scholarly journals Nitrate contamination in groundwater agricultural of Samno and Elzegan area, Fazan region, Libya

2018 ◽  
Vol 7 (2.29) ◽  
pp. 56 ◽  
Author(s):  
Mabroka Mohamed Daw ◽  
Elhadi Ramadan Ali ◽  
Mohd Ekhwan Toriman
Keyword(s):  
Water Samples ◽  
Nitrate Pollution ◽  
Nitrate Contamination ◽  
Public Utilities ◽  
Major Portion ◽  
Agricultural Activities ◽  
Paper Study ◽  
Chemical Fertilizers ◽  
Groundwater Samples

This paper study explores the groundwater nitrate pollution associated with agricultural activities in Samno and Elzegan areas, Libya. The study’s main aim is to evaluate the condition of groundwater agricultural in the study area. 40 water samples were collected from forty established wells used of daily domestic and public utilities from first of January to end of July 2014 the samples were collected subjected from different aquifer levels and depths. The water samples’ NO3 concentration was measured using the hack-spectrophotometer nitrate test. The findings revealed that a major portion of the groundwater samples had a significant NO3 concentration; only 12.5% wells were recorded at the saver level. Meanwhile, 87% wells were recorded as polluted with NO3, 27.5 % wells were in severing level and 60% wells were recorded as slightly to moderate levels. The main sources of NO3 in the groundwater come from an excessive use of chemical fertilizers and pesticides. This study recommends that most of the wells operated within the study areas are not suitable for any household or agricultural purposes.  

scholarly journals SEAWATER INTRUSION AND NITRATE POLLUTION IN COASTAL AQUIFER OF MARATHON BASIN

2017 ◽  
Vol 50 (2) ◽  
pp. 927 ◽  
Author(s):  
P. Papazotos ◽  
I. Koumantakis ◽  
E. Vasileiou
Keyword(s):  
Spatial Distribution ◽  
Seawater Intrusion ◽  
Coastal Plain ◽  
Coastal Aquifer ◽  
Nitrate Pollution ◽  
Average Concentration ◽  
Agricultural Activities ◽  
Chemical Analyses ◽  
Groundwater Salinization ◽  
Groundwater Samples

The overexploitation of groundwater and groundwater salinization cause quantitative and qualitative degradation of the water resources. The objectives of this research are to identify and investigate the extent of seawater intrusion and nitrate pollution into the coastal plain of Marathon in Eastern Attica, Greece. In the frame of this, 25 groundwater samples were collected in October 2014 from the study area and analyzed regarding the main parameters that indicated salinization of the aquifers. Specifically, water chemical analyses were carried out and statistical analyses regarding spatial distribution were performed. The results demonstrated increased values of the parameters which can be associated with seawater intrusion. Considering and evaluating the results from the chemical analyses it is obvious that seawater intrusion takes place in the area. Furthermore, the average concentration of NO3- was 44.16mg L-1 and this can be attributed to overexploitation of coastal aquifer for agricultural activities.

scholarly journals Assessment of Groundwater Contamination Hazard by Nitrate in Samas Area, Bantul District, Yogyakarta, Indonesia

2017 ◽  
Vol 2 (1) ◽  
pp. 36 ◽  
Author(s):  
Thilavanh Souvannachith ◽  
Doni Prakasa Eka Putra ◽  
Heru Hendrayana
Keyword(s):  
Groundwater Contamination ◽  
Water Samples ◽  
Groundwater Resources ◽  
Shallow Groundwater ◽  
Groundwater Vulnerability ◽  
Nitrate Contamination ◽  
High Class ◽  
Settlement Area ◽  
Groundwater Samples ◽  
Potential Map

Groundwater resource is an essential for various purposes in Bantul district, Yogyakarta Special Province, Indonesia, especially on Poncosari village where the water supply are depending on shallow groundwater resources. On this village, most of the houses using dug wells to provide their water needs and applying inappropriate on-site sanitation system, however there are also difference land uses. This condition increase the hazard of groundwater contamination by fecal coli bacteria and nitrate. Therefore, this research aims in term of three main objectives: firstly, to know the level of nitrate concentration in groundwater, secondly, to assess groundwater vulnerability and thirdly, to assess the level of groundwater contaminant hazard. Hydrogeology observation was conducted and 47 water samples (44 groundwater samples and 3 surface water samples) were collected from different land use type and analyze for nitrate (NO 3) content. Methodology used to assess the groundwater vulnerability was Simple Vertical Vulnerability method and the groundwater contamination hazard built based on the combination of groundwater vulnerability and nitrate loading potential map. Results show that groundwater concentrations of nitrate range from 0.09–74.80 mg/L and the highest concentration found in the settlement area. Assessment of groundwater vulnerability reveals three areas of moderate, moderate high and high classes of vulnerability due to shallow groundwater and the sandy dominated overlying material in the study area. Combination of groundwater vulnerability and nitrate loading potential map indicated that groundwater contaminant hazard of nitrate range from low to high class. High class of hazard located in the settlement area, and low hazard of nitrate contamination found in the irrigated rice field area

scholarly journals Modified DRASTIC model for groundwater vulnerability to nitrate contamination in the Dagujia River Basin, China

2021 ◽  
Author(s):  
Aihua Wei ◽  
Pan Bi ◽  
Jie Guo ◽  
Shuai Lu ◽  
Duo Li
Keyword(s):  
Land Use ◽  
Mean Squared Error ◽  
Groundwater Vulnerability ◽  
Nitrate Pollution ◽  
Nitrate Contamination ◽  
Support Vector ◽  
Drastic Model ◽  
Rapid Economic Growth ◽  
Groundwater Samples ◽  
Over Exploitation

Abstract Due to rapid economic growth and over-exploitation of groundwater, nitrate pollution in groundwater has become very serious. The main objective of this study is to modify the DRASTIC model to identify groundwater vulnerability to nitrate pollution. The DRASTIC model was firstly used to analyze the intrinsic vulnerability. The DRASTIC model with the inclusion of a land-use factor (DRASTIC-LU) was put forward to map the specific vulnerability of groundwater. Furthermore, the Support Vector Machine (SVM) was introduced to avoid the drawback of the overlay and index methods, and the improved integrated models of DRASTIC + SVM and DRASTIC-LU + SVM were built. Moreover, 103 groundwater samples were collected for building and validating the models. The Root Mean Squared Error (RMSE) of DRASTIC, DRASTIC-LU, DRASTIC + SVM, and DRASTIC-LU + SVM was found to be 0.853, 0.755, 0.631, and 0.502, respectively. The model DRASTIC-LU was more precise than the original one. The results also showed that the integrated model using SVM exhibited better correlation between the vulnerability value and the nitrate pollution. The study indicated that the modified models including the land-use factor as well as SVM in the DRASTIC model were more suitable to assess the groundwater vulnerability to nitrate.

scholarly journals Spatial variability of nitrate pollution and its sources in a hilly basin of the Yangtze River based on clustering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuhuan Cui ◽  
Jie Wang ◽  
Shuang Hao
Keyword(s):  
Surface Water ◽  
Yangtze River ◽  
Drainage Basin ◽  
Quality Standard ◽  
Nitrate Pollution ◽  
Middle Part ◽  
Lake Basin ◽  
The Yangtze River ◽  
Nitrate Sources ◽  
Groundwater Samples

AbstractNitrate (NO3−) pollution is a serious global problem, and the quantitative analysis of its sources contributions is essential for devising effective water-related environmental-protection policies. The Shengjin Lake basin, located in the middle to lower reaches of the Yangtze River in China was selected as the research area in our study. We first grouped 29 surface water samples and 33 groundwater samples using cluster analysis, and then analyzed potential nitrate sources for each dataset of δ15N–NO3− and δ18O–NO3− isotope values by applying a Bayesian isotope-mixing model. Our results show that the nitrogen pollution in the surface-ground water in the study area seriously exceeded to class V of the Environmental Quality Standard of Surface Water of China. The NO3− in surface water from the mid-upper reaches of the drainage basin mainly originates from soil nitrogen (SN) and chemical fertilizer (CF), with contribution rates of 48% and 32%, respectively, and the NO3− in downstream areas mainly originates from CF and manure and sewage (MS), with contribution rates of 48% and 33%, respectively. For the groundwater samples, NO3− mainly originates from MS, CF, and SN in the mid-upper reaches of the drainage basin and the northside of Dadukou near the Yangtze River, with contribution rates of 34%, 31%, and 29%, respectively, whereas NO3− in the lower reaches and the middle part of Dadukou mainly originates from MS, with a contribution rate of 83%. The nitrogen conversion of surface water in lakes and in the mid-upper reaches is mainly affected by water mixing, while the groundwater and surface water in the lower plains are mainly affected by denitrification. The method proposed in this study can expand the ideas for tracking nitrate pollution in areas with complex terrain, and the relevant conclusions can provide a theoretical basis for surface and groundwater pollution control in the hilly basin of Yangtze River.

Water and nitrogen balance assessment for Krško polje aquifer case study in Slovenia

2021 ◽  
Author(s):  
Miha Curk ◽  
Matjaž Glavan ◽  
Marina Pintar ◽  
Vesna Zupanc
Keyword(s):  
Land Use ◽  
Nitrogen Balance ◽  
Swat Model ◽  
Nitrate Pollution ◽  
Alluvial Plain ◽  
Agricultural Activities ◽  
Balance Assessment ◽  
Land Use Types ◽  
Set Up

<p>Groundwater is the main source of drinking water in Slovenia, but nitrate pollution originating from agricultural activities as well as urban sources such as faulty sewage systems is threatening its quality in several areas of the country. One of such is the Krško-brežiško polje alluvial plain in the southeast. The main aim of this study was to assess the water and nitrogen balance for three common land-use types, as well as the whole area. Three field trial sites were set up to monitor water and nitrogen balance. Gaps in data were further evaluated by SWAT model simulations. Results will contribute to the existing knowledge of nitrate pollution pathways in the area, and strengthen understanding of land use and soil type’s influence on the process.</p><p>This work was funded by the Slovenian Research Agency project L4-8221 and IAEA TCP-SLO5004.</p>

Transformations and nitrate sources in an agricultural watershed(Quanshui River, China): An investigation using hydrogeochemistry, isotopes, and a Bayesian model

2021 ◽  
Author(s):  
Mingda Cao
Keyword(s):  
Surface Water ◽  
Bayesian Model ◽  
Field Investigation ◽  
Climatic Conditions ◽  
Agricultural Watershed ◽  
Agricultural Activities ◽  
Transformation Mechanism ◽  
Chemical Fertilizers ◽  
Nitrate Sources ◽  
The Difference

<p>The spatiotemporal changes of nitrate in agricultural watersheds are of global concern. Although numerous studies have explained the source and transformation mechanism of nitrate in groundwater and surface water, the transformation mechanism in groundwater remains poorly understood because of different hydrogeological and climatic conditions. Based on a field investigation and sampling, this study revealed the sources and transformation mechanism of nitrogen in surface water and groundwater in a karst agricultural watershed by comprehensively using water chemistry data, isotope components, and a Bayesian model (simmr). The results indicated that:1)Local agricultural activities have controlled the changes of δ<sup>15</sup>N-NO<sub>3</sub><sup>-</sup>, δ<sup>18</sup>O-NO<sub>3</sub><sup>-</sup> and δ<sup>15</sup>N-NH<sub>4</sub><sup>+</sup> in groundwater. The difference is that the concentration of NO<sub>3</sub><sup>-</sup> is significantly affected by rainfall. However, the contribution of rainfall to groundwater NO<sub>3</sub><sup>-</sup> is relatively small (<9%), indicating that there is a dual influence mechanism of leaching in the watershed that controls the concentration of groundwater NO<sub>3</sub><sup>-</sup>, while agricultural activities control its isotope changes;2)The study observed that after fertilization, due to the influence of ammonia volatilization and nitrification, δ<sup>15</sup>N-NO<sub>3</sub><sup>-</sup>, δ<sup>18</sup>O-NO<sub>3</sub><sup>-</sup> in groundwater showed a simultaneous decrease, while δ<sup>15</sup>N-NH<sub>4</sub><sup>+</sup> showed an increasing trend, which may be due to the result of incomplete nitration of NH<sub>4</sub><sup>+</sup> in the vadose zone;3)According to the calculation results of the simmr model, in the two main fertilization periods in October 2018 and April 2019, the contribution of chemical fertilizers to groundwater NO<sub>3</sub><sup>-</sup>reached the peak value(65% and 69%), which is in line with the seasonal variations of δ<sup>15</sup>N-NO<sub>3</sub><sup>-</sup>, δ<sup>18</sup>O-NO<sub>3</sub><sup>-</sup>and δ<sup>15</sup>N-NH<sub>4</sub><sup>+</sup>;4)The surface water in the watershed is mainly supplied by groundwater, and the contribution of chemical fertilizers to surface water NO<sub>3</sub><sup>-</sup> is generally higher than that of groundwater. This may be caused by the drainage of rice fields containing chemical fertilizers into the river.</p>

scholarly journals A meta-analysis and statistical modelling of nitrates in groundwater at the African scale

2016 ◽  
Vol 20 (6) ◽  
pp. 2353-2381 ◽  
Author(s):  
Issoufou Ouedraogo ◽  
Marnik Vanclooster
Keyword(s):  
Statistical Model ◽  
Nitrate Concentration ◽  
Regional Scale ◽  
Shallow Groundwater ◽  
Statistical Modelling ◽  
Nitrate Pollution ◽  
Nitrate Contamination ◽  
Data Set ◽  
Nitrate Concentrations ◽  
Groundwater Systems

Abstract. Contamination of groundwater with nitrate poses a major health risk to millions of people around Africa. Assessing the space–time distribution of this contamination, as well as understanding the factors that explain this contamination, is important for managing sustainable drinking water at the regional scale. This study aims to assess the variables that contribute to nitrate pollution in groundwater at the African scale by statistical modelling. We compiled a literature database of nitrate concentration in groundwater (around 250 studies) and combined it with digital maps of physical attributes such as soil, geology, climate, hydrogeology, and anthropogenic data for statistical model development. The maximum, medium, and minimum observed nitrate concentrations were analysed. In total, 13 explanatory variables were screened to explain observed nitrate pollution in groundwater. For the mean nitrate concentration, four variables are retained in the statistical explanatory model: (1) depth to groundwater (shallow groundwater, typically < 50 m); (2) recharge rate; (3) aquifer type; and (4) population density. The first three variables represent intrinsic vulnerability of groundwater systems to pollution, while the latter variable is a proxy for anthropogenic pollution pressure. The model explains 65 % of the variation of mean nitrate contamination in groundwater at the African scale. Using the same proxy information, we could develop a statistical model for the maximum nitrate concentrations that explains 42 % of the nitrate variation. For the maximum concentrations, other environmental attributes such as soil type, slope, rainfall, climate class, and region type improve the prediction of maximum nitrate concentrations at the African scale. As to minimal nitrate concentrations, in the absence of normal distribution assumptions of the data set, we do not develop a statistical model for these data. The data-based statistical model presented here represents an important step towards developing tools that will allow us to accurately predict nitrate distribution at the African scale and thus may support groundwater monitoring and water management that aims to protect groundwater systems. Yet they should be further refined and validated when more detailed and harmonized data become available and/or combined with more conceptual descriptions of the fate of nutrients in the hydrosystem.

scholarly journals Hydrochemical Characteristics of Groundwater and Dominant Water–Rock Interactions in the Delingha Area, Qaidam Basin, Northwest China

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 836 ◽  
Author(s):  
Biao Zhang ◽  
Dan Zhao ◽  
Pengpeng Zhou ◽  
Shen Qu ◽  
Fu Liao ◽  
...  
Keyword(s):  
Water Samples ◽  
Qaidam Basin ◽  
Flow Direction ◽  
Groundwater Resources ◽  
Saturation Index ◽  
Northwest China ◽  
Ion Concentration ◽  
Groundwater Samples ◽  
Mountain Front ◽  
Rational Management

Groundwater is undoubtedly important for water supplies and eco-environment protection, especially for arid and semi-arid regions. Analyzing the characteristics and evolution of groundwater is significant for the rational management of groundwater resources. This study investigated the hydrogeochemical characteristics and evolutions of groundwater in the Delingha area, northeast of the Qaidam Basin, northwest China, with a total of 123 water samples, including 105 unconfined groundwater samples, 12 confined groundwater samples, and 6 surface water samples. Hydrochemical results showed that the unconfined and confined groundwater presented diversity in ion concentration. Total Dissolved Solids (TDS) of the unconfined groundwater increased from 146.5 to 8954 mg/L along the groundwater flow direction. The groundwater hydrochemical types were HCO3-Ca·Mg and HCO3·SO4-Ca·Mg in the mountain front area, SO4·HCO3-Ca·Mg and SO4·Cl-Ca·Mg types in the alluvial-lacustrine plain, and Cl·SO4-Na and Cl-Na types in the lacustrine plain. The saturation index showed that parts of the groundwater samples were supersaturated with carbonate minerals (calcite and dolomite); however, all the samples were undersaturated with evaporite minerals (halite and gypsum). Groundwater chemical evolution is mainly controlled by evaporite and carbonate mineral dissolutions, aluminosilicates weathering, and cation exchange.

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