scholarly journals The Migration and Transformation of Nitrogen in the Danjiangkou Reservoir and Upper Stream: A Review

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2749
Author(s):  
Jin-Jin Li ◽  
Fei Dong ◽  
Ai-Ping Huang ◽  
Qiu-Yue Lian ◽  
Wen-Qi Peng
Keyword(s):  
Temporal Distribution ◽  
N Deposition ◽  
Water Diversion ◽  
Atmospheric N Deposition ◽  
N Cycle ◽  
Danjiangkou Reservoir ◽  
N Concentration ◽  
Spatial Differences ◽  
North Water ◽  
High Concentrations

The Danjiangkou Reservoir in China is characterized by significantly high concentrations of total nitrogen (TN), and the sources are not clear. Recently, research on this reservoir has focused on the N cycle, the spatial and temporal distribution characteristics of N, and the factors influencing N concentration. Significant temporal and spatial differences in TN concentrations exist, both in the reservoir area and the tributaries. N concentration in the area is affected by numerous factors, including N transported by tributaries, nonpoint source pollution around the reservoir, internal N release, and atmospheric N deposition. Moreover, a dam heightening project led to a larger water-fluctuation zone and more bays in the reservoir, directly affecting its N cycle. However, further research is required to explore the N cycle on a large watershed scale in the Danjiangkou Reservoir and upper stream areas, determine N pollution sources using satellite remote sensing, and conduct simulations of a water body N cycle model based on data fusion. Although the issue of excessive TN has been alleviated to some extent by the South-North Water Diversion Project, the excessively high TN concentrations require more research to aid the implementation of N-reducing strategies.

scholarly journals Detecting Water Diversion Fingerprints in the Danjiangkou Reservoir from Satellite Gravimetry and Altimetry Data

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3510
Author(s):  
Nengfang Chao ◽  
Gang Chen ◽  
Zhicai Luo ◽  
Xiaoli Su ◽  
Zhengtao Wang ◽  
...  
Keyword(s):  
Water Level ◽  
Water Storage ◽  
Water Diversion ◽  
Spatiotemporal Variability ◽  
Spatiotemporal Pattern ◽  
The South ◽  
Danjiangkou Reservoir ◽  
Water Diversion Project ◽  
North Water ◽  
And Storage

The Danjiangkou Reservoir (DJKR) is the freshwater source for the Middle Route of the South-to-North Water Diversion Project in China, and its water level and storage changes are important for water resource management. To maximize the potential capacity of the Gravity Recovery and Climate Experiment (GRACE) mission, an improved Lagrange multiplier method (ILMM) is first proposed to detect terrestrial water storage anomalies (TWSA) in the small-scale basin (DJKR). Moreover, for the first time, water diversion fingerprints are proposed to analyze the spatiotemporal pattern of the TWSA in the DJKR. The results indicate that the increased water level and storage signals due to the DJKR impoundment in 2014 can be effectively detected by using the ILMM, and they agree well with the results from altimetry and in situ data. Additionally, the water diversion fingerprints due to the DJKR impoundment are inferred, and describe the progression of spatiotemporal variability in water storage. The results show that water storage decreased in the upper Hanjiang River and increased in the DJKR as well as to the east of it during the period 2013–2015. Our research provides a scientific decision-making basis for monitoring the water resources of the DJKR and managing the South-to-North Water Diversion Project.

scholarly journals Numerical Simulations of Spread Characteristics of Toxic Cyanide in the Danjiangkou Reservoir in China under the Effects of Dam Cooperation

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Libin Chen ◽  
Zhifeng Yang ◽  
Haifei Liu
Keyword(s):  
Water Intake ◽  
Three Dimensional ◽  
Water Diversion ◽  
Quality Model ◽  
Toxic Pollutants ◽  
Danjiangkou Reservoir ◽  
Water Diversions ◽  
North Water ◽  
Reservoir Basin ◽  
Spread Speed

Many accidents of releasing toxic pollutants into surface water happen each year in the world. It is believed that dam cooperation can affect flow field in reservoir and then can be applied to avoiding and reducing spread speed of toxic pollutants to drinking water intake mouth. However, few studies investigated the effects of dam cooperation on the spread characteristics of toxic pollutants in reservoir, especially the source reservoir for water diversion with more than one dam. The Danjiangkou Reservoir is the source reservoir of the China’ South-to-North Water Diversion Middle Route Project. The human activities are active within this reservoir basin and cyanide-releasing accident once happened in upstream inflow. In order to simulate the spread characteristics of cyanide in the reservoir in the condition of dam cooperation, a three-dimensional water quality model based on the Environmental Fluid Dynamics Code (EFDC) has been built and put into practice. The results indicated that cooperation of two dams of the Danjiangkou Reservoir could be applied to avoiding and reducing the spread speed of toxic cyanide in the reservoir directing to the water intake mouth for water diversions.

scholarly journals Variations in nitrogen, phosphorus, and δ15N in Sphagnum mosses along a climatic and atmospheric deposition gradient in eastern Canada

Botany ◽  
2017 ◽  
Vol 95 (8) ◽  
pp. 829-839 ◽  
Author(s):  
Tatjana Živković ◽  
Kristina Disney ◽  
Tim R. Moore
Keyword(s):  
N:P Ratio ◽  
N Deposition ◽  
Atmospheric N Deposition ◽  
Eastern Canada ◽  
N Value ◽  
The North ◽  
P Concentration ◽  
N Concentration ◽  
N Acquisition ◽  
Deposition Gradient

We examined concentrations of nitrogen (N) and phosphorus (P) and δ15N value in Sphagnum sections Acutifolia and Cuspidata inhabiting hummocks and hollows from eight bogs along a transect from ∼45 to ∼55°N in Ontario and Quebec. The N concentration in Sphagnum declined from south to north, correlating with a decrease in atmospheric N deposition. Although the overall N concentration was larger in hollows than hummocks, the pattern was inconsistent across the sites. There was a proportionally larger decline in P concentration from south to north and an overall larger P concentration in hollows than hummocks, but there were inconsistent differences across the sites. The N:P ratio ranged from 12:1 to 29:1, driven primarily by the variation in P concentration. Ratios of N and P concentration in Sphagnum capitulum:stem averaged 1.2:1, suggesting nutrient resorption from stem to capitulum during growth; the ratio rose with increasing N and P concentration in the capitulum. The δ15N value of Sphagnum rose from ∼−6‰ in the south to ∼−1‰ in the north, correlated with the decrease in Sphagnum N concentration and with a rise in the water table. We interpret this to indicate a greater dependence on N2-fixation for N acquisition in the northern and wetter sites.

scholarly journals Spatio-Temporal Variation of Total Nitrogen and Ammonia Nitrogen in the Water Source of the Middle Route of the South-To-North Water Diversion Project

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2615
Author(s):  
Guoquan Dong ◽  
Zhenqi Hu ◽  
Xuan Liu ◽  
Yaokun Fu ◽  
Wenjing Zhang
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Total Nitrogen ◽  
Ammonia Nitrogen ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Water Diversion ◽  
Mountainous Area ◽  
Danjiangkou Reservoir ◽  
N Concentration

The quantitative inversion of the concentrations of water quality parameters could clarify the temporal and spatial distribution characteristic, migration, and conversion of water quality parameters. This study took the Danjiangkou Reservoir as the research object, and established an inversion model based on the reflectance of different band combinations of remote sensing analyses on Sentinel-2 images, combined with the water quality monitoring data of total nitrogen (TN) and ammonia nitrogen (NH3-N) of the sampling sites in February 2016. The inversion results of TN and NH3-N in 2020 were obtained, the variation of TN and NH3-N concentrations in the reservoir area were analyzed, and the factors accounting for the variation were discussed. The results indicated that the fitting accuracy using the established model was high for both TN and NH3-N, and R2 was 0.782 for TN and 0.851 for NH3-N, respectively, showing high predication accuracy, which could be suitable for remote sensing inversion of TN and NH3-N concentrations in the Danjiangkou Reservoir. The NH3-N concentration of the Danjiangkou Reservoir was in line with Class I from 2016 to 2020, while the TN concentration was between Class III and IV. The inter-annual changes indicated that the overall water quality had an upward trend. The main tributary in the northern of the Danjiangkou Reservoir had a heavy load of TN, and after entering the reservoir, the flow velocity decreased, which caused nitrogen to accumulate at the river entrance, leading to a high TN concentration. The large slope of the mountainous area cause soil erosion. The lost soil and water carried a large amount of pesticides and fertilizers, and the ground runoff carried a large amount of nitrogen into water body, which could account for the high NH3-N concentration on the east and west sides of the southern part of the Danjiangkou Reservoir.

Study on Impact of East Route Project of the South-to-North Water Diversion in China

2007 ◽  
Author(s):  
Yangwen Jia ◽  
Hong Gan ◽  
Jinjun You ◽  
Xueping Li ◽  
Cunwen Niu ◽  
...  
Keyword(s):  
Water Diversion ◽  
The South ◽  
North Water
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