scholarly journals Stochastic hydro-economic model for groundwater quality management using Bayesian networks

2013 ◽  
Vol 67 (3) ◽  
pp. 579-586 ◽  
Author(s):  
José-Luis Molina ◽  
Manuel Pulido-Velázquez ◽  
Carlos Llopis-Albert ◽  
Salvador Peña-Haro
Keyword(s):  
Bayesian Networks ◽  
Groundwater Quality ◽  
Socioeconomic Development ◽  
Groundwater Resources ◽  
Economic Modelling ◽  
Normative Development ◽  
Streamflow Depletion ◽  
Different Sources ◽  
Groundwater Body ◽  
Flow And Mass Transport

A strong normative development in Europe, including the Nitrate Directive (1991) and the Water Framework Directive (WFD) (2000), has been promulgated. The WFD states that all water bodies have to reach a good quantitative and chemical status by 2015. It is necessary to consider different objectives, often in conflict, for tackling a suitable assessment of the impacts generated by water policies aimed to reduce nitrate pollution in groundwater. For that, an annual lumped probabilistic model based on Bayesian networks (BNs) has been designed for hydro-economic modelling of groundwater quality control under uncertain conditions. The information introduced in the BN model comes from different sources such as previous groundwater flow and mass transport simulations, hydro-economic models, stakeholders and expert opinion, etc. The methodology was applied to the El Salobral–Los Llanos aquifer unit within the ‘Easter Mancha’ groundwater body, which is one of the largest aquifers in Spain (7,400 km2), included in the Júcar River Basin. Over the past 30 years, socioeconomic development within the region has been mainly depending on intensive use of groundwater resources for irrigating crops. This has provoked a continuous groundwater level fall in the last two decades and significant streamflow depletion in the connected Júcar River. This BN model has proved to be a robust Decision Support System for helping water managers in the decision making process.

A GIS-based assessment of spatial groundwater quality for drinking purposes in Asmara City, Eritrea

2021 ◽  
Author(s):  
Kabral Mogos Asghede ◽  
Dawit Berhane Hagos
Keyword(s):  
Groundwater Quality ◽  
Potable Water ◽  
Critical Level ◽  
Groundwater Resources ◽  
Total Dissolved Solids ◽  
Total Hardness ◽  
Analysis Framework ◽  
Alternative Source ◽  
Drinking Purposes ◽  
Supply Problem

<p><strong>Abstract</strong>: Presently the water-supply problem in the Asmara area has reached to a critical level. Using a GIS-based method this study identifies the spatial variability of the groundwater quality in the Asmara Area which could be an alternative source. The results show that, the Total Dissolved Solids (TDS), Total Hardness (TH), Chloride (Cl<sup>-</sup>), Nitrates (NO<sub>3</sub><sup>-</sup>), Calcium (Ca), Magnesium (Mg), Sulphate (SO<sub>4</sub>) and pH are 791.71, 569.12, 124.41, 64.46, 155.60, 46.64, 159.26 and 7.72 mg/L, respectively. Moreover, the zone map of the developed groundwater quality shows that the potable water without treatment covers about 35%, and the potable water in the absence of better alternate sources covers about 58% of the total area. The remaining, 7.04% of the total, falls under non-potable groundwater quality. The verification of the spatialanalysis demonstrates that the framework is the first one in Eritrea and could be used as a potential prediction for the assessment of the spatial groundwater quality in the countries with further verification results. Hence, the delineation of groundwater quality zones and establishment of a GIS-based database will easily help the decision makersto monitor and plan the utilization of the groundwater resources in the study area.</p><p><strong>Keywords: </strong>Groundwater quality; physicochemical parameters; GIS spatial analysis; framework</p>

Spatial distribution of physico-chemical parameters for groundwater quality evaluation in a part of Satluj River Basin, India

2019 ◽  
Vol 19 (5) ◽  
pp. 1480-1490 ◽  
Author(s):  
Akshay Kumar Chaudhry ◽  
Kamal Kumar ◽  
Mohammad Afaq Alam
Keyword(s):  
Spatial Distribution ◽  
Groundwater Quality ◽  
Spatial Dependence ◽  
Groundwater Resources ◽  
Quality Parameters ◽  
Northern Region ◽  
Total Hardness ◽  
Data Set ◽  
Distribution Maps ◽  
Physico Chemical

Abstract The rising population, contamination and mismanagement of groundwater worldwide require sustainable management techniques and strategies to prevent misuse of groundwater resources especially in the semi-arid regions of the world. The aim of the present study is to assess the distribution of contaminants in groundwater at a spatial level by using a geostatistical method, namely ordinary kriging. For this, a physico-chemical parameter data set at 14 sampling locations for a period over 25 years was assessed. Three semi-variogram models, namely exponential, Gaussian and spherical, fitted well for the data set and were cross-validated using predictive statistics. Based on nugget/sill ratio, which characterizes the overall spatial dependence of water quality parameters, it was observed that, apart from nitrate, all the other parameters showed moderate to weak spatial dependence (i.e. total hardness), indicating significant influence of urbanization, fertilization and industrialization. Spatial distribution maps of all the parameters were generated. Concentration of most of the parameters reported high values in the northern region, while silicon dioxide and potassium recorded high values in the southern and central regions of the study area respectively. The study highlighted the depleting groundwater resources in various regions of the study area, indicating that the groundwater quality is in a declining state.

scholarly journals Hydrogeochemical Characteristics and Groundwater Quality Evaluation Based on Multivariate Statistical Analysis

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2792
Author(s):  
Yunxu Chai ◽  
Changlai Xiao ◽  
Mingqian Li ◽  
Xiujuan Liang
Keyword(s):  
Water Quality ◽  
Groundwater Quality ◽  
Quality Evaluation ◽  
Control Mechanism ◽  
Groundwater Resources ◽  
Fuzzy Comprehensive Evaluation ◽  
Multivariate Statistical ◽  
Rock Interaction ◽  
Geological Conditions ◽  
Development And Management

Hydrogeochemical research and water quality evaluation are an important part of groundwater development and management projects in Dehui City, Jilin Province, China. We collected 217 groundwater samples in the study area and used two multivariate statistical methods, hierarchical cluster analysis and principal component analysis to classify groundwater; combined graphical method, piper diagram, and Gibbs diagram to characterize groundwater chemical types and distinguish the water chemical control mechanism; and fuzzy comprehensive evaluation method to evaluate groundwater quality. Three major categories have been identified. Most of the groundwater in the study area is Ca-HCO3 type water. The water chemistry control mechanism is determined to be based on water-rock interaction and less evaporation. From east to west in the study area, the total dissolved solids (TDS) gradually increased, and water quality gradually deteriorated. In the whole region, 79.26% of the groundwater is suitable for drinking. With Yinma River at the boundary, the water quality in the eastern part is excellent, while that in the southwest is poor. After appropriate treatment, it can be used in industry and agriculture. The excess NO3− is mainly affected by human activities. The unique geological conditions of the Songnen Plain result in an excess amount of Fe3+ and Mn2+ in some areas. This study determined the chemical characteristics of groundwater in the study area and distinguished water quality levels. The results will be helpful for the development and management of groundwater resources.

scholarly journals Urbanisation effects on groundwater chemical quality: findings focusing on the nitrate problem from 2 African cities reliant on on-site sanitation

2007 ◽  
Vol 5 (3) ◽  
pp. 441-454 ◽  
Author(s):  
Aidan A. Cronin ◽  
Alfred W. Hoadley ◽  
James Gibson ◽  
Ned Breslin ◽  
Fatoumata Kouonto Komou ◽  
...  
Keyword(s):  
Public Health ◽  
Groundwater Quality ◽  
Urban Areas ◽  
Groundwater Resources ◽  
Health Benefit ◽  
Chloride Content ◽  
Subsurface Water ◽  
African Cities ◽  
Disposal Option ◽  
The Impact

By 2010 Africa's urban population will have grown to over 420 million with on-site sanitation the predominant excreta disposal option. The use of on-site sanitation has important public health benefits but can result in large faecally derived loadings of nitrogen and chloride to groundwater resources. Nitrate is of particular concern, with elevated concentrations linked to potentially serious health problems. N and Cl can derive from natural sources so it is important to quantify the additional impact of human activities. Several authors have used empirical relationships between nitrate and chloride concentrations to assess the extent to which excreta influences groundwater quality. However, these relationships have assumed fixed loadings from excreta. Relationships between N and Cl have been extended here by adding country-specific estimates of average annual per capita nitrogen and chloride content of, and loading from, excreta. The results are compared with groundwater monitoring results from two very different mid-sized African cities (Timbuktu, Mali and Lichinga, Mozambique) where the vast majority of residents use on-site sanitation and are dependent on the subsurface water for drinking purposes. The results illustrate the impact of urbanisation on groundwater quality. They are compared with data from other African cities to allow the calculation of a general nitrate and chloride relationship for unsewered African urban areas. Potential interventions to help arrest rising nitrate levels and so provide a public health benefit are also examined.

scholarly journals Assessment of groundwater quality by using statistical analysis from kopargaon taluka, Ahmednagar, India

2016 ◽  
Vol 4 (2) ◽  
pp. 15
Author(s):  
Deshpande A.V. ◽  
Patil S.N.
Keyword(s):  
Statistical Analysis ◽  
Correlation Analysis ◽  
Groundwater Quality ◽  
Negative Correlation ◽  
Monsoon Season ◽  
Pearson Correlation ◽  
Post Monsoon ◽  
Post Monsoon Season ◽  
Different Sources ◽  
Descriptive Statistical Analysis

The study was conducted to evaluate the groundwater quality along the Kopargaon taluka. Thirty six ground water samples were collected from different sources in pre monsoon and post monsoon season, during the year 2013. The descriptive statistical analysis was carried out besides Pearson correlation. Correlation analysis revealed that very strong correlation exists between HCO3and Na(0.961), HCO3and Mg++ (0.935), HCO3and EC (0.927). Where highly negative correlation is observed between Na and pH (-0.537) during pre-monsoon season. During post monsoon season highly positive correlation is observed between Cl- and Ca++ (0.973), Ca and EC (0.967), Cl- and EC (0.966), SO4 and EC (0.948). Where, highly negative correlation is observed between Ca and pH (-0.533).

Application of TOPSIS Model Based on Vague Set Entropy in the Evaluation of Groundwater Quality

2013 ◽  
Vol 712-715 ◽  
pp. 452-456 ◽  
Author(s):  
Wen Zhong Yu ◽  
De Shan Tang
Keyword(s):  
Groundwater Quality ◽  
Quality Assessment ◽  
Quality Evaluation ◽  
Groundwater Resources ◽  
Sustainable Use ◽  
Evaluation Process ◽  
Irrigation District ◽  
Vague Set ◽  
Groundwater Quality Assessment ◽  
Model Based

Groundwater quality assessment had important guiding significance on sustainable use of groundwater resources. In order to avoid the subjective judgment on the weight of each index, this article used the Vague set entropy theory to determine the weight of each index, combined with the TOPSIS method, it established the TOPSIS groundwater quality evaluation model based on Vague set entroy. Finally, this model was applied to groundwater quality evaluation in Tailan River Irrigation District, the evaluation results matched with the actual situation. The results showed that the evaluation process of this model was reasonable and scientific, it provided a new idea for groundwater quality assessment.

Exploring the hydrogeological functioning and microbial habitats of the deep hillslope aeration zone in limestone-mudrock alternations

2020 ◽  
Author(s):  
Robert Lehmann ◽  
Cassandre Sara Lazar ◽  
Kirsten Küsel ◽  
Kai Uwe Totsche
Keyword(s):  
Groundwater Quality ◽  
Environmental Changes ◽  
Earth Science ◽  
Groundwater Resources ◽  
Archaeal Community ◽  
Critical Zone ◽  
Aeration Zone ◽  
Monitoring Wells ◽  
Rock Fragments ◽  
Directional Flow

<p>The aeration zone beneath topographic groundwater recharge areas, comprising variably water-saturated soil, regolith and bedrock is a typically large but hardly explored compartment of the Critical Zone. Fluid and matter exchange within the deep hillslope aeration zone, the dynamics of its diverse microbial dwellers and their contribution for subsurface matter cycling and groundwater quality are widely unknown. In the Hainich Critical Zone Exploratory (Collaborative Research Center AquaDiva, Küsel et al., 2016), we accessed the aeration zone and groundwater resources in fractured limestone-mudstone alternations by exploratory drillings and hillslope monitoring wells. Multi-year groundwater sampling, environmental monitoring, drill core and petrological analyses revealed a multi-storey architecture of the aeration zone, covering perched water bodies and multi-directional flow phenomena (Lehmann and Totsche 2020). In a ~50 m deep well that underwent pronounced seasonal head fluctuation up to 25 m of oligotrophic groundwater, we incubated bedrock fragments that mimicked large fracture habitats and monitored the dynamic environmental conditions in the fractured mixed carbonate-/siliciclastic alternations as well. During groundwater-saturated colonization, successional exposure to seasonal de-saturation and re-saturation, we analyzed the bacterial and archaeal 16S rRNA diversity and found a diverse bacterial, and less diverse archaeal community, both including persistent genera that withstood the harsh environmental changes. In accordance with mature fracture-surfaces (drill cores), the colonized rock fragments were dominated by Gammaproteobacteria. General compositional differences to communities within the phreatic zone (i.e. groundwater and rock matrices), and shallow sources in soil, suggest a distinct subsurface microbiome that is hardly represented by ecological surveys that utilize groundwater or rock samples.</p><p> </p><p>References:</p><p>Küsel, K., Totsche, K. U., Trumbore, S. E., Lehmann, R., Steinhäuser, C., Herrmann, M. (2016). How deep can surface signals be traced in the critical zone? Merging biodiversity with biogeochemistry research in a central German Muschelkalk landscape. Frontiers in Earth Science 4 (32). https://doi.org/10.3389/feart.2016.00032</p><p>Lehmann, R., Totsche, K. U. (2020). Multi-directional flow dynamics shape groundwater quality in sloping bedrock strata. Journal of Hydrology 580. https://doi.org/10.1016/j.jhydrol.2019.124291</p>

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