A New Online Computer Program (Bidasys) for Ordinary and Uncertainty Weighted Least-Squares Linear Regressions: Case Studies From Food Chemistry

Rosales, M.

doi:10.24275/uam/izt/dcbi/revmexingquim/2018v17n2/rosales

Cited by 16 publications

(5 citation statements)

References 26 publications

(58 reference statements)

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“…The grouping (for shallow and deep groundwater) and number of discordant values observed, the R, and R 2 values are also presented (Tables 2 and 3). A better fit was obtained using UWLR with lower values of uncertainties compared to those for OLR, which was consistent with reports by Rosales-Rivera et al [38]. UWLR showed an improved local meteoric water line (LMWL) to be δ 2 H = 5.0918(±0.2647) δ 18 O − 10.5123(±2.4577), with R 2 = 0.9003-values within the brackets represent uncertainty values at the strict confidence level of 99% ( Figure 5).…”

Section: Isotopic Composition Of Watersupporting

confidence: 91%

“…The BiDASys (bivariate data analysis system) software [38] was used to apply ordinary and uncertainty weighted least-squares linear regression models (OLR and UWLR). Rosales Rivera et al [38] and Verma [39] reported that the UWLR should be considered as a better alternative because the use of uncertainty has a probability connotation with a strict confidence level of 99%, which was used in the present study. The OLR and UWLR were used to estimate the new LMWL, and several regressions with the different sampled sources of water.…”

Section: Bivariate Data Analysismentioning

confidence: 99%

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Integration of Isotopic (2H and 18O) and Geophysical Applications to Define a Groundwater Conceptual Model in Semiarid Regions

Pacheco-Guerrero

Gonzalez-Trinidad

Júnez-Ferreira

et al. 2019

Water

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One-third of the global population depends on groundwater for drinking, which is an even larger proportion for arid regions. The integration of isotopic and geophysical applications has been very useful in understanding the process of groundwater recharge. The aim of this study is to define a conceptual model that describes groundwater functions within an aquifer located in a semi-arid region by identifying recharge patterns based on the isotopic characteristics of: Rainfall, surface water, shallow and deep groundwater, and incorporating regional geophysical data. We demonstrated that rainfall was affected by sub-cloud evaporation and altitude. Shallow and deep modern groundwater samples were clustered and exhibited similar evolution from rainfall. However, different groups recharged from different precipitation sources compared to the local one. In the current study, we analyzed the isotopic evolution of deep groundwater over a 10-year period, which was mainly affected by the incorporation of different flows with different isotopic signatures and the hydrodynamics of the area. We performed two geoelectrical sections in the study area to improve the understanding of the hydrogeological setting and water movement patterns. The new conceptual model should help stakeholders in the context of water management policies for the study area.

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Section: Isotopic Composition Of Watersupporting

confidence: 91%

Section: Bivariate Data Analysismentioning

confidence: 99%

Integration of Isotopic (2H and 18O) and Geophysical Applications to Define a Groundwater Conceptual Model in Semiarid Regions

Pacheco-Guerrero

Gonzalez-Trinidad

Júnez-Ferreira

et al. 2019

Water

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“…The UWLR should is considered as a better alternative because the use of uncertainty has a probability connotation with a strict confidence level of 99%, which was used in the present study. The regressions were acquired correlating the average monthly values of temperature and rainfall (obtained by IDW) and the average values of each VI classification [48,49].…”

Section: Bivariate Analysismentioning

confidence: 99%

Spatio-Temporal Response of Vegetation Indices to Rainfall and Temperature in A Semiarid Region

et al. 2020

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In this research, vegetation indices (VIs) were analyzed as indicators of the spatio-temporal variation of vegetation in a semi-arid region. For a better understanding of this dynamic, interactions between vegetation and climate should be studied more widely. To this end, the following methodology was proposed: (1) acquire the NDVI, EVI, SAVI, MSAVI, and NDMI by classification of vegetation and land cover categories in a monthly period from 2014 to 2018; (2) perform a geostatistical analysis of rainfall and temperature; and (3) assess the application of ordinary and uncertainty least squares linear regression models to experimental data from the response of vegetation indices to climatic variables through the BiDASys (bivariate data analysis system) program. The proposed methodology was tested in a semi-arid region of Zacatecas, Mexico. It was found that besides the high values in the indices that indicate good health, the climatic variables that have an impact on the study area should be considered given the close relationship with the vegetation. A better correlation of the NDMI and EVI with rainfall and temperature was found, and similarly, the relationship between VIs and climatic factors showed a general time lag effect. This methodology can be considered in management and conservation plans of natural ecosystems, in the context of climate change and sustainable development policies.

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“…Five recursive discordancy tests with the highest detection power and with the lowest skewness and masking effects were applied to detect possible discordant outliers in the studentized residuals from the bivariate samples. OLR and UWLR were used to estimate the correlation between arsenic and other parameters in the different flow systems determined [53].…”

Section: Discussionmentioning

confidence: 99%

“…The BiDASys software was used to process the data and find correlations between different parameters [53]. An uncertainty weighted least-squares linear regression (UWLR) for arsenic and other parameters was conducted (Figures 13-15).…”

Section: Bivariate Data Analysismentioning

confidence: 99%

Evaluation of Groundwater Quality for Human Consumption and Irrigation in Relation to Arsenic Concentration in Flow Systems in a Semi-Arid Mexican Region

Ortiz-Letechipia

Gonzalez-Trinidad

Júnez-Ferreira

et al. 2021

IJERPH

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The supply of drinking water to the population is an important challenge facing humanity, since both surface and underground sources present a great variability of water storage with respect to space and time. This problem is further aggravated in arid and semi-arid areas where rainfall is low and torrential, which makes groundwater the main source of supply; therefore, it is necessary to carry out studies that allow evaluating the evolution of the quantity and quality of water. This study addresses the behavior of groundwater in a semi-arid region, considering the theory of flow systems to identify movement as well as water quality, es determined by a water quality index (WQI), calculated considering arsenic and fluorine. In addition, a quality irrigation classification is used, employing the norms in accordance with international standards and the Mexican Norm, which allows for a comparison. Local, regional, intermediate and mixed flow systems are identified, and the evolution of cations and anions in addition to temperature is examined. It is observed that the drinking water quality index classifies them as excellent in most of the monitored wells (<50), but with a negative evolution. Regarding irrigation, most of the water samples are classified without restriction for the establishment of any type II crop (C2S1) and with restrictions for horticultural crops. It is observed that arsenic had values between 0.49 and 61.40 (µg/L) in 2005, while in 2015 they were between 0.10 and 241.30 (µg/L). In addition, fluoride presented values between 0.00 and 2.6 (mg/L) in 2005, while in 2015 they were between 0.28 and 5.40 (mg/L). The correlations between arsenic and fluorine are noted as well as WQI and SAR. A finding in this research was to include arsenic and fluorine in the calculation of the WQI allowing a better interpretation of the quality of water for both human consumption and for agricultural use to based on this make the best decision to control any harmful effects for the population, in addition to identifying the appropriate purification treatment required to control pollutants. It is concluded that arsenic is an element of utmost importance when considering water quality, so it is necessary to examine its evolution and continue to monitor its levels constantly.

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A New Online Computer Program (Bidasys) for Ordinary and Uncertainty Weighted Least-Squares Linear Regressions: Case Studies From Food Chemistry

Abstract: Modelado de la biodegradación en biorreactores de lodos de hidrocarburos totales del petróleo intemperizados en suelos y sedimentos (Biodegradation modeling of sludge bioreactors of total petroleum hydrocarbons weathering in soil and sediments)

Cited by 16 publications

References 26 publications

Integration of Isotopic (2H and 18O) and Geophysical Applications to Define a Groundwater Conceptual Model in Semiarid Regions

Integration of Isotopic (2H and 18O) and Geophysical Applications to Define a Groundwater Conceptual Model in Semiarid Regions

Spatio-Temporal Response of Vegetation Indices to Rainfall and Temperature in A Semiarid Region

Evaluation of Groundwater Quality for Human Consumption and Irrigation in Relation to Arsenic Concentration in Flow Systems in a Semi-Arid Mexican Region

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