Estimation of River Ecological Flow in the Downstream Section of Seomjingang Dam

2021 ◽  
Vol 28 (2) ◽  
pp. 1-13
Author(s):  
Jeonga Bae ◽  
Chanjoo Lee ◽  
Jin Kwan Kim
Keyword(s):  
Ecological Flow ◽  
Downstream Section

Establishing an empirical equation for the relationship between total suspended solids and total phosphorus concentrations in the downstream Red river water

2020 ◽  
Vol 20 (3) ◽  
pp. 325-332
Author(s):  
Le Nhu Da ◽  
Le Thi Phuong Quynh ◽  
Phung Thi Xuan Binh ◽  
Duong Thi Thuy ◽  
Trinh Hoai Thu ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Suspended Solids ◽  
Empirical Relationship ◽  
Water Environment ◽  
Total Suspended Solids ◽  
River System ◽  
Red River ◽  
Reservoir Impoundment ◽  
Downstream Section ◽  
Reasonable Prediction

Recently, the Asian rivers have faced the strong reduction of riverine total suspended solids (TSS) flux due to numerous dam/reservoir impoundment. The Red river system is a typical example of the Southeast Asian rivers that has been strongly impacted by reservoir impoundment in both China and Vietnam, especially in the recent period. It is known that the reduction in total suspended solids may lead to the decrease of some associated elements, including nutrients (N, P, Si) which may affect coastal ecosystems. In this paper, we establish the empirical relationship between total suspended solids and total phosphorus concentrations in water environment of the Red river in its downstream section from Hanoi city to the Ba Lat estuary based on the sampling campaigns conducted in the dry and wet seasons in 2017, 2018 and 2019. The results show a clear relationship with significant coefficient between total suspended solids and total phosphorus in the downstream Red river. It is expressed by a simple equation y = 0.0226x0.3867 where x and y stand for total suspended solids and total phosphorus concentrations (mg/l) respectively with the r2 value of 0.757. This equation enables a reasonable prediction of total phosphorus concentrations of the downstream Red river when the observed data of total suspended solids concentrations are available. Thus, this work opens up the way for further studies on the calculation of the total phosphorus over longer timescales using daily available total suspended solids values.

Variation analysis of streamflow and ecological flow for the twin rivers of the Miyun Reservoir Basin in northern China from 1963 to 2011

2015 ◽  
Vol 536 ◽  
pp. 739-749 ◽  
Author(s):  
Xuan Wang ◽  
Guangling Hao ◽  
Zhifeng Yang ◽  
Peiyu Liang ◽  
Yanpeng Cai ◽  
...  
Keyword(s):  
Northern China ◽  
Variation Analysis ◽  
Miyun Reservoir ◽  
Ecological Flow ◽  
Reservoir Basin

scholarly journals Characteristics and Practices of Ecological Flow in Rivers with Flow Reductions Due to Water Storage and Hydropower Projects in China

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1091 ◽  
Author(s):  
Lejun Ma ◽  
Xingnan Zhang ◽  
Huan Wang ◽  
Changjun Qi
Keyword(s):  
Calculation Method ◽  
River Flow ◽  
Water Storage ◽  
Engineering Calculation ◽  
Water Diversion ◽  
Western China ◽  
Flow Management ◽  
Riverine Ecosystems ◽  
Management Scheme ◽  
Ecological Flow

Water and flow reductions in the channels downstream of water storage and hydropower projects have significant impacts on aquatic ecosystems. Understanding and analyzing the ecosystem status is of great significance to facilitate the protection of riverine ecosystems. A database was established based on the 2000–2017 environmental impact assessment (EIA) reports on water storage and hydropower projects in China, and corresponding analysis software was built based on an ArcGIS spatial analysis platform. The projects in China are mainly found in the Yangtze and Pearl River basins and in south-western China. The hydropower projects have a larger influence than the water storage projects on the flow of downstream rivers sections, and most of the hydropower projects, especially the water diversion projects, cause flow reductions in the downstream rivers. An ecological flow management mechanism in China implemented in 2006 provided a promising method to alleviate river flow reductions. However, there is still only one kind of ecological flow calculation method and few ecological flow regulation measures in use. Based on the advantages and problems of the existing ecological flow management system, this paper proposes a management scheme based on a regional-engineering calculation method. The results can facilitate decision making in ecological flow management.

scholarly journals Modified frequency computation method for optimal environmental flows

2012 ◽  
Vol 16 (5) ◽  
pp. 1539-1543 ◽  
Author(s):  
Zhen-Hui Dong ◽  
Xiao-Hua Yang ◽  
Ya-Nan Guo ◽  
Ying Mei ◽  
Yu-Qi Li ◽  
...  
Keyword(s):  
Environmental Flows ◽  
Computation Method ◽  
Flow Method ◽  
Lancang River ◽  
Ecological Flow ◽  
Tennant Method

The paper describes a modified frequency computation method to calculate the optimal environmental flows. This method was used to design monthly environmental flows in Lancang river. The environmental flows calculated by the method are compared with those by the ecological flow method and the Tennant method, revealing its effectiveness.

scholarly journals Evaluation of Ecological Flow and Concentrations of Pollutants in Selected River Basin in Eastern Slovakia

2016 ◽  
Vol 162 ◽  
pp. 98-105 ◽  
Author(s):  
Vlasta Ondrejka Harbuľáková ◽  
Martina Zeleňáková ◽  
Martina Rysulová ◽  
Adam Repel ◽  
Dorota Simonová
Keyword(s):  
River Basin ◽  
Ecological Flow

APU-Noise Reduction by Novel Muffler Concepts

2018 ◽  
Author(s):  
Karsten Knobloch ◽  
Lars Enghardt ◽  
Friedrich Bake
Keyword(s):  
Noise Reduction ◽  
Operating Conditions ◽  
Acoustic Damping ◽  
Broadband Absorption ◽  
Auxiliary Power Unit ◽  
Auxiliary Power ◽  
Absorber Material ◽  
Bias Flow ◽  
Downstream Section ◽  
Broadband Sound

For a GTCP36-28 auxiliary power unit (APU), a set of mufflers has been designed and tested for some representative operating conditions. The first muffler design uses cavities of different sizes in conjunction with a bias flow for efficient broadband sound absorption. The second design — also expected to perform well over a large frequency range — makes use of a variable perforation and some porous absorber material. The acoustic damping performance of the mufflers was assessed using a downstream section of dedicated microphone probes. Individual spectra and circumferential averages have been computed and are used for a comparison to a hard-walled duct section of the same length. Results show a reasonable broadband absorption for most configurations. For one operating point, significant differences were found while comparing the performance of the cavity muffler with and without bias flow. The results suggest, that a small amount of air — less than initially expected — is sufficient to obtain the desired noise reduction.

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