A C-vine copula framework to predict daily water temperature in the Yangtze River

2021 ◽  
pp. 126430
Author(s):  
Yuwei Tao ◽  
Yuankun Wang ◽  
Dong Wang ◽  
Lingling Ni ◽  
Jichun Wu
Keyword(s):  
Water Temperature ◽  
Yangtze River ◽  
The Yangtze River ◽  
Daily Water Temperature ◽  
Daily Water ◽  
Vine Copula

Experimental Studies on the Thermal Performance of the Balcony-Type Flat-Plate Solar Water Heater

2014 ◽  
Vol 953-954 ◽  
pp. 111-114
Author(s):  
Sheng Xian Wei ◽  
Fen E Hu ◽  
Dong Yu Li ◽  
Hui Li
Keyword(s):  
Water Temperature ◽  
Flat Plate ◽  
Temperature Rise ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Water Heating ◽  
Solar Water Heating ◽  
Solar Water ◽  
Daily Water Temperature ◽  
Daily Water

Based on the test methods for solar water heating systems, the unsteady thermal efficiency, the daily thermal efficiency and the daily water temperature rise of the balcony-type solar water heating system with a flat-plate solar collector fixed at a large tilt angle (≥60o) have been discussed by the experimental test in Kunming. The results indicate that the average daily thermal efficiencies of the solar collector installed at 60o, 70o, 80o and 90o are around 0.35, 0.39, 0.34 and 0.40. The intercept and the slope of the unsteady thermal efficiency equations are about 0.36~0.44 and 1.62~4.01W·°C-1·m-2. The average daily water temperature rise is 25.2°C, 20.1°C, 18.2°C and 17.4°C for the solar collector fixed at 60o, 70o, 80o and 90o.

scholarly journals Driving Factors and Dynamics of Phytoplankton Community and Functional Groups in an Estuary Reservoir in the Yangtze River, China

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1184 ◽  
Author(s):  
Changtao Yang ◽  
Jing Nan ◽  
Jianhua Li
Keyword(s):  
Water Temperature ◽  
Functional Groups ◽  
Yangtze River ◽  
Light Availability ◽  
Ecological Status ◽  
Water Source ◽  
Driving Factors ◽  
Nutrient Concentrations ◽  
Drinking Water Source ◽  
The Yangtze River

Qingcaosha Reservoir, an estuary reservoir on the Yangtze River and a drinking water source, is facing phytoplankton blooms and the factors driving changes in phytoplankton composition and distribution have not been well understood so far. To facilitate the understanding of this problem, we collected surface water samples from January to December 2014 monthly at 12 sampling sites. A total of 205 taxa classified into eight major taxonomic groups were identified. Cyclotella meneghiniana, Melosira varians, Melosira granulata, Cryptomonas ovata and Chlorella vulgaris were the species dominating at least one season. The long stratification period and high nutrient concentration resulted in high chlorophyll a concentration (36.1 ± 18.5 μg L−1) in the midstream and downstream during summer, and mass phytoplankton growth and sedimentation process led to nutrients decrease. In the reservoir, neither P or N limitation was observed in the study period. We observed that water temperature, nutrient concentrations and light availability (Zeu/Zmix) are critical in selecting functional groups. These results highlight that the functional groups characterized the water body well and showed a good ecological status based on the assemblage index (Q average = 4.0). This work also highlights that mixing regime, water temperature and light availability were the driving factors that determine phytoplankton dynamics.

Growth modelling in accordance with daily water temperature in European grayling (Thymallus thymallusL.)

1999 ◽  
Vol 56 (6) ◽  
pp. 994-1000 ◽  
Author(s):  
J P Mallet ◽  
S Charles ◽  
H Persat ◽  
P Auger
Keyword(s):  
Growth Rate ◽  
Water Temperature ◽  
Good Description ◽  
Biological Significance ◽  
Temperature Fluctuations ◽  
Fish Growth ◽  
Von Bertalanffy ◽  
European Grayling ◽  
Daily Water Temperature ◽  
Daily Water

The model of von Bertalanffy has been and is still widely used to model fish growth, mainly because of its good description of annual growth over the whole life span. However, it does not take into account a seasonal variability in growth rate, an important phenomenon that appears quite well correlated with water temperature fluctuations in temperate climates. In the present study, we demonstrated that it was possible to model such variations by including daily water temperature in the von Bertalanffy growth formula owing to the correlation between the growth coefficient k and water temperature. The model we chose to describe such a correlation includes parameters with obvious biological significance and is mathematically well structured, which allowed an extensive use of our growth model. Hence, we use our new model to describe annual variability in the growth of European grayling (Thymallus thymallus L.) in a river section where water temperature could rise up to the thermal tolerance limit for this species, inducing reduced growth rates and severe mortality events. Finally, we were able to explain the growth rate variability from one year to the next by interannual water temperature fluctuations.

Preliminary observations of migrating adult freshwater eels (Anguilla australis australis Richardson) in Tasmania

1984 ◽  
Vol 35 (4) ◽  
pp. 471 ◽  
Author(s):  
RD Sloane
Keyword(s):  
Water Temperature ◽  
Significant Positive Correlation ◽  
River Flow ◽  
Downstream Migration ◽  
Single Male ◽  
Male Specimen ◽  
Anguilla Australis ◽  
Daily Water Temperature ◽  
Daily Water ◽  
Freshwater Eels

The downstream migration of maturing adult short-finned eels, A. a. australis, was recorded at an eel trap on the Clyde River during the 1981-1982 season. 5.2 t of eels entered the trap from November to April with 53% of the catch taken during January. Of the 190 eels examined, only a single male specimen was found. Female A. a. australis migrated downstream at a mean length of 94.5 cm, a mean weight of 1700 g and a mean age of 22.1 years (range 18-30 years). There was a significant positive correlation between catch and water temperature, temperatures above 12�C being associated with eel migration. The peak catch occurred during January and coincided with the highest record of mean daily water temperature (20.5�C). The migration did not appear to be influenced by moon phase, and river flow was controlled.

Longitudinal recovery gradients of drifting larval fish assemblages in the middle reach of the Yangtze River: impact of the Three Gorges Dam and conservation implementation

2019 ◽  
Vol 76 (12) ◽  
pp. 2256-2267 ◽  
Author(s):  
Yiqing Song ◽  
Fei Cheng ◽  
Peng Ren ◽  
Zhen Wang ◽  
Songguang Xie
Keyword(s):  
Water Temperature ◽  
Yangtze River ◽  
Fish Assemblages ◽  
Larval Fish ◽  
Three Gorges ◽  
The Yangtze River ◽  
River Section ◽  
Middle Reach ◽  
The Three Gorges ◽  
The Three Gorges Dam

Drifting larval fish assemblages were investigated at three sections in the middle reach of the Yangtze River downstream of the Three Gorges Dam to reveal recovery gradients and to identify the major environmental factors influencing their temporal and spatial patterns. Larval fish in the river section closest to the dam showed lower abundance, later occurrence, narrower temporal niche breadth, and more pairs of dominant species with high niche overlap than those further from the dam. Water temperature, transparency, and discharge significantly influenced the larval fish assemblages. They showed longitudinal gradients of increased water temperature, decreased transparency, and increased discharge in a downstream direction. Our results suggested that hypolimnetic and clean water discharge from the dam heavily impacted larval fish assemblage in the river section near the dam. With an increased distance to the dam and the input of some major tributaries, this impact was gradually buffered, thus forming the longitudinal recovery gradients. We suggest that priority for conservation should shift from river sections closer to the dam to those further from the dam.

Performance Analysis of Integrated Collector System with Immersed Coil Heat Exchanger

2014 ◽  
Vol 660 ◽  
pp. 740-744 ◽  
Author(s):  
Lukmon Owolabi Afolabi ◽  
Hussain Hamoud Al-Kayiem ◽  
Tesfamichael Baheta Aklilu
Keyword(s):  
Heat Exchanger ◽  
Water Temperature ◽  
System Efficiency ◽  
Daily Water Temperature ◽  
Solar Intensity ◽  
Collector Efficiency ◽  
Daily Water ◽  
The Mean ◽  
Coil Heat Exchanger ◽  
Coil Heat

The performance of integrated solar collector / thermal energy storage with immersed heat exchanger was investigated experimentally at the Solar Research Site, University Technology PETRONAS, (4.4224oN, 100.9904oE), Malaysia. The experimental set up consisted of 150 liters storage tank capacity with immersed coil heat exchanger, single glazing 1.5m2 flat plate collector with 15o tilt to the horizontal. The circulation of the working fluid was by forced in closed loop with a mini solar pump. Aluminum cell foam was attached to the absorber as extended surface. The surface of the collector was coated with black ornament to improve its absorption. The system was tested under clear skys, for two cases; with and without water drawn-off for seven days per case studied. The performance evaluation data obtained for case1 at the mean maximum solar intensity was 503.98 W/m2 were: maximum daily water temperature 63°C, average daily water temperature 46°C, collector efficiency 63% and system efficiency 43%. Whilst for case 2, the mean maximum solar intensity was 473.11 W/m2, the maximum daily water temperature 54°C, average daily water temperature 39.36°C, collector efficiency 54% and system efficiency 39%. The system efficiency for case 2 showed that the heat exchanger performed slighlty better and the water drawn-off effect is minimal.

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