A novel Hybrid Wavelet-Locally Weighted Linear Regression (W-LWLR) Model for Electrical Conductivity (EC) Prediction in Surface Water

2020 ◽  
Vol 232 ◽  
pp. 103641 ◽  
Author(s):  
Iman Ahmadianfar ◽  
Mehdi Jamei ◽  
Xuefeng Chu
Keyword(s):  
Electrical Conductivity ◽  
Surface Water ◽  
Linear Regression ◽  
Weighted Linear Regression

scholarly journals Electrical Conductivity as a General Predictor of Multiple Parameters in Tigris River Based on Statistical Regression Model

2021 ◽  
Vol 27 (2) ◽  
pp. 73-82
Author(s):  
Omar Anmar Khlaif ◽  
Khalid Adel Abdulrazzaq ◽  
Athraa Hashim Mohammed
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Surface Water ◽  
Linear Regression ◽  
Correlation Coefficients ◽  
Surface Water Quality ◽  
Total Hardness ◽  
Regression Equations ◽  
Statistical Regression ◽  
Prediction Ability

Surface water samples from different locations within Tigris River's boundaries in Baghdad city have been analyzed for drinking purposes. Correlation coefficients among different parameters were determined. An attempt has been made to develop linear regression equations to predict the concentration of water quality constituents having significant correlation coefficients with electrical conductivity (EC). This study aims to find five regression models produced and validated using electrical conductivity as a predictor to predict total hardness (TH), calcium (Ca), chloride (Cl), sulfate (SO4), and total dissolved solids (TDS). The five models showed good/excellent prediction ability of the parameters mentioned above, which is a very good startup to establish a rule of thumb in the laboratories to compare between observations. The importance of linear regression equations in predicting surface water quality parameters is a method that can be applied to any other location.  

scholarly journals An evaluation of water quality at Sandhill Wetland: implications for reclaiming wetlands above soft tailings deposits in northern Alberta, Canada

2021 ◽  
Author(s):  
Jeremy A. Hartsock ◽  
Jessica Piercey ◽  
Melissa K. House ◽  
Dale H. Vitt
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Surface Water ◽  
Water Chemistry ◽  
Water Quality Monitoring ◽  
Total Alkalinity ◽  
Near Surface ◽  
Water Quality Guidelines ◽  
Quality Guidelines ◽  
Annual Water

AbstractThe experimental Sandhill Wetland is the first permanent reclamation of a composite tailings deposit, and annual water quality monitoring is of specific interest for evaluating and predicting long-term reclamation performance. Here, we present water chemistry monitoring data obtained from Sandhill Wetland (years 2009–2019) and compare results to twelve natural reference wetlands and to environmental quality guidelines for Alberta surface waters. By comparing water quality at Sandhill Wetland and natural sites to established guidelines, we can begin to document the natural background water quality of wetlands in the region and examine if guideline exceedances are seen in natural undisturbed environments, or appear only at active reclamation sites. At Sandhill Wetland the dominant ions in near-surface water were bicarbonate, sulfate, chloride, sodium, calcium, and magnesium. Since the first growing season concentrations for these ions have increased annually, causing concurrent increases in electrical conductivity. In year 2019, water chemistry at Sandhill Wetland was most comparable to regional saline fens, systems that exhibit elevated electrical conductivity and high sodicity. Near-surface water at Sandhill Wetland exceeded water quality guidelines for three substances/properties (dissolved chloride, iron, and total alkalinity) in the most recent year of monitoring. The saline fen natural sites also exceeded water quality guidelines for the same chemical substances/properties, suggesting guideline exceedances are a norm for some natural wetland site types in the region. Of note, in each year of monitoring at Sandhill Wetland, dissolved organic compounds evaluated in sub- and near-surface water were below detection limits.

Analysing surface water-groundwater interactions on selected sites of the River Moselle: Identifying transport processes along an important inland waterway in Germany

2021 ◽  
Author(s):  
Simon Mischel ◽  
Michael Engel ◽  
Sabrina Quanz ◽  
Dirk Radny ◽  
Axel Schmidt ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Surface Water ◽  
Transport Processes ◽  
Main Stream ◽  
Flow Conditions ◽  
Inland Waterway ◽  
Trace Compounds ◽  
Organic Trace Compounds ◽  
Longitudinal Sampling ◽  
Organic Trace

<p>Hydraulic engineering structures like locks affect the natural hydraulic conditions and have a relevant impact on surface water – groundwater interactions due to enlarging the hydraulic gradient. For this, these sites are excellent areas to study associated flow paths, mass transport and their spatial and temporal variability in higher detail. However, no large-scale study at an inland waterway is available in Germany until now.</p><p>Our work aims to close this gap by applying a multiparameter approach for analyzing surface water-groundwater-interactions by using pH, electrical conductivity, major ions in combination with various other tracers like stable water isotopes, 222-Rn, and tritium. In this context, we also investigate the usability of organic trace compounds and their associated transformation products as potential new tracers.</p><p>The main study approach is based on the hypothesis that i) gaining stream sections show relatively high 222-Rn concentrations originating from discharging groundwater and ii) losing stream sections which are characterized by low 222-Rn concentrations as well as lower tritium and organic trace compounds inventories compared to unaffected areas.</p><p>During different flow-scenarios of the river Moselle, we test these hypotheses by means of a high-resolution longitudinal sampling at 2 km intervals of the main stream (along 242 km) and its major tributaries in combination with groundwater sampling at numerous wells.</p><p>Here, we present the first results of the longitudinal sampling campaign of the river Moselle in October 2020, which took place during intermediate flow conditions (Q=200 m³/s). We used on-site and in-situ 222-Rn measurements and electrical conductivity as a tracer to immediately identify zones along the Moselle with increased groundwater inflow.</p><p>With the use of these tracers, we will deepen the conceptual process understanding of surface water – groundwater interactions occurring at larger streams and during different flow conditions, which may lead to a general river characterization of losing and gaining stream reaches. Moreover, understanding the sources of water compounds and the processes involved during transportation and transformation is crucial for maintaining a good quality of the water body, which is key for proper water management. The findings obtained in the region of the Moselle river might be further transferred to other waterways and support decision making.</p>

Online estimation of VFA, alkalinity and bicarbonate concentrations by electrical conductivity measurement during anaerobic fermentation

2012 ◽  
Vol 65 (7) ◽  
pp. 1281-1289 ◽  
Author(s):  
Cesar-Arturo Aceves-Lara ◽  
Eric Latrille ◽  
T. Conte ◽  
Jean-Philippe Steyer
Keyword(s):  
Electrical Conductivity ◽  
Hydrogen Production ◽  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Anaerobic Fermentation ◽  
Simple Linear Regression ◽  
Conductivity Measurements ◽  
Bicarbonate Concentration ◽  
On Line

This paper describes the use of electrical conductivity for measurement of volatile fatty acids (VFA), alkalinity and bicarbonate concentrations, during the anaerobic fermentation process. Two anaerobic continuous processes were studied: the first was a laboratory reactor for hydrogen production from molasses and the second was a pilot process for anaerobic digestion (AD) of vinasses producing methane. In the hydrogen production process, the total VFA concentration, but not bicarbonate concentration, was well estimated from the on-line electrical conductivity measurements with a simple linear regression model. In the methane production process, the bicarbonate concentration and the VFA concentration were well estimated from the simultaneous on-line measurements of pH and electrical conductivity by means of non-linear regression with neural network models. Moreover, the total alkalinity concentration was well estimated from electrical conductivity measurements with a simple linear regression model. This demonstrates the use of electrical conductivity for monitoring the AD processes.

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.

scholarly journals Some physicochemical parameters in the surface water of mini Whuo Stream in Port Harcourt, Rivers State, Nigeria

2021 ◽  
Vol 9 (3) ◽  
pp. 039-047
Author(s):  
Edori ES ◽  
Iyama WA ◽  
Awari JO
Keyword(s):  
Electrical Conductivity ◽  
Surface Water ◽  
Physicochemical Properties ◽  
Human Activities ◽  
Physicochemical Parameters ◽  
Present Situation ◽  
Total Alkalinity ◽  
Acceptable Limit ◽  
Port Harcourt ◽  
Rivers State

The levels of physicochemical properties of Mini Whuo Stream in Port Harcourt, Rivers State, Nigeria was evaluated. The physicochemical parameters were analyzed using standard conventional procedures. The average values recorded for the physicochemical parameters during the months of investigation were in the range; temperature; 30.00±0.42-30.26±0.83oC, with all-round mean of 30.14±0.47oC, pH; 6.22±0.33-6.42±0.25 (6.29±0.29), electrical conductivity; 146.01±74.04-147.26±75.13µS/cm (146.58±74.69 µS/cm), total alkalinity; 61.63±6.37-62.20±6.41mg/L (61.91±6.41 mg/L), sulphates; 109.67±51.34-110.67±51.88mg/L (110.22±51.81 mg/L), nitrates; 12.20±2.38-12.60±2.86mg/L (12.31±2.65 mg/L), turbidity; 49.32±1.49-50.18±2.02 NTU(49.83±1.55 NTU), TDS; 74.20±36.43-75.61±37.50 mg/L (75.00±36.81 mg/L), TSS; 27.14±2.12-28.37±0.78mg/L (27.64±1.89 mg/L), chlorides; 15.17±2.90-15.66±2.70mg/L (15.34±2.65 mg/L) and salinity; 24.36±4.83-24.82±4.97mg/L (24.66±4.78 mg/L). The evaluation of the physicochemical parameters showed that the Mini Whuo Stream has been contaminated due to human activities within the stream and therefore adequate measures should be taken to forestall the present situation of the stream in order to mitigate any possible increase in deterioration of the studied physicochemical parameters in the stream beyond acceptable limit.

scholarly journals Is it possible to estimate longevity through the analyses used to measure the initial physiological potential in soybean seeds?

2021 ◽  
Vol 43 ◽  
Author(s):  
Thiago Barbosa Batista ◽  
Samara Moreira Perissato ◽  
Carlos Henrique Queiroz Rego ◽  
Gustavo Roberto Fonseca de Oliveira ◽  
Fernando Augusto Henning ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Linear Regression ◽  
Soybean Seed ◽  
Accelerated Aging ◽  
Storage Period ◽  
High Potential ◽  
Seed Longevity ◽  
Soybean Seeds ◽  
Radicle Protrusion ◽  
Over Time

Abstract: The analysis of longevity can support decisions about the length of seed lot storage until commercialization, since this characteristic implies the maintenance of viability over time. Seed longevity is analyzed by the p50 test, which expresses the time to lose 50% of the initial viability. Seeds with high vigor and germination have greater physiological potential and, thus, a greater capacity to maintain quality throughout the storage period. However, there has been little research on the correlations between the analysis of p50 (longevity) and the tests used to measure physiological potential (germination and vigor) of lots, which can be used as a tool to make inferences about longevity using the most traditional tests. Thus, the objective of this study was to investigate which tests used to measure the potential of lots can estimate p50. To this end, germination and vigor were evaluated using traditional tests while longevity was assessed in eight soybean seed lots. Correlations and linear regression were tested for the traditional variables versus p50. It was found that the use of accelerated aging, electrical conductivity, and time to 50% radicle protrusion has high potential to estimate longevity as measured by p50.

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