scholarly journals Effects of a Proposed Hydraulic Project on the Hydrodynamics in the Poyang Lake Floodplain System, China

2021 ◽  
Vol 18 (15) ◽  
pp. 8072
Author(s):  
Guizhang Zhao ◽  
Yunliang Li
Keyword(s):  
Yangtze River ◽  
Poyang Lake ◽  
Critical Role ◽  
Storage Period ◽  
Flood Pulse ◽  
Water Levels ◽  
Flow Dynamics ◽  
Dam Construction ◽  
Hydrodynamic Effects ◽  
Vertical Scales

Knowledge of dam construction in floodplain systems and its hydrodynamic effects plays a critical role in managing various kinds of floodplains. This study uses 3D floodplain hydrodynamic modeling to explore the possible effects of a proposed hydraulic project in Poyang Lake (PLHP) on the hydrodynamics, exemplified by a large floodplain system. Simulations showed that the water levels across most lake regions presented more significant changes than in the floodplain areas during the study period. The increased water levels upstream from the PLHP (~1.0 m) were distinctly higher than that downstream (~0.1 m). The PLHP may decrease the magnitude of the water velocities in the main channels of the lake, whereas velocities may experience mostly minor changes in the floodplains, depending upon the altered flow dynamics and transport. On average, the water temperature may exhibit mostly minor changes (~<1.0 °C) for both the horizontal and vertical scales within the flood-pulse-influenced lake system. Additionally, the model results indicated that the outflow process caused by the PLHP may be altered from the natural discharge into the Yangtze River to frequent backflow events during the storage period, demonstrating the non-negligible effect of the PLHP on the water supply for the downstream Yangtze River in the future.

Effect of Three Gorges Reservoir on River-Connected Lakes in Central Yangtze River

2013 ◽  
Vol 726-731 ◽  
pp. 1305-1308
Author(s):  
L.Q. Dai ◽  
P.P. Zhang ◽  
J.Q. Mao ◽  
H.C. Dai
Keyword(s):  
Water Level ◽  
Yangtze River ◽  
Poyang Lake ◽  
Storage Period ◽  
Hydrological Regime ◽  
Water Release ◽  
Lake Water Level ◽  
Level Data ◽  
Before And After ◽  
Average Water

As a very critical indicator of the health of the lake, water level of the river-connected lakes is influenced by both watershed inflows and the mainstream. Lakes connected to the Yangtze River has showed big differences since the impoundment of the TGR in 2003, as the hydrological regime in central Yangtze River has changed a lot. In order to grasp the effect of the TGR on the river-connected lakes, based on the water level data of four typical stations in Poyang Lake during the water release operation and storage period before and after the impoundment, the variation of water level is compared and discussed. It is shown that water level of Poyang Lake has undergone changes. In the water release operation stage, the average water level is higher, but in the storage period from late September to October, the average water level of the lake lower than before. In addition, it is pointed out that the extent is gradually reduced from north to south, as the max influence water level is about 1.5 meters and the average influence water level is about 0.6 meters in Hukou station. However, considering the time since the dam n period has not been long, the reservoir effect still needs to be further assessed based on long-term monitoring.

scholarly journals Differences of Regulative Flexibility between Hydrological Isolated and Connected Lakes in a Large Floodplain: Insight from Inundation Dynamics and Landscape Heterogeneity

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 991
Author(s):  
Jiakun Teng ◽  
Shaoxia Xia ◽  
Yu Liu ◽  
Peng Cui ◽  
Jiang Chen ◽  
...  
Keyword(s):  
Habitat Quality ◽  
Yangtze River ◽  
Vegetation Index ◽  
Poyang Lake ◽  
Wetland Management ◽  
Google Earth ◽  
Dongting Lake ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Jianghan Plain

The inundation areas of floodplains are crucial to wetland ecosystems, especially in supporting biodiversity. Accurately identifying the spatial and temporal patterns of inundation areas is important for understanding floodplain ecosystem processes. Here, lakes in the Yangtze River Floodplain were divided into two types according to hydrological conditions: the natural connected lakes (Dongting Lake and Poyang Lake) with natural water level fluctuations and the isolated lakes (lakes in Jianghan Plain) with stable water levels. We established a method to identify inundation areas using multi-sources remote sensing data based on the Google Earth Engine. The dynamics of inundation areas were determined, and the relative indices were calculated in common year (2017) and a drought year (2018). The differences between the connected lakes and the isolated lakes were analyzed, and impacts of hydrological fluctuations on inundation area and habitat quality were evaluated. The results show that lakes with natural hydrological fluctuations have a greater regulative flexibility, with both patch density (PD) and submerged elasticity index (SEI) values higher than that of isolated lakes. The trend of the vegetation index in the connected lakes and in the isolated lakes is also different. The mean EVI in Dongting Lake and Poyang Lake showed a U-shaped trend which is similar to the shape of the trend of PD. The trend of mean enhanced vegetation index (EVI) in the isolated lakes is the opposite and has a lower range of variation over a year. This study provides new indicators and rapid methods for habitat quality assessment in floodplains, as well as presenting scientific information useful for improving wetland management in the middle and lower Yangtze River.

Impact of lake inflow and the Yangtze River flow alterations on water levels in Poyang Lake, China

2014 ◽  
Vol 30 (4) ◽  
pp. 321-330 ◽  
Author(s):  
Xijun Lai ◽  
Qun Huang ◽  
Yinghao Zhang ◽  
Jiahu Jiang
Keyword(s):  
Yangtze River ◽  
River Flow ◽  
Poyang Lake ◽  
Water Levels ◽  
The Yangtze River

scholarly journals Hydrological evidence and causes of seasonal low water levels in a large river-lake system: Poyang Lake, China

2016 ◽  
Vol 47 (S1) ◽  
pp. 24-39 ◽  
Author(s):  
Jing Yao ◽  
Qi Zhang ◽  
Yunliang Li ◽  
Mengfan Li
Keyword(s):  
Yangtze River ◽  
Water Resource Management ◽  
Poyang Lake ◽  
Large River ◽  
Water Levels ◽  
The Yangtze River ◽  
Lake System ◽  
Spatial Differences ◽  
Northern Portion ◽  
Lake Systems

Seasonal variations in local catchments and connected rivers lead to complex hydrological behaviours in river-lake systems. Poyang Lake is a seasonally dynamic lake with frequent low levels in spring and autumn, which may be triggered by the local catchment and Yangtze River. Based on two typical years, a hydrodynamic model combined with long term hydrological observations was applied to quantify the spatiotemporal impacts of the local catchment and Yangtze River on spring and autumn low water levels in Poyang Lake. As a first attempt, this study explored the spatial differences of the two influences. Simulation results showed that the contributions of the catchment and the Yangtze River were approximately 70% and 30% in spring 1963, and 5% and 95% in autumn 2006, respectively. The area of catchment influence was mainly distributed in channels and southern floodplains, with relatively uniform water levels. The area impacted by the Yangtze River mainly spanned from the northern portion of the waterway to the central lake, with strong spatial variability. This study focused on two typical years; however, the results can be extended to explain common hydrological phenomena and improve future strategies of water resource management in this river-lake system.

scholarly journals Investigating a complex lake-catchment-river system using artificial neural networks: Poyang Lake (China)

2015 ◽  
Vol 46 (6) ◽  
pp. 912-928 ◽  
Author(s):  
Y. L. Li ◽  
Q. Zhang ◽  
A. D. Werner ◽  
J. Yao
Keyword(s):  
Water Level ◽  
Lake Water ◽  
Yangtze River ◽  
Poyang Lake ◽  
Multiple Stressors ◽  
Resource Planning ◽  
Water Levels ◽  
The Yangtze River ◽  
Large Lake ◽  
Lake Catchment

Lake hydrological simulations using physically based models are cumbersome due to extensive data and computational requirements. Despite an abundance of previous modeling investigations, real-time simulation tools for large lake systems subjected to multiple stressors are lacking. The back-propagation neural network (BPNN) is applied as a first attempt to simulate the water-level variations of a large lake, exemplified by the Poyang Lake (China) case study. The BPNN investigation extends previous modeling efforts by considering the Yangtze River effect and evaluating the influence of the Yangtze River on the lake water levels. Results indicate that the effects of both the lake catchment and the Yangtze River are required to produce reasonable BPNN calibration statistics. Modeling results suggest that the Yangtze River plays a significant role in modifying the lake water-level changes. Comparison of BPNN models to a 2D hydrodynamic model (MIKE 21) shows that comparable accuracies can be obtained from both modeling approaches. This implies that the BPNN approach is well suited to long-term predictions of the water-level responses of Poyang Lake. The findings of this work demonstrate that BPNN can be used as a valuable and computationally efficient tool for future water resource planning and management of the Poyang Lake.

scholarly journals Comparison of the Hydrological Dynamics of Poyang Lake in the Wet and Dry Seasons

2021 ◽  
Vol 13 (5) ◽  
pp. 985
Author(s):  
Fangdi Sun ◽  
Ronghua Ma ◽  
Caixia Liu ◽  
Bin He
Keyword(s):  
Yangtze River ◽  
Poyang Lake ◽  
River System ◽  
Water Levels ◽  
Lake Area ◽  
Lake Surface ◽  
Volume Changes ◽  
Average Value ◽  
Dry Seasons ◽  
Wet And Dry Seasons

Poyang Lake is the largest freshwater lake connecting the Yangtze River in China. It undergoes dramatic dynamics from the wet to the dry seasons. A comparison of the hydrological changes between the wet and dry seasons may be useful for understanding the water flows between Poyang Lake and Yangtze River or the river system in the watershed. Gauged measurements and remote sensing datasets were combined to reveal lake area, level and volume changes during 2000–2020, and water exchanges between Poyang Lake and Yangtze River were presented based on the water balance equation. The results showed that in the wet seasons, the lake was usually around 1301.85–3840.24 km2, with an average value of 2800.79 km2. In the dry seasons, the area was around 618.82–2498.70 km2, with an average value of 1242.03 km2. The inundations in the wet seasons were approximately quadruple those in the dry seasons. In summer months, the lake surface tended to be flat, while in winter months, it was inclined, with the angles at around 10′′–16′′. The mean water levels of the wet and dry seasons were separately 13.51 m and 9.06 m, with respective deviations of around 0–2.38 m and 0.38–2.15 m. Monthly lake volume changes were about 7.5–22.64 km3 and 1–5.80 km3 in the wet and dry seasons, respectively. In the wet seasons, the overall contributions of ground runoff, precipitation on the lake surface and lake evaporation were less than the volume flowing into Yangtze River. In the dry seasons, the three contributions decreased by 50%, 50% and 65.75%, respectively. Therefore, lake storages presented a decrease (−7.42 km3/yr) in the wet seasons and an increase (9.39 km3/yr) in the dry seasons. The monthly exchanges between Poyang Lake and Yangtze River were at around −14.22–32.86 km3. Water all flowed from the lake to the river in the wet seasons, and the chance of water flowing from Yangtze River in the dry seasons was only 5.26%.

scholarly journals Mollusc fisheries and length–weight relationship in Tonle Sap flood pulse system, Cambodia

2018 ◽  
Vol 54 ◽  
pp. 34 ◽  
Author(s):  
Peng Bun Ngor ◽  
Ratha Sor ◽  
Leang Hour Prak ◽  
Nam So ◽  
Zeb S. Hogan ◽  
...  
Keyword(s):  
Annual Variation ◽  
Flood Pulse ◽  
Growth Patterns ◽  
Water Levels ◽  
Relationship Analysis ◽  
Weight Relationship ◽  
Daily Data ◽  
Tonle Sap ◽  
Mollusc Species ◽  
One Year

Molluscs are important for ecological function, livelihoods and fisheries, but are often forgotten in research and management. Here, we investigated intra-annual variation in the landing and growth patterns of three mollusc species, i.e., Corbicula moreletiana, Pila virescens and Pila ampullacea, using one-year daily data on landing catches and values, recorded in Kampong Chhnang province of Tonle Sap (TS) Lake. Overall, 8330 tonnes with a first sale landing value of US$ 1.4 million for the three species were reported. Also, we found that C. moreletiana was abundant during the dry season with high temperature and less precipitation. By contrast, the two Pila species were abundant from the early rainy to early dry seasons when precipitation and water levels increase. The length–weight relationship analysis indicated that a faster growth in weight of Pila species occurred in the rainy season, and a general negative allometric growth was observed for the three species. This implies that their populations were intensively fished. Our preliminary results suggest that molluscs in the TS Lake (i) are important resources in support of people's livelihoods, (ii) respond differently to intra-annual variation in temperature, precipitation and hydrology and (iii) are being intensively exploited with significant reduction in growth rate. Therefore, it is necessary to conduct further comprehensive research describing status of mollusc stocks and their ecology to support long-term management and conservation of this important aquatic fauna. Our study contributes to establishing the first important baseline data and information on key mollusc species for the TS.

scholarly journals Changes in composition of aquatic bird assemblages associated with changing in water levels in the Aquatic Terrestrial Transitional Zone of the Pantanal wetland Brazil

2020 ◽  
Vol 9 (10) ◽  
pp. e4479108555
Author(s):  
Josué Ribeiro da Silva Nunes ◽  
Carolina Joana da Silva ◽  
Solange Kimie Ikeda-Castrillon ◽  
Nilo Leal Sander
Keyword(s):  
Aquatic Macrophyte ◽  
Transitional Zone ◽  
High Water ◽  
Flood Pulse ◽  
Water Levels ◽  
Aquatic Birds ◽  
Mato Grosso ◽  
Paraguay River ◽  
The Difference ◽  
Pantanal Wetland

The Pantanal wetland Mato Grosso, Brazil is among the largest floodplains in the world, with a mosaic of different habitats and rich aquatic and terrestrial biota. The habitat mosaics are found in the Chacororé and Sinhá Mariana lake System. These parental lakes of the Cuiabá River, a left tributary of the Upper Paraguay River, are known for their aquatic productivity and scenic beauty. The characteristics of these lakes and their floodplains are showed through the difference between their waters, the diversity of the aquatic macrophytes communities, fish communities and aquatic birds. Our study looked at changes in limnological variables as well as diversity of aquatic birds, during high water or flooded phase; medium water or receding phase; and the low water or dry phase. We used a temporary small lagoon in the floodplain of this system as our study area. The flood pulse is the main ecological factor affecting the Pantanal; it modifies ecological process and species composition. The water depth decreases during the season, decreasing electrical conductivity, dissolved phosphate and nitrate, water transparency, dissolved oxygen and biomass of aquatic macrophyte; and increasing calcium, total phosphorus and total nitrogen. We also observed increase in species richness and abundance of aquatic birds during the receding phase. Results show that the number of species (density) of aquatic birds increased from 10 to 30 species and the numbers of individuals from 40 to 936. The maximum richness and abundance of aquatic birds was registered during the receding phase.

PRELIMINARY ANALYSIS OF HYDRODYNAMICS AND WATER CHEMISTRY AT THE CONFLUENCE OF YANGTZE RIVER AND POYANG LAKE, CHINA

2019 ◽  
Author(s):  
KUN LI ◽  
SAIYU YUAN ◽  
HONGWU TANG ◽  
SHUJUN HUANG ◽  
YANG XIAO ◽  
...  
Keyword(s):  
Water Chemistry ◽  
Preliminary Analysis ◽  
Yangtze River ◽  
Poyang Lake
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