scholarly journals Incorporation of the simplified equilibrium temperature approach in a hydrodynamic and water quality model – CE-QUAL-W2

2018 ◽  
Vol 19 (1) ◽  
pp. 156-164 ◽  
Author(s):  
Senlin Zhu ◽  
Xinzhong Du ◽  
Wenguang Luo
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Process Model ◽  
Oxygen Demand ◽  
Equilibrium Temperature ◽  
Coefficient Of Determination ◽  
Temperature Model ◽  
Quality Model ◽  
Important Indicator ◽  
The Impact

Abstract Water temperature is an important indicator for biodiversity and ecosystem sustainability. In this study, a simplified equilibrium temperature model was incorporated into the CE-QUAL-W2 (W2) model. This model is easy to implement, needing fewer meteorological variables and no parameter calibration. The model performance was evaluated using observed data from four stations on the Lower Minnesota River. Results show that the simplified equilibrium temperature model performed as well as the original equilibrium temperature model and the term-by-term process model for water temperature predictions with the values of the coefficient of determination (R2), Nash–Sutcliffe Efficiency (NSE), and Percent Error (PE) in the accepted range (R2 = 0.974, NSE = 0.972, PE = 1.377%). The impact of the water temperature on carbonaceous biochemical oxygen demand (CBOD) concentrations under three different water temperature models was evaluated, and results show that the monthly averaged CBOD concentrations of the simplified equilibrium temperature model were almost the same as that of the term-by-term approach. For all the four calibration stations, the simplified equilibrium temperature approach performs better than the other two models for dissolved oxygen simulation (R2 = 0.791, NSE = 0.65, PE = 7.596%), which indicates that the simplified equilibrium temperature model can be a potential tool to simulate water temperature for water quality modelling.

scholarly journals Development of Optimal Management Strategies for the Interception System Using River Water Quality Modeling

2018 ◽  
Vol 175 ◽  
pp. 03024
Author(s):  
Chen-Yao Ma ◽  
Yi-Chu Huang ◽  
Chih-Ming Kao
Keyword(s):  
Water Quality ◽  
Management Strategies ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Water Quality Modeling ◽  
Water Bodies ◽  
Quality Analysis ◽  
Quality Model ◽  
Quality Modeling ◽  
The Impact

This study adopted the water quality model [Water Quality Analysis Simulation Program (WASP)] to simulate and evaluate the impacts of the opening and closure of an interception system at the tributary of Love River on mainstream water quality. The gates were opened respectively for 4, 12, and 24 hours to assess the impact on biochemical oxygen demand (BOD) and ammonia nitrogen (NH3-N) in the water bodies of Love River. The WASP model was used to evaluate the self-purification capacity of the river. According to the results of the model estimation, it takes 5 days for NH3-N and BOD in the water bodies of Love River to return to normal and for the water to restore its original water quality after the closure of the Baozhu Ditch gate. Results of this study can be used as a reference for Love River watershed management, and the WASP modeling can be applied for decision makers to develop appropriate management strategies of the interception system.

scholarly journals Environmental Flow for Sungai Johor Estuary

2018 ◽  
Vol 34 ◽  
pp. 02041
Author(s):  
A.Kadir Adilah ◽  
Yusop Zulkifli ◽  
Z. Noor Zainura ◽  
Baharim N. Bakhiah
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Oxygen Demand ◽  
Correlation Coefficients ◽  
Water Quality Model ◽  
Surface Elevation ◽  
Quality Model ◽  
Quality Models ◽  
Water Quality Models

Sungai Johor estuary is a vital water body in the south of Johor and greatly affects the water quality in the Johor Straits. In the development of the hydrodynamic and water quality models for Sungai Johor estuary, the Environmental Fluid Dynamics Code (EFDC) model was selected. In this application, the EFDC hydrodynamic model was configured to simulate time varying surface elevation, velocity, salinity, and water temperature. The EFDC water quality model was configured to simulate dissolved oxygen (DO), dissolved organic carbon (DOC), chemical oxygen demand (COD), ammoniacal nitrogen (NH3-N), nitrate nitrogen (NO3-N), phosphate (PO4), and Chlorophyll a. The hydrodynamic and water quality model calibration was performed utilizing a set of site specific data acquired in January 2008. The simulated water temperature, salinity and DO showed good and fairly good agreement with observations. The calculated correlation coefficients between computed and observed temperature and salinity were lower compared with the water level. Sensitivity analysis was performed on hydrodynamic and water quality models input parameters to quantify their impact on modeling results such as water surface elevation, salinity and dissolved oxygen concentration. It is anticipated and recommended that the development of this model be continued to synthesize additional field data into the modeling process.

Considering the impact of intermittent discharges when modelling overflows

1998 ◽  
Vol 38 (10) ◽  
pp. 23-30
Author(s):  
Sarah Jubb ◽  
Philip Hulme ◽  
Ian Guymer ◽  
John Martin
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Preliminary Investigation ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Combined Sewer Overflows ◽  
River Hydraulics ◽  
Combined Sewer ◽  
The Impact ◽  
Curve Equation

This paper describes a preliminary investigation that identified factors important in the prediction of river water quality, especially regarding dissolved oxygen (DO) concentration. Intermittent discharges from combined sewer overflows (CSOs) within the sewerage, and overflows at water reclamation works (WRW) cause dynamic conditions with respect to both river hydraulics and water quality. The impact of such discharges has been investigated under both wet and dry weather flow conditions. Data collected from the River Maun, UK, has shown that an immediate, transient oxygen demand exists downstream of an outfall during storm conditions. The presence of a delayed oxygen demand has also been identified. With regard to modelling, initial investigations used a simplified channel and the Streeter-Phelps (1925) dissolved oxygen sag curve equation. Later, a model taking into account hydrodynamic, transport and dispersion processes was used. This suggested that processes other than water phase degradation of organic matter significantly affect the dissolved oxygen concentration downstream of the location of an intermittent discharge. It is proposed that the dynamic rate of reaeration and the sediment oxygen demand should be the focus of further investigation.

scholarly journals Relative Performance of 1-D Versus 3-D Hydrodynamic, Water-Quality Models for Predicting Water Temperature and Oxygen in a Shallow, Eutrophic, Managed Reservoir

Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 88
Author(s):  
Xiamei Man ◽  
Chengwang Lei ◽  
Cayelan C. Carey ◽  
John C. Little
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Water Quality Model ◽  
Relative Performance ◽  
Bubble Plume ◽  
Quality Model ◽  
Quality Models ◽  
Management Interventions ◽  
Water Quality Models ◽  
D Model

Many researchers use one-dimensional (1-D) and three-dimensional (3-D) coupled hydrodynamic and water-quality models to simulate water quality dynamics, but direct comparison of their relative performance is rare. Such comparisons may quantify their relative advantages, which can inform best practices. In this study, we compare two 1-year simulations in a shallow, eutrophic, managed reservoir using a community-developed 1-D model and a 3-D model coupled with the same water-quality model library based on multiple evaluation criteria. In addition, a verified bubble plume model is coupled with the 1-D and 3-D models to simulate the water temperature in four epilimnion mixing periods to further quantify the relative performance of the 1-D and 3-D models. Based on the present investigation, adopting a 1-D water-quality model to calibrate a 3-D model is time-efficient and can produce reasonable results; 3-D models are recommended for simulating thermal stratification and management interventions, whereas 1-D models may be more appropriate for simpler model setups, especially if field data needed for 3-D modeling are lacking.

scholarly journals Simulating Diurnal Variations of Water Temperature and Dissolved Oxygen in Shallow Minnesota Lakes

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1980
Author(s):  
Bushra Tasnim ◽  
Jalil A. Jamily ◽  
Xing Fang ◽  
Yangen Zhou ◽  
Joel S. Hayworth
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Shallow Lakes ◽  
Quality Model ◽  
Lake Water Quality ◽  
Ecological Processes ◽  
Turbulent Diffusion Coefficient ◽  
Hourly Data ◽  
Mean Square Errors

In shallow lakes, water quality is mostly affected by weather conditions and some ecological processes which vary throughout the day. To understand and model diurnal-nocturnal variations, a deterministic, one-dimensional hourly lake water quality model MINLAKE2018 was modified from daily MINLAKE2012, and applied to five shallow lakes in Minnesota to simulate water temperature and dissolved oxygen (DO) over multiple years. A maximum diurnal water temperature variation of 11.40 °C and DO variation of 5.63 mg/L were simulated. The root-mean-square errors (RMSEs) of simulated hourly surface temperatures in five lakes range from 1.19 to 1.95 °C when compared with hourly data over 4–8 years. The RMSEs of temperature and DO simulations from MINLAKE2018 decreased by 17.3% and 18.2%, respectively, and Nash-Sutcliffe efficiency increased by 10.3% and 66.7%, respectively; indicating the hourly model performs better in comparison to daily MINLAKE2012. The hourly model uses variable hourly wind speeds to determine the turbulent diffusion coefficient in the epilimnion and produces more hours of temperature and DO stratification including stratification that lasted several hours on some of the days. The hourly model includes direct solar radiation heating to the bottom sediment that decreases magnitude of heat flux from or to the sediment.

Impact of net pen aquaculture on lake water quality

2003 ◽  
Vol 47 (12) ◽  
pp. 293-300 ◽  
Author(s):  
J. Veenstra ◽  
S. Nolen ◽  
J. Carroll ◽  
C. Ruiz
Keyword(s):  
Water Quality ◽  
Organic Carbon ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Ictalurus Punctatus ◽  
Oxygen Demand ◽  
Total Alkalinity ◽  
Total Hardness ◽  
Army Corps ◽  
Lake Water Quality

A 3-year study was conducted by the U.S. Army Corps of Engineers assessing water quality related impacts of aquaculture of 250,000 channel catfish (Ictalurus punctatus) in floating net pens in the Rock Creek Arm of Lake Texoma, Oklahoma/Texas. Five large nylon nets suspended from a floating framework of galvanized metal anchored in open water 100 m offshore made up the net pens with fish stocking densities varying from 88 to 219 fish/m3. Water quality sampling was conducted biweekly from April to September and monthly from October to March at three locations. On all sampling dates field measurements of water temperature, pH, dissolved oxygen, and conductivity were recorded at 1 m depth intervals and water samples were collected at a depth of 0.5 m and near the bottom of the water column at each site. Sample analyses included: total alkalinity, total hardness, turbidity, chloride, sulfate, orthophosphate, total phosphorus, nitrate-N, nitrite-N, total Kjeldahl nitrogen, total organic carbon, dissolved organic carbon, biochemical oxygen demand, and chlorophyll a. The results showed statistically significant decreases in water temperature and dissolved oxygen and significant increases in field conductivity in surface waters near the net pens relative to other sampling sites. The most dramatic water quality effect observed during the study was decrease in dissolved oxygen levels near the net pens following lake turnover in the second year.

scholarly journals Assessment of Water Quality Profile Using Numerical Modeling Approach in Major Climate Classes of Asia

2018 ◽  
Vol 15 (10) ◽  
pp. 2258 ◽  
Author(s):  
Muhammad Mazhar Iqbal ◽  
Muhammad Shoaib ◽  
Hafiz Umar Farid ◽  
Jung Lyul Lee
Keyword(s):  
Water Quality ◽  
Water Environment ◽  
Oxygen Demand ◽  
Surface Water Quality ◽  
Water Quality Model ◽  
Oxygen Solubility ◽  
Quality Model ◽  
Spatial Profile ◽  
Climatic Regions ◽  
Model Predictions

A river water quality spatial profile has a diverse pattern of variation over different climatic regions. To comprehend this phenomenon, our study evaluated the spatial scale variation of the Water Quality Index (WQI). The study was carried out over four main climatic classes in Asia based on the Koppen-Geiger climate classification system: tropical, temperate, cold, and arid. The one-dimensional surface water quality model, QUAL2Kw was selected and compared for water quality simulations. Calibration and validation were separately performed for the model predictions over different climate classes. The accuracy of the water quality model was assessed using different statistical analyses. The spatial profile of WQI was calculated using model predictions based on dissolved oxygen (DO), biological oxygen demand (BOD), nitrate (NO3), and pH. The results showed that there is a smaller longitudinal variation of WQI in the cold climatic regions than other regions, which does not change the status of WQI. Streams from arid, temperate, and tropical climatic regions show a decreasing trend of DO with respect to the longitudinal profiles of main river flows. Since this study found that each climate zone has the different impact on DO dynamics such as reaeration rate, reoxygenation, and oxygen solubility. The outcomes obtained in this study are expected to provide the impetus for developing a strategy for the viable improvement of the water environment.

scholarly journals Impacts of Leachate Percolation on Ground Water Quality: A Case Study of Dhanbad City

2015 ◽  
Vol 17 (1) ◽  
pp. 162-174 ◽  
Keyword(s):  
Water Quality ◽  
Ground Water ◽  
Oxygen Demand ◽  
Quality Analysis ◽  
Solid Waste Disposal ◽  
Ground Water Quality ◽  
Potential Health ◽  
Groundwater Samples ◽  
High Concentrations ◽  
The Impact

<div> <p>This paper presents an assessment of the impact of uncontrolled and unscientific disposal of MSW on ground water in Dhanbad city, India. In this study, ground water quality around municipal solid waste disposal sites was investigated. Ground water quality analysis was carried out on samples collected at various distances from two disposal sites. The study has revealed that the ground water quality near dumping sites does not conform to the drinking water quality standards as per IS:10500. The impacts of indiscriminate dumping activity on ground water appeared most clearly as high concentrations of total dissolved solids, electrical conductivity, chlorides, chemical oxygen demand, and sulphates. High amount of metals like Na, K, Ca, Mg, Cd, Cu, Ni, Fe, Zn and Mn has also been detected in the groundwater samples near dumping area. Leachate characterization study also reveals high potential for groundwater contamination. Presence of feacal coliform contamination in groundwater samples indicates potential health risk for individuals exposed to this water.&nbsp;</p> </div> <p>&nbsp;</p>

scholarly journals Impact of Partially Treated Wastewater on Downstream Water Quality of Notwane River in Botswana

2018 ◽  
pp. 1-9
Author(s):  
Gilbert K. Gaboutloeloe ◽  
Gugu Molokwe ◽  
Benedict Kayombo
Keyword(s):  
Water Quality ◽  
Pearson Correlation ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Treated Wastewater ◽  
Nitrate N ◽  
River Stretch ◽  
Ph Range ◽  
The Impact

The impact of partially treated wastewater on the water quality of Notwane river stretch in the Gaborone region of Botswana was investigated. Water samples collected at effluent discharge point and three other sampling sites downstream were analyzed for pH, temperature, Biological Oxygen Demand (BOD5), Ammonia-nitrogen (Ammonia-N) and Nitrate-nitrogen (Nitrate-N). Sampling was conducted bi-weekly between February 2013 and April 2013. The ranges of measured parameters were:  pH (7.6-8.5), temperature (22-23ºC), BOD5 (11.2-27.0 mg/l), Ammonia-N (2.4-60.5 mg/l), Nitrate-N (20.6-28.6 mg/l). Analysis of variance, Games-Howel multiple comparisons and Pearson correlation were used to separate variable means. The results signal river non-point pollution due to runoff inflow of organics mainly from land use and domestic waste dumping by nearby dwellings. Temperature, BOD5, and pH range values were all within the Botswana Bureau of Standards (BOBS) limit while the maximum Ammonia-N and Nitrate-N were above BOBS limit by 50.5 mg/l and 6.6 mg/l, respectively. Regulations on indiscriminate waste dumping and discharge standards adherence should be enforced.

scholarly journals The Impact of Floating Net Cage (FNC) on Primary Productivity in Cirata Reservoir Waters

2021 ◽  
pp. 35-42
Author(s):  
Sayyid Arrasyid ◽  
Zahidah Hasan ◽  
Izza Mahdiana Apriliani ◽  
Heti Herawati
Keyword(s):  
Water Quality ◽  
Primary Productivity ◽  
Local Community ◽  
Oxygen Demand ◽  
Quality Standard ◽  
Water Volume ◽  
Physical Parameters ◽  
Reservoir Water ◽  
Net Cages ◽  
The Impact

Cirata Reservoir is one of the three cascade reservoirs fed by the Citarum Watershed with an area of ​​62 km2 (6.200 ha) and has a water volume of 1.900 million m3. The great potential of the waters in the Cirata Reservoir is utilized by the local community as a source of livelihood, namely by conducting aquaculture activities using floating net cages (FNC) in excess. FNC is thought to be a source of waste that reduces reservoir water quality. This research aims to determine the impact of FNC cultivation on primary productivity with different FNC densities at each station. The research was conducted in Cianjur Regency by taking on three stations, namely in the areas of Jangari, Maleber, and Patok Beusi on November 6 - December 8, 2019. The method used in the research was purposive sampling then analyzed in detail and quantitatively. The results show that reservoir waters have an average of physical parameters, namely temperature 32.2-32.6oC, transparency 0.59-0.68 meters, pH 7.1-7.3, carbon dioxide 15.4-16.1 mg / l, Dissolved Oxygen 6.9-7.3 mg / l, Biochemical Oxygen Demand 6.1-7.8 mg / l, nitrate 0.208-0.222 mg / l, ammonia 0.002833-0.003056 mg / l, phosphate 0,165-0,167 mg / l and primary productivity 240,36-277,90 mgC/m3/hour. This shows that the water indicator is still classified as good because it does not exceed the water quality standard.

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