scholarly journals Research on water environmental capacity accounting of the Yongzhou Section of Xiangjiang River Basin based on the SWAT-EFDC coupling model

2021 ◽  
Author(s):  
Li Wu ◽  
Zhe Chen ◽  
Xuan Ding ◽  
Hui-ying Liu ◽  
Dun-qiu Wang
Keyword(s):  
Water Quality ◽  
River Basin ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Coupling Model ◽  
Theoretical Formula ◽  
Environmental Capacity ◽  
Xiangjiang River ◽  
Water Environmental Capacity ◽  
Xiangjiang River Basin

Abstract In this paper, a coupling model of SWAT (Soil and Water Assessment Tool) and EFDC (Environmental Fluid Dynamics Code) was established, and the relationship between the pollution source and water quality response was identified. Based on the hydrodynamic water quality simulation results and the one-dimensional WEC (water environmental capacity) theoretical formula, the total nitrogen and total phosphorus WEC and the remaining WEC of the Yongzhou Section of Xiangjiang River Basin under the guaranteed rate of 90% and in 2017 were calculated, respectively. It can be seen from the results that the total nitrogen WEC of the Yongzhou Section of Xiangjiang River Basin in 2017 is 27,673.04 t, the total nitrogen WEC under the guaranteed rate of 90% is 19,497.61 t/a and the total phosphorus WEC of the Yongzhou Section of Xiangjiang River Basin in 2017 is 4,877.22 t. The total phosphorus WEC under the guaranteed rate of 90% is 2,936.64 t/a; in 2017, the remaining WECs of total nitrogen and total phosphorus in the entire basin are 14,646.69 and 3,358.67 t, respectively.

scholarly journals Analysis on the evolution trend of water resources and water environment in Xiangjiang River basin

2018 ◽  
Vol 246 ◽  
pp. 02030
Author(s):  
Xingyi Xu ◽  
Chuqiu Xiao ◽  
Chunyan Hu ◽  
Guiyuan Li ◽  
Xiang Gao ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
River Basin ◽  
Water Environment ◽  
Sudden Change ◽  
Xiangjiang River ◽  
Flood Season ◽  
Xiangjiang River Basin ◽  
Evolution Trend

According to the daily flow data collected by three representative hydrological stations in the Xiangjiang River basin which are the Guiyang station in the upstream section, the Hengshan station in the midstream section, and the Xiangtan station in the downstream section, and the water environment data collected from the Hunan Water Resources Bulletin, Mann-Kendal method was used to analyze the changes of the annual average flow of the Xiangjiang River basin in the past 20 years as well as the variation of water environment quality in the whole year, flood season and non-flood season. Based on these analysis, the evolution trend of water resources and water environment in the Xiangjiang River basin is further forecasted. The results show that the annual runoff of the upper reaches of the Xiangjiang River basin tends to be stable, and the runoff of the middle and lower reaches is decreasing. The water quality of the Xiangjiang River basin got deteriorated from 1996 to 2010. A sudden change occurred around 2012, and the water quality of the basin gradually improved.

scholarly journals Effect of red algal bloom on growth and production of carps

Our Nature ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 48-54
Author(s):  
Ram Bhajan Mandal ◽  
Sunila Rai ◽  
Madhav Kumar Shrestha ◽  
Dilip Kumar Jha ◽  
Narayan Prasad Pandit
Keyword(s):  
Water Quality ◽  
Body Weight ◽  
Chlorophyll A ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Algal Bloom ◽  
Total Dissolved Solids ◽  
Dissolved Solids ◽  
Aquaculture Farm ◽  
Red Algal

An experiment was carried to assess the effect of red algal bloom on growth and production of carp, water quality and profit from carp for 120 days at Aquaculture Farm of Agriculture and Forestry University, Chitwan. The experiment included two treatments: carp polyculture in non-red pond and carp polyculture in red pond with algal bloom each with three replicates. Carp fingerlings were stocked at 1 fish/m2 and fed with pellet containing 24% CP at 3% body weight. Net yield of rohu was found significantly higher (p<0.05) in non-red ponds (0.38±0.01 t ha-1) than red ponds (0.24±0.05 t ha-1). Survival of rohu (84.9±1.4%), bighead (95.2±2.0%) and mrigal (88.1±14.4%) were also significantly higher (p<0.05) in non-red ponds than red ponds. Red algal bloom affected DO, nitrate and chlorophyll-a, nitrite, total nitrogen, total phosphorus, total dissolved solids and conductivity. However, overall carp production and profit from carp remained unaffected.

scholarly journals Quality of surface water related to land use: a case study in a catchment with small farms and intensive vegetable crop production in southern Brazil

2014 ◽  
Vol 38 (2) ◽  
pp. 656-668 ◽  
Author(s):  
Karina Hacke Ribeiro ◽  
Nerilde Favaretto ◽  
Jeferson Dieckow ◽  
Luiz Cláudio de Paula Souza ◽  
Jean Paolo Gomes Minella ◽  
...  
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Land Use ◽  
Surface Water ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Oxygen Demand ◽  
Lower Percentage ◽  
Native Forest ◽  
Particulate Nitrogen

Water degradation is strongly related to agricultural activity. The aim of this study was to evaluate the influence of land use and some environmental components on surface water quality in the Campestre catchment, located in Colombo, state of Parana, Brazil. Physical and chemical attributes were analyzed (total nitrogen, ammonium, nitrate, total phosphorus, electrical conductivity, pH, temperature, turbidity, total solids, biological oxygen demand, chemical oxygen demand and dissolved oxygen). Monthly samples of the river water were taken over one year at eight monitoring sites, distributed over three sub-basins. Overall, water quality was worse in the sub-basin with a higher percentage of agriculture, and was also affected by a lower percentage of native forest and permanent preservation area, and a larger drainage area. Water quality was also negatively affected by the presence of agriculture in the riparian zone. In the summer season, probably due to higher rainfall and intensive soil use, a higher concentration of total nitrogen and particulate nitrogen was observed, as well as higher electrical conductivity, pH and turbidity. All attributes, except for total phosphorus, were in compliance with Brazilian Conama Resolution Nº 357/2005 for freshwater class 1. However, it should be noted that these results referred to the base flow and did not represent a discharge condition since most of the water samples were not collected at or near the rainfall event.

Assessment of Freshwater Inflow and Water Quality for an Urbanized, Subtropical Estuary (Lake Worth Lagoon, Florida, USA)

2018 ◽  
Vol 52 (4) ◽  
pp. 19-31
Author(s):  
Christopher Buzzelli ◽  
Zhiqiang Chen ◽  
Peter Doering ◽  
Amanda Kahn
Keyword(s):  
Water Quality ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Suspended Solids ◽  
Environmental Parameters ◽  
Total Suspended Solids ◽  
South Florida ◽  
Freshwater Inflow ◽  
Spatial And Temporal Variability ◽  
Palm Beach County

Abstract Coastal water bodies are impacted by watershed alterations, increased population density, modifications to inlets and shorelines, climatic periodicity, and increases in external material loads. Estuaries such as Lake Worth Lagoon (LWL) in south Florida possess all these attributes. The LWL watershed extends from the southeastern portion of Lake Okeechobee through Palm Beach County, where it meets the lagoon. Palm Beach County Department of Environmental Resources Management recognizes the social and ecological importance of the ~36 km lagoon and aims to maintain suitable water and habitat quality for all stakeholders. Recent declines and shifts of seagrass distribution along the lagoon prompted a step toward better understanding the water quality patterns of the system. In support of these efforts, this study assessed bathymetry, inflow, flushing, and water quality attributes (chlorophyll a, salinity, total nitrogen, total phosphorus, total suspended solids, turbidity) using data collected along a series of 14 midlagoon stations from 2007 to 2015. Salinity in the North Segment was higher and less variable because of proximity to Palm Beach Inlet. Although concentrations of chlorophyll a, total nitrogen, and total phosphorus correlated with freshwater inflow, turbidity and total suspended solids were not. Fast flushing of the lagoon on a scale of days likely precludes water quality issues common to many estuaries with higher resident times. However, the combination of landscape-scale water management, a shoreline that is almost 70% modified by hard structures, and changes in essential nearshore habitats, introduces new levels of uncertainty to both the understanding and management of LWL. From this study, increased knowledge of relationships among water quality parameters and their spatial and temporal variability in LWL provides points of reference from which targeted studies can be developed to explore links between environmental parameters and responses of key organisms in this unique system.

scholarly journals Water Supply-Water Environmental Capacity Nexus in a Saltwater Intrusion Area under Nonstationary Conditions

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 346
Author(s):  
Dedi Liu ◽  
Yujie Zeng ◽  
Yue Qin ◽  
Youjiang Shen ◽  
Jiayu Zhang
Keyword(s):  
Water Quality ◽  
Water Supply ◽  
Saltwater Intrusion ◽  
Water Environment ◽  
Environmental Capacity ◽  
Freshwater Flow ◽  
Environment Capacity ◽  
Water Environmental Capacity ◽  
Water Environment Capacity ◽  
Supply Water

Due to water supply increase and water quality deterioration, water resources are a critical problem in saltwater intrusion areas. In order to balance the relationship between water supply and water environment requirements, the nexus of water supply-water environment capacity should be well understood. Based on the Saint–Venant system of equations and the convection diffusion equation, the water supply-water environment capacity nexus physical equation is determined. Equivalent reliability is employed to estimate the boundary design water flow, which will then lead to a dynamic nexus. The framework for determining the nexus was then applied to a case study for the Pearl River Delta in China. The results indicate that the water supply-water environment capacity nexus is a declining linear relationship, which is different from the non-salt intrusion and tide-impacted areas. Water supply mainly relies on freshwater flow from upstream, while water environmental capacity is affected by both the design freshwater flow and the water levels at the downstream boundary. Our methods provide a useful framework for the quantification of the physical nexus according to the water quantity and water quality mechanisms, which are useful for freshwater allocation and management in a saltwater intrusion area or the tail area of cascade reservoirs.

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