The dominant species shifts of zooplankton were partly associated with nutrient level (nitrate and ammonia) under periodic water level fluctuations. Rotifers and protozoans were characterized as high T adapted and CODMn-tolerant species comparing with cladocerans and copepods. The ratio of microzooplankton to mesozooplankton (Pmicro/meso) has presented a strongly positive relationship with T (p < 0.001), as well as Pmicro/meso and CODMn (p < 0.001). It implied that zooplankton tended to miniaturize individual size via species shift under high T and/or CODMn conditions induced by global warming and human activities. The information hints us that climate change and human activities are likely to produce fundamental changes in urban aquatic ecosystem by reorganizing biomass structure of the food web in future.

scholarly journals Precipitation Changes in the Three Gorges Reservoir Area and the Relationship with Water Level Change

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6110
Author(s):  
Qin Li ◽  
Xiuguo Liu ◽  
Yulong Zhong ◽  
Mengmeng Wang ◽  
Manxing Shi
Keyword(s):  
Water Level ◽  
Three Gorges Reservoir ◽  
Precipitation Anomaly ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Reservoir Area ◽  
Precipitation Concentration ◽  
The Three Gorges ◽  
Before And After ◽  
Precipitation Changes

As the largest hydroelectric project worldwide, previous studies indicate that the Three Gorges Dam (TGD) affects the local climate because of the changes of hydrological cycle caused by the impounding and draining of the TGD. However, previous studies do not analyze the long-term precipitation changes before and after the impoundment, and the variation characteristics of local precipitation remain elusive. In this study, we use precipitation anomaly data derived from the CN05.1 precipitation dataset between 1988 and 2017 to trace the changes of precipitation before and after the construction of the TGD (i.e., 1988–2002 and 2003–2017), in the Three Gorges Reservoir Area (TGRA). Results showed that the annual and dry season precipitation anomaly in the TGRA presented an increasing trend, and the precipitation anomaly showed a slight decrease during the flood season. After the impoundment of TGD, the precipitation concentration degree in the TGRA decreased, indicating that the precipitation became increasingly uniform, and the precipitation concentration period insignificantly increased. A resonance phenomenon between the monthly average water level and precipitation anomaly occurred in the TGRA after 2011 and showed a positive correlation. Our findings revealed the change of local precipitation characteristics before and after the impoundment of TGD and showed strong evidence that this change had a close relationship with the water level.

The Discharge Outlets Layout Optimization of Typical River Section in the Three Gorges Reservoir Area

2014 ◽  
Vol 955-959 ◽  
pp. 3287-3294
Author(s):  
Zheng Wang ◽  
Ying Liu
Keyword(s):  
Water Quality ◽  
Three Gorges Reservoir ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Mixing Zone ◽  
Unit Load ◽  
Reservoir Area ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
The Impact

To improve water quality and alleviate pollution in Changshou-Fuling section of the Three Gorges Reservoir Area, an analysis methodology of regional key discharge outlet based on hydrodynamic-water quality model was developed. The EFDC model was used to study the impact of different discharge outlets on the transport of contamination in the study area by using the concept of pollutant mixing zone and pollutant mixing zone per unit load. Model calibration was conducted using observed data in 2008. Results indicated that EFDC could perfectly simulate hydrodynamics characteristics and contaminant transport process. Calculated results of pollutant mixing zone per unit load showed that the discharge outlet location in Fuling is more reasonable than that in Changshou. This study provides useful information for optimization of discharge outlets location and prediction of pollutant mixing zone in the study area, which is important for the government to make water pollution control measures.

scholarly journals The Coupling Effect of Rainfall and Reservoir Water Level Decline on the Baijiabao Landslide in the Three Gorges Reservoir Area, China

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Nenghao Zhao ◽  
Bin Hu ◽  
Qinglin Yi ◽  
Wenmin Yao ◽  
Chong Ma
Keyword(s):  
Water Level ◽  
Three Gorges Reservoir ◽  
Coupling Effect ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Reservoir Area ◽  
The Three Gorges ◽  
Water Level Decline

Rainfall and reservoir level fluctuation are two of the main factors contributing to reservoir landslides. However, in China’s Three Gorges Reservoir Area, when the reservoir water level fluctuates significantly, it comes at a time of abundant rainfall, which makes it difficult to distinguish which factor dominates the deformation of the landslide. This study focuses on how rainfall and reservoir water level decline affect the seepage and displacement field of Baijiabao landslide spatially and temporally during drawdown of reservoir water level in the Three Gorges Reservoir Area, thus exploring its movement mechanism. The monitoring data of the landslide in the past 10 years were analyzed, and the correlation between rainfall, reservoir water level decline, and landslide displacement was clarified. By the numerical simulation method, the deformation evolution mechanism of this landslide during drawdown of reservoir water level was revealed, respectively, under three conditions, namely, rainfall, reservoir water level decline, and coupling of the above two conditions. The results showed that the deformation of the Baijiabao landslide was the coupling effect of rainfall and reservoir water level decline, while the latter effect is more pronounced.

A correlation of pine wood nematode dispersal rate with human activities-a case study in the Three Gorges Reservoir Area

2017 ◽  
Vol 37 (20) ◽  
Author(s):  
洪承昊 HONG Chenghao ◽  
陈京元 CHEN Jingyuan ◽  
赵勇 ZHAO Yong ◽  
宋德文 SONG Dewen ◽  
陈桂芳 CHEN Guifang ◽  
...  
Keyword(s):  
Human Activities ◽  
Three Gorges Reservoir ◽  
Three Gorges Reservoir Area ◽  
Pine Wood Nematode ◽  
Three Gorges ◽  
Dispersal Rate ◽  
Reservoir Area ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

scholarly journals Landslide Characterization Applying Sentinel-1 Images and InSAR Technique: The Muyubao Landslide in the Three Gorges Reservoir Area, China

2020 ◽  
Vol 12 (20) ◽  
pp. 3385
Author(s):  
Chao Zhou ◽  
Ying Cao ◽  
Kunlong Yin ◽  
Yang Wang ◽  
Xuguo Shi ◽  
...  
Keyword(s):  
Water Level ◽  
Three Gorges Reservoir ◽  
In Situ Monitoring ◽  
Three Gorges Reservoir Area ◽  
Economic Losses ◽  
Landslide Monitoring ◽  
Three Gorges ◽  
Reservoir Area ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

Landslides are a common natural hazard that causes casualties and unprecedented economic losses every year, especially in vulnerable developing countries. Considering the high cost of in-situ monitoring equipment and the sparse coverage of monitoring points, the Sentinel-1 images and Interferometric Synthetic Aperture Radar (InSAR) technique were used to conduct landslide monitoring and analysis. The Muyubao landslide in the Three Gorges Reservoir area in China was taken as a case study. A total of 37 images from March 2016 to September 2017 were collected, and the displacement time series were extracted using the Stanford Method for Persistent Scatterer (StaMPS) small baselines subset method. The comparison to global positioning system monitoring results indicated that the InSAR processing of the Muyubao landslide was accurate and reliable. Combined with the field investigation, the deformation evolution and its response to triggering factors were analyzed. During this monitoring period, the creeping process of the Muyubao landslide showed obvious spatiotemporal deformation differences. The changes in the reservoir water level were the trigger of the Muyubao landslide, and its deformation mainly occurred during the fluctuation period and high-water level period of the reservoir.

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