Environmental influences on the spatio‐temporal distribution of Coilia nasus in the Yangtze River estuary

2020 ◽  
Vol 36 (3) ◽  
pp. 315-325
Author(s):  
Jin Ma ◽  
Bai Li ◽  
Jing Zhao ◽  
Xuefang Wang ◽  
Cameron T. Hodgdon ◽  
...  
Keyword(s):  
Yangtze River ◽  
Environmental Influences ◽  
River Estuary ◽  
Temporal Distribution ◽  
Yangtze River Estuary ◽  
The Yangtze River ◽  
Coilia Nasus ◽  
The Yangtze River Estuary ◽  
Spatio Temporal

Spatial–temporal distribution and fuzzy comprehensive evaluation of total phosphorus and total nitrogen in the Yangtze River Estuary

2015 ◽  
Vol 73 (4) ◽  
pp. 924-934 ◽  
Author(s):  
Ruimin Liu ◽  
Yaxin Chen ◽  
Wenwen Yu ◽  
Fei Xu ◽  
Zhenyao Shen
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Yangtze River ◽  
Comprehensive Evaluation ◽  
River Estuary ◽  
Temporal Distribution ◽  
Fuzzy Comprehensive Evaluation ◽  
Yangtze River Estuary ◽  
The Yangtze River ◽  
The Yangtze River Estuary

Based on water sample data collected from the Yangtze River Estuary (YRE) during four sampling periods in 2010 and 2011, the total nitrogen (TN) and total phosphorus (TP) content were evaluated using the traditional single-factor evaluation (TSE) and the fuzzy comprehensive evaluation (FCE). Statistical analyses showed that the average TN and TP for the four periods were 2.60 mg/L and 0.11 mg/L, respectively. August 2010 showed the lowest TN (1.57 mg/L), and February 2011 showed the highest TP (0.15 mg/L). The annual spatial distribution results indicated that an area of high TN concentration (TN ≥ 3.0 mg/L) occurred in the adjacent sea and increased on an eastward gradient. An area of high TP concentration (TP ≥0.10 mg/L) occurred in the inner YRE and decreased on an eastward gradient. There were significant differences in the results of TSE and FCE. The TSE results only reflected the TN evaluation results for certain locations of the YRE. The FCE method combined the effects of the TN and TP factors, and the results indicate that the Chinese water quality classification of Class 5 was dominant in the YRE.

Age structure and growth characteristics at seaward migrating periods of Anguilla japonica in the Yangtze River Estuary

2010 ◽  
Vol 34 (2) ◽  
pp. 245-254 ◽  
Author(s):  
Zheng-li XIE ◽  
Hong-yi GUO ◽  
Wen-qiao TANG ◽  
Kai WEI ◽  
Lin-hong SHEN ◽  
...  
Keyword(s):  
Age Structure ◽  
Yangtze River ◽  
River Estuary ◽  
Growth Characteristics ◽  
Anguilla Japonica ◽  
Yangtze River Estuary ◽  
The Yangtze River ◽  
The Yangtze River Estuary

scholarly journals Spatial and Temporal Variability of Soil Salinity in the Yangtze River Estuary Using Electromagnetic Induction

2021 ◽  
Vol 13 (10) ◽  
pp. 1875
Author(s):  
Wenping Xie ◽  
Jingsong Yang ◽  
Rongjiang Yao ◽  
Xiangping Wang
Keyword(s):  
Electrical Conductivity ◽  
Spatial Distribution ◽  
Soil Salinity ◽  
Yangtze River ◽  
Laboratory Data ◽  
River Estuary ◽  
Yangtze River Estuary ◽  
Soil Electrical Conductivity ◽  
The Yangtze River ◽  
The Yangtze River Estuary

Soil salt-water dynamics in the Yangtze River Estuary (YRE) is complex and soil salinity is an obstacle to regional agricultural production and the ecological environment in the YRE. Runoff into the sea is reduced during the impoundment period as the result of the water-storing process of the Three Gorges Reservoir (TGR) in the upper reaches of the Yangtze River, which causes serious seawater intrusion. Soil salinity is a problem due to shallow and saline groundwater under serious seawater intrusion in the YRE. In this research, we focused on the temporal variation and spatial distribution characteristics of soil salinity in the YRE using geostatistics combined with proximally sensed information obtained by an electromagnetic induction (EM) survey method in typical years under the impoundment of the TGR. The EM survey with proximal sensing method was applied to perform soil salinity survey in field in the Yangtze River Estuary, allowing quick determination and quantitative assessment of spatial and temporal variation of soil salinity from 2006 to 2017. We developed regional soil salinity survey and mapping by coupling limited laboratory data with proximal sensed data obtained from EM. We interpreted the soil electrical conductivity by constructing a linear model between the apparent electrical conductivity data measured by an EM 38 device and the soil electrical conductivity (EC) of soil samples measured in laboratory. Then, soil electrical conductivity was converted to soil salt content (soil salinity g kg−1) through established linear regression model based on the laboratory data of soil salinity and soil EC. Semivariograms of regional soil salinity in the survey years were fitted and ordinary kriging interpolation was applied in interpolation and mapping of regional soil salinity. The cross-validation results showed that the prediction results were acceptable. The soil salinity distribution under different survey years was presented and the area of salt affected soil was calculated using geostatistics method. The results of spatial distribution of soil salinity showed that soil salinity near the riverbanks and coastlines was higher than that of inland. The spatial distribution of groundwater depth and salinity revealed that shallow groundwater and high groundwater salinity influenced the spatial distribution characteristics of soil salinity. Under long-term impoundment of the Three Gorges Reservoir, the variation of soil salinity in different hydrological years was analyzed. Results showed that the area affected by soil salinity gradually increased in different hydrological year types under the impoundment of the TGR.

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