Recursive water quality forecasting models for urban catchments

1987 ◽  
Vol 14 (2) ◽  
pp. 221-229
Author(s):  
Gilles G. Patry
Keyword(s):  
Water Quality ◽  
Real Time ◽  
Moving Average ◽  
Integrated Control ◽  
Oxygen Demand ◽  
Lead Times ◽  
Urban Water Quality ◽  
Combined Sewer ◽  
Forecast Models ◽  
Urban Catchments

Urban water quality forecast models for use in real-time integrated control of combined sewer systems are developed and applied to a small combined sewer system in Hamilton, Ontario. Water quality forecasts for lead times ranging from 5 to 60 min are provided for both suspended solids and chemical oxygen demand. Two modelling approaches are examined: (a) a statistical approach based on the formulation of autoregressive moving-average models with exogenous inputs and (b) a two-stage deterministic/stochastic model based on the first-order surface pollutant washoff model. While both groups of model yield comparable forecasts in terms of the mean absolute percent error in water quality forecasts, statistically based models were found to provide definite operational advantages. Key words: adaptative modelling, real-time forecasting, statistical model, stochastic system, urban hydrology, water quality modelling.

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.

Developing a public information and engagement portal of urban waterways with real-time monitoring and modeling

2011 ◽  
Vol 63 (2) ◽  
pp. 248-254 ◽  
Author(s):  
T. A. Cochrane ◽  
D. Wicke ◽  
A. O’Sullivan
Keyword(s):  
Water Quality ◽  
Real Time ◽  
Monitoring System ◽  
Public Awareness ◽  
Mesh Network ◽  
Web Portal ◽  
Alert System ◽  
Urban Waterways ◽  
Effective Manner ◽  
Urban Catchments

Waterways can contribute to the beauty and livelihood of urban areas, but maintaining their hydro-ecosystem health is challenging because they are often recipients of contaminated water from stormwater runoff and other discharges. Public awareness of local waterways’ health and community impacts to these waterways is usually poor due to of lack of easily available information. To improve community awareness of water quality in urban waterways in New Zealand, a web portal was developed featuring a real-time waterways monitoring system, a public forum, historical data, interactive maps, contaminant modelling scenarios, mitigation recommendations, and a prototype contamination alert system. The monitoring system featured in the web portal is unique in the use of wireless mesh network technology, direct integration with online modelling, and a clear target of public engagement. The modelling aims to show the origin of contaminants within the local catchment and to help the community prioritize mitigation efforts to improve water quality in local waterways. The contamination alert system aims to keep managers and community members better informed and to provide a more timely response opportunity to avert any unplanned or accidental contamination of the waterways. Preliminary feedback has been positive and is being supported by local and regional authorities. The system was developed in a cost-effective manner providing a community focussed solution for quantifying and mitigating key contaminants in urban catchments and is applicable and transferable to other cities with similar stormwater challenges.

scholarly journals The Estimation of Chemical Oxygen Demand of Erhai Lake Basin and Its Links with DOM Fluorescent Components Using Machine Learning

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3629
Author(s):  
Yuquan Zhao ◽  
Jian Shen ◽  
Jimeng Feng ◽  
Zhitong Sun ◽  
Tianyang Sun ◽  
...  
Keyword(s):  
Machine Learning ◽  
Water Quality ◽  
Chemical Oxygen Demand ◽  
Real Time ◽  
Oxygen Demand ◽  
Organic Pollution ◽  
Lake Basin ◽  
Erhai Lake ◽  
Real Time Monitoring ◽  
The Relationship

Water quality estimation tools based on real-time monitoring are essential for the effective management of organic pollution in watersheds. This study aims to monitor changes in the levels of chemical oxygen demand (COD, CODMn) and dissolved organic matter (DOM) in Erhai Lake Basin, exploring their relationships and the ability of DOM to estimate COD and CODMn. Excitation emission matrix–parallel factor analysis (EEM–PARAFAC) of DOM identified protein-like component (C1) and humic-like components (C2, C3, C4). Combined with random forest (RF), maximum fluorescence intensity (Fmax) values of components were selected as estimation parameters to establish models. Results proved that the COD of rivers was more sensitive to the reduction in C1 and C2, while CODMn was more sensitive to C4. The DOM of Erhai Lake thrived by internal sources, and the relationship between COD, CODMn, and DOM of Erhai Lake was more complicated than rivers (inflow rivers of Erhai Lake). Models for rivers achieved good estimations, and by adding dissolved oxygen and water temperature, the estimation ability of COD models for Erhai Lake was significantly improved. This study demonstrates that DOM-based machine learning can be used as an alternative tool for real-time monitoring of organic pollution and deepening the understanding of the relationship between COD, CODMn, and DOM, and provide a scientific basis for water quality management.

scholarly journals The Influence of Concrete and Urban Water Quality On The Growth of An Invasive Weed (Salix Spp.) in One of Australia’s Most Endangered Aquatic Environments.

2021 ◽  
Author(s):  
Katherine Purdy ◽  
Jason K Reynolds ◽  
Ian Alexander Wright
Keyword(s):  
Water Quality ◽  
Urban Water ◽  
Invasive Weeds ◽  
Soil Geochemistry ◽  
Invasive Weed ◽  
Blue Mountains ◽  
Urban Water Quality ◽  
Urban Catchments ◽  
Concrete Materials ◽  
Water Treatments

Abstract Riparian vegetation along urban streams and wetlands is frequently dominated by invasive weeds. Elevated nitrogen and phosphorous in urban waters and soils are well-known to encourage invasive urban weeds, but this research demonstrates that other urban geochemical contaminants may also be influential. Previous studies have demonstrated that the dissolution of urban concrete is a poorly recognised source of modified water and soil geochemistry, which may enhance the growth of some invasive weeds. This study investigated the relationship between urban water quality and the growth of an invasive urban riparian weed, willow (Salix spp.) to examine the contribution of concrete materials. The study used water from a wetland in the Greater Blue Mountains World Heritage Area. These wetlands have a unique biodiversity but are fragile and susceptible to degradation from human activity. Many are in urban catchments and are frequently dominated by invasive weeds, including Salix spp. In this study, willow cuttings were grown in a laboratory using four water treatments: pristine, urban, and pristine water exposed to two different concrete materials. The urban and concrete water treatments had higher pH, salinity, calcium, potassium, and higher concentration of several metals and were associated with increased growth of Salix spp. We suggest that the modification of urban water and riparian soil chemistry by urban concrete materials may contribute to the success of invasive species in urban wetlands and riparian zones. Some metals (barium, strontium) were present in urban water and in pristine water exposed to concrete and bioaccumulated in plant tissue.

A real time forecast of the electron fluxes measured by GOES 16

2021 ◽  
Author(s):  
Richard Boynton ◽  
Michael Balikhin ◽  
Hualiang Wei
Keyword(s):  
Solar Wind ◽  
Real Time ◽  
Moving Average ◽  
Autoregressive Moving Average ◽  
Time System ◽  
Real Time System ◽  
Forecast Models ◽  
Forecasting System ◽  
Solar Wind Parameters ◽  
Nonlinear Autoregressive

<p>A real time system is developed to forecast the electron fluxes measured by GOES R spacecraft. Forecast models are developed using the system identification/machine learning methodology based on Nonlinear Autoregressive Moving Average exogenous (NARMAX) models. NARMAX algorithms use past input-output data to automatically deduce a model of the system. Here, the solar wind parameters are used as inputs and the electron fluxes measured by GOES 16 are used as the outputs to deduce the models. The models are then implemented in a real time forecasting system. The forecasting system uses real time solar wind data from ACE, DSCOVR, and ENLIL, which are then processed into the correct format for the NARMAX models to provide a forecast of the electron fluxes at geostationary orbit. </p>

Impact of rainfall temporal resolution on urban water quality modelling performance and uncertainties

2013 ◽  
Vol 68 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Bastian Johann Manz ◽  
Juan Pablo Rodríguez ◽  
Čedo Maksimović ◽  
Neil McIntyre
Keyword(s):  
Water Quality ◽  
Temporal Resolution ◽  
Rainfall Variability ◽  
Water Quality Model ◽  
Urban Water ◽  
Water Quality Modelling ◽  
Quality Model ◽  
Urban Water Quality ◽  
Urban Catchments ◽  
The Impact

A key control on the response of an urban drainage model is how well the observed rainfall records represent the real rainfall variability. Particularly in urban catchments with fast response flow regimes, the selection of temporal resolution in rainfall data collection is critical. Furthermore, the impact of the rainfall variability on the model response is amplified for water quality estimates, as uncertainty in rainfall intensity affects both the rainfall-runoff and pollutant wash-off sub-models, thus compounding uncertainties. A modelling study was designed to investigate the impact of altering rainfall temporal resolution on the magnitude and behaviour of uncertainties associated with the hydrological modelling compared with water quality modelling. The case study was an 85-ha combined sewer sub-catchment in Bogotá (Colombia). Water quality estimates showed greater sensitivity to the inter-event variability in rainfall hyetograph characteristics than to changes in the rainfall input temporal resolution. Overall, uncertainties from the water quality model were two- to five-fold those of the hydrological model. However, owing to the intrinsic scarcity of observations in urban water quality modelling, total model output uncertainties, especially from the water quality model, were too large to make recommendations for particular model structures or parameter values with respect to rainfall temporal resolution.

scholarly journals Impact of roof surface runoff on urban water quality

2012 ◽  
Vol 66 (7) ◽  
pp. 1527-1533 ◽  
Author(s):  
P. Egodawatta ◽  
N. S. Miguntanna ◽  
A. Goonetilleke
Keyword(s):  
Water Quality ◽  
Stormwater Runoff ◽  
Urban Water ◽  
Urban Stormwater ◽  
Urban Water Quality ◽  
Impervious Area ◽  
Road Surfaces ◽  
Urban Catchments ◽  
Urban Stormwater Runoff

The pollutant impacts of urban stormwater runoff on receiving waters are well documented in research literature. However, it is road surfaces that are commonly identified as the significant pollutant source. This paper presents the outcomes of an extensive program of research into the role of roof surfaces in urban water quality with particular focus on solids, nutrients and organic carbon. The outcomes confirmed that roof surfaces play an important role in influencing the pollutant characteristics of urban stormwater runoff. Pollutant build-up and wash-off characteristics for roads and roof surfaces were found to be appreciably different. The pollutant wash-off characteristics exhibited by roof surfaces show that it influences the first flush phenomenon more significantly than road surfaces. In most urban catchments, as roof surfaces constitute a higher fraction of impervious area compared with road surfaces, it is important that the pollutant generation role of roof surfaces is specifically taken into consideration in stormwater quality mitigation strategies.

scholarly journals EmiStatR: A Simplified and Scalable Urban Water Quality Model for Simulation of Combined Sewer Overflows

Water ◽  
2018 ◽  
Vol 10 (6) ◽  
pp. 782 ◽  
Author(s):  
Jairo Torres-Matallana ◽  
Ulrich Leopold ◽  
Kai Klepiszewski ◽  
Gerard Heuvelink
Keyword(s):  
Water Quality ◽  
Water Quality Model ◽  
Urban Water ◽  
Combined Sewer Overflows ◽  
Quality Model ◽  
Urban Water Quality ◽  
Combined Sewer ◽  
Sewer Overflows

IDENTIFICATION AND APPLICATION OF A DYNAMIC MODEL FOR OPERATIONAL MANAGEMENT OF WATER QUALITY

1994 ◽  
Vol 30 (2) ◽  
pp. 31-41 ◽  
Author(s):  
M. B. Beck ◽  
A. Reda
Keyword(s):  
Water Quality ◽  
Real Time ◽  
Stream Water ◽  
Oxygen Demand ◽  
Integrated Approach ◽  
State Variables ◽  
Real Time Control ◽  
Stream Water Quality ◽  
Good Test ◽  
Time Control

The paper summarises recent progress in a long-term programme of research on an integrated approach to the management, md real-time control of water quality in river basins. The focus of this progrmnme is the development, md application of simulation models for the dynamic behaviour of wastewater treatment plants, and in-stream water quality. The model for the latter is based on a multiple continuously stirred tank reactor (MCSTR) approximation of fluid and solute propagation along a river system. Results are presented for the identification (calibration) of this model with reference to field observations from the River Cam in eastern England. These results illustrate the benefits of significant changes to the hydraulic basis of the model (relative to earlier applications). They also provide a good test of the model's capabilities in respect of solute transport, md the biochemical interactions among the five state variables of water quality, i.e., biochemical oxygen demand, dissolved oxygen, ammonium-N, nitrate- N, and chlorophyll-a. The model is applied to the assessment of management and real-time control strategies for attenuating the adverse effects on stream water quality of storm sewage surges passing from the sewer network and through the wastewater plant. The assessment includes the coordinated manipulation of in-stream hydraulic structures to improve controlled performance.

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