Analytical water quality model for biochemical oxygen demand simulation in River Gomti of Ganga Basin, India

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.

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Sequential calibration of a water quality model using reach-specific parameter estimates

Hydrology Research ◽

10.2166/nh.2017.246 ◽

2017 ◽

Vol 49 (4) ◽

pp. 1042-1055 ◽

Cited By ~ 7

Author(s):

Shushobhit Chaudhary ◽

C. T. Dhanya ◽

Arun Kumar

Keyword(s):

Water Quality ◽

Oxygen Demand ◽

Weighted Average ◽

Sequential Estimation ◽

Water Quality Model ◽

Parameter Estimates ◽

Model Parameters ◽

Quality Model ◽

Study Region ◽

River Stretch

Abstract Calibration is the most critical phase in any water quality modelling process. This study proposes a sequential calibration methodology for any water quality model using reach-specific estimates of model parameters, which would aid in the improved prediction of river water quality characteristics. The proposed methodology accounts for the heterogeneity of river reaches, i.e., diverse characteristics of different reaches on the river stretch. The water quality model, QUAL2K, is coupled with MATLAB, a computing platform, to facilitate sequential estimation of reach-wise model parameters using a grid-based weighted average optimization. The Delhi segment of the Yamuna River is selected as study river stretch. Observations of water quality variables, dissolved oxygen and biochemical oxygen demand are used to calibrate and validate QUAL2K. Desirable performance measures are obtained during the calibration and the validation period. The methodology proves superior to the existing calibration methodologies applied over the study region. The proposed technique also captures the system behaviour effectively, through a systematic, efficient and user-friendly way. The proposed approach is expected to aid decision-makers in formulating better reach-wise management decisions and treatment policies by providing a simpler and efficient way to simulate water quality parameters.

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Critical appraisal of water quality model parameters for an urban city in lower Ganga basin during pre- and post-COVID19 Lockdown in India

Indian Journal of Science and Technology ◽

10.17485/ijst/v14i29.242 ◽

2021 ◽

Vol 14 (29) ◽

pp. 2439-2447

Author(s):

Kamakshi Singh ◽

◽

Ramakar Jha

Keyword(s):

Water Quality ◽

Critical Appraisal ◽

Water Quality Model ◽

Model Parameters ◽

Quality Model ◽

Ganga Basin ◽

Urban City

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Towards benchmarking an in-stream water quality model

Hydrology and Earth System Sciences ◽

10.5194/hess-11-623-2007 ◽

2007 ◽

Vol 11 (1) ◽

pp. 623-633 ◽

Cited By ~ 2

Author(s):

D. B. Boorman

Keyword(s):

Water Quality ◽

Stream Water ◽

A Priori ◽

Oxygen Demand ◽

Water Quality Model ◽

Test Model ◽

Stream Water Quality ◽

Quality Model ◽

Benchmark Model ◽

Model Code

Abstract. A method of model evaluation is presented which utilises a comparison with a benchmark model. The proposed benchmarking concept is one that can be applied to many hydrological models but, in this instance, is implemented in the context of an in-stream water quality model. The benchmark model is defined in such a way that it is easily implemented within the framework of the test model, i.e. the approach relies on two applications of the same model code rather than the application of two separate model codes. This is illustrated using two case studies from the UK, the Rivers Aire and Ouse, with the objective of simulating a water quality classification, general quality assessment (GQA), which is based on dissolved oxygen, biochemical oxygen demand and ammonium. Comparisons between the benchmark and test models are made based on GQA, as well as a step-wise assessment against the components required in its derivation. The benchmarking process yields a great deal of important information about the performance of the test model and raises issues about a priori definition of the assessment criteria.

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Environmental Flow for Sungai Johor Estuary

E3S Web of Conferences ◽

10.1051/e3sconf/20183402041 ◽

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.

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Modeling Biological Oxygen Demand Load Capacity in a Data-Scarce Basin with Important Anthropogenic Interventions

Water ◽

10.3390/w13172379 ◽

2021 ◽

Vol 13 (17) ◽

pp. 2379

Author(s):

Alejandra Zurita ◽

Mauricio Aguayo ◽

Pedro Arriagada ◽

Ricardo Figueroa ◽

María Elisa Díaz ◽

...

Keyword(s):

Water Quality ◽

Carrying Capacity ◽

Stream Water ◽

Oxygen Demand ◽

Biological Oxygen Demand ◽

Water Quality Model ◽

Quality Data ◽

Quality Model ◽

Anthropogenic Pressures ◽

Water Quality Data

Most water bodies are currently used as receptors for pollutants coming mainly from the industrial and domestic sectors. The Biobío river is subjected to multiple anthropogenic pressures such as industrial water supply, drinking water, hydroelectric power generation, agriculture, and the final receptor body of a large amount of industrial and urban waste, pressures that will intensify due to the decrease in water flow as a result of climate change. In this context, organic contamination has been found mainly from sewage discharges and oxidizable waste discharges generated by industrial processes. In this sense, the objective of this research is to determine the Biological Oxygen Demand Loading Capacity (LC) in a basin with a low density of water quality data subjected to strong anthropogenic pressures. To estimate the carrying capacity in a section of the Biobío River, the water quality model River and Stream Water Quality Model- Qual2K version 2.11b8, developed by Chapra, was used. This model solves the Streeter–Phelps equation, proposing an analytical expression to relate the dissolved oxygen (DO) and biochemical oxygen demand (BOD5) variables. These variables were modeled for different critical scenarios of minimum flows in return periods of 5, 50, and 100 years, determining that the studied section of the Biobío river would have a high carrying capacity to not be affected by its organic matter pollution.

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