Temporal Variation Of Groundwater Quality Research Articles

Impacts of land use changes on the spatiotemporal evolution of groundwater quality in the Yinchuan area, China, based on long-term monitoring data

Agricultural activities and rapid urbanization have significantly impacted groundwater quality, especially in semi-arid and arid regions. This study comprehensively evaluated the quality of phreatic and confined groundwater in the Yinchuan area, China, using long-term monitoring data from 1991 to 2018. Geospatial analysis model was employed to explore the spatiotemporal evolution of groundwater hydrochemistry. The effects of land use changes on groundwater quality were assessed using correlation analysis and a multiple linear regression model (MLR). The findings indicate significant temporal variations in groundwater quality, with phreatic water consistently exhibiting high salinity and hardness. The groundwater quality indices for phreatic water were frequently more polluted than confined water. From 1991 to 2018, the hydrochemical composition of phreatic water evolved from HCO3-Mg and HCO3•SO4-Mg to more complex forms such as HCO3•SO4•Cl-Mg and HCO3•Cl-Mg. In contrast, confined water predominantly maintained its HCO3-Mg type and HCO3•Cl-Na (Na•Mg) type water. Urban land had rapidly expanded in the past three decades, increasing by 318.75% compared to 1991. The water body and urban area diminished the quality of phreatic water. High salt water in increase of TDS, Cl–, SO42–, Mn, TH, NO3–, F–, and Fe into phreatic water. NO3–, NH4+, and F− in phreatic water could be impacted by human and industrial activity in urban areas. This study provides valuable insights for local decision-makers to effectively manage groundwater resources and solve issues of groundwater scarcity and water quality problems in arid and semi-arid locations.

A survey on spatial and temporal variations of groundwater quality and quantity index using Geographic Information System and Geostatistics (Case study: Bam- Narmashir plain)

A survey on spatial and temporal variations of groundwater quality and quantity index using Geographic Information System and Geostatistics (Case study: Bam- Narmashir plain)

TEMPORAL VARIATION OF GROUNDWATER QUALITY IN SLEMAN, YOGYAKARTA, INDONESIA

Groundwater quality evaluation is important to gain an insight of contamination source. It can later be utilized to review the implementation of a water resource management policy in a specific region. Aim: This study evaluate the short-term temporal variation of groundwater quality and its possible contamination source in Sleman, Yogyakarta. Methodology and Results: the statistical approach was utilized using boxplot, principle component analysis (PCA) and correlation matrices, to the data for 50 sampling sites. The data of groundwater quality are available from the local environmental authority of Environmental Agency Sleman.The box plots revealed that groundwater quality might largely influenced by rainfall in the area. The factor loading of PCA presented that the ratio of concentration of both chloride and TDS are the most varied of all samples, and the less variable parameter is fluoride. The pair of groundwater quality parameter which had strong correlation were varied in each year, except for TDS and chloride that showed strong correlation in all three years. Nitrite had strong correlation with iron in 2017 and, nitrite also had strong correlation with both manganese and fluoride in 2019. The existence of fluoride in correlation with other parameter might give an insight of contamination from livestock wastes, where in the study area there are many poultry and cow farms, and small scale chicken slaughter industries. Conclusion, significant and impact study: This study gives preliminary understanding on temporal variation of groundwater quality, for further research on groundwater quality in Sleman, Yogyakarta.

Spatial and temporal variation of groundwater quality around a volcanic mountain in northwest of Iran

A study on quality of groundwater in a volcanic region in northwest of Iran was carried out. Both spatial and temporal variations of the water quality were investigated using Geographical Information System and Groundwater Quality Index. The results show that 74% of the groundwater were of calcium bicarbonate type based on piper diagram. TDS values varied between 116 and 470 mg/L, and concentration of salts was high in the western part the Sahand Mountain compared to that of eastern parts. The groundwater quality parameters for the last 8 years were employed to investigate the temporal variation. GWQI was calculated to be 17 in 2011, while it was gently increasing so that in 2018 it reached 22, indicating that groundwater quality in the studied area is deteriorating. However, all the values indicated that the groundwater is still reaching the national water quality guidelines. Multivariate statistical analysis including Pearson correlation, cluster analysis, and Principal Component Analysis were also performed. The groundwater in the study area was divided into 2 distinct clusters based on their TDS values. In addition, PCA demonstrated 3 different components covering almost 86% of the water samples. Finally, it can be concluded that multivariate statistical techniques could be useful in identifying the natural and non-natural sources governing the groundwater quality.

GROUNDWATER QUALITY ASSESSMENT OF CHILANCHIL ABAY WATERSHED: THE CASE OF BAHIR-DAR CITY WASTE DISPOSAL SITE

Improper dump sites have served many years as an ultimate disposal site for all types of waste; municipal solid waste, industrial sewage and hazardous waste in developing countries such as Ethiopia. Physical, chemical and biological processes interact simultaneously to bring about the overall decomposition of the wastes (chemically laden leachate). If not, deal properly, such kind of dumping site can cause pollution to groundwater (because of Leachates) and surface water (through contaminant transportation by flooding and groundwater movements). Therefore, this study investigates the spatial and temporal variation of groundwater quality within the Chilanchil Abay watershed during dry and wet season due to the waste disposal site of the Bahir Dar city. Water samples were collected from 6 sampling points of groundwater from 30th March to 20th August by a monthly period. Over 10 water quality parameters such as pH, TDS, Electrical conductivity, Turbidity, Temperature, DO, BOD, COD, TC, NO3- and PO43–, were analyzed. Moreover, the overall status of the groundwater quality of the study area was evaluated by the Canadian Water Quality Index. Based on the result of this model the status of the groundwater sample points throughout the study area were raged from 42 to 46.2 (marginal status).

Countrywide Groundwater Quality Trend and Suitability for Use in Key Sectors of Korea

Under changing climate, increasing groundwater use has risen the concern for groundwater quality variations over recent years, to maintain a healthy ecosystem. The objectives were to identify trend of temporal variations in groundwater quality and its suitability for different uses in Republic of Korea. Water quality data were collected from 198 monitoring stations of Groundwater Quality Monitoring Network (GQMN), annually for the period of ten years (2008–2017). Non-parametric trend analysis of a Mann–Kendall test and Theil–Sen’s slope was done on groundwater physico-chemical data of ten years. Groundwater suitability evaluation was done for use in main sectors including domestic (drinking) and agriculture (irrigation). For drinking suitability analysis, results were compared with World Health Organization (WHO) and Korean Ministry of Environment (KME) established guidelines. For irrigation suitability evaluation, electrical conductivity (EC), Sodium Adsorption Ratio (SAR), percent of Na+, Residual Sodium Carbonate (RSC), US Salinity Laboratory (USSL), and Wilcox diagram were used. Most significantly, water type belongs to Ca-HCO3 and Ca-SO4 types, but a small proportion belongs to Na-CO3 and Na-Cl types. Approximately, 96% and 93% of groundwater samples are suitable for drinking, based on WHO and KME guidelines, respectively. Around 98% and 83% of groundwater samples are in suitable range for irrigation use, based on USSL and Wilcox diagrams, respectively.

Monthly physicochemical variation of tropical island groundwater of Pulau Bidong, south China sea

The groundwater of Pulau Bidong, Terengganu, Malaysia was investigated to monitor the quality of freshwater source. Groundwater samples were collected from five sampling stations from June 2016 to October 2016. Physical parameters such as temperature, specific conductivity, dissolved oxygen (DO), pH, salinity, and DO saturation were measured in-situ by using handheld device. Meanwhile, total suspended solid (TSS), total dissolved solid (TDS), nitrate (NO3−), nitrite (NO2−), ammonium (NH4+) and phosphate (PO43−) were also analysed. The inorganic nutrients of NO3−, NO2−, NH4+, and PO43− were ranged from 0.000 to 4.310 mg/L, 0.000–0.190 mg/L, 0.000–0.807 mg/L and 0.003–0.028 mg/L, respectively. The monthly trends of specific conductivity, DO, salinity, DO saturation, NH4, NO3 and NO2 demonstrated significant variation in June (the lowest rainfall) compared to other months. Correlation matrix revealed that temperature was associated with the specific conductivity, and NH4+ strongly correlated with DO, NO3− and NO2−. Nevertheless, there is a strong negative correlation between physicochemical parameters and monthly rainfall distribution. The physicochemical parameters were within the recommended safe limits suggested by the World Health Organization (WHO) and National Drinking Water Quality Standard (NDWQS) except for pH. Nevertheless, pH of water does not directly impact on the human health. Environmetrics analysis demonstrated that NO3− and PO43− significantly influenced the groundwater quality spatially. Furthermore, the temporal variation of groundwater quality was affected by pH and salinity. Overall, the groundwater sources from Pulau Bidong are considered safe to be used as drinking water. Notably, future studies are required for long-term monitoring to ensure the good quality of groundwaters from Pulau Bidong.

Evaluation of seasonal and temporal variations of groundwater quality around Jawaharnagar municipal solid waste dumpsite of Hyderabad city, India

The present study aimed to assess the impact of municipal solid waste dumpsite on groundwater bodies at Hyderabad, India. Leachate and groundwater samples collected through pre- and post-monsoon analyzed the physicochemical, microbiological, biological and heavy metals. The analytical data were compared with Bureau of Indian Standards (BIS) drinking water quality standards. Water quality index (WQI), heavy metal pollution indices like heavy metal evaluation index (HEI) and degree of contamination (Cd) are calculated for groundwater samples. High total dissolve solids values in leachates revealed that they were highly contaminated with organic and inorganic salts. Biological oxygen demand values indicated that dumpsite was “old and stabilized” with decreasing biodegradability from time to time. According to WQI, about 75% of the water samples identified as “Poor” category that is not suitable for neither drinking nor domestic purposes as per BIS standards. Similarly, HEI and Cd results indicated that majority of the samples are labeled with low-metal pollution status. Spatial patterns obtained through geographic information systems using inverse distance weighted interpolation technique revealed that the concentrations of various parameters are high due to increased degradation of solid wastes during rainfall, especially during the post-monsoon. The study suggested that leachates have treated prior to disposal on land, and continuous monitoring of groundwater wells is required to minimize the pollution and potential health hazards.

Groundwater pollution early warning based on QTR model for regional risk management: A case study in Luoyang city, China

Groundwater pollution early warning has been regarded as an effective tool for regional groundwater pollution prevention, especially in China. In this study, the systemic model was established to assess the groundwater pollution early warning by integrating the present situation of groundwater quality (Q), groundwater quality trend (T) and groundwater pollution risk (R). The model integrated spatial and temporal variation of groundwater quality, and combined the state and process of the groundwater pollution. Q, T and R were assessed by the methods of fuzzy comprehensive assessment, Spearman or nonparametric Mann-Kendall trend test, and overlay index, respectively. Taking the Luoyang City as an example, the groundwater pollution early warning mapping was generated, and verified by corresponding the groundwater quality classes and the early warning degrees. The results showed that the groundwater was dominated by the levels of no warning and light warning, which accounted for 77% of the study area. The serious and tremendous warning areas were affected by the worse trend and relatively bad/bad present situations of groundwater quality with the typical contaminants of total hardness, nitrate, Hg and COD. In summary, the present situation of groundwater quality was the most important factor of groundwater pollution early warning mapping in the study area. The worse trend of groundwater quality played equally a key role in the local regions, as well as the high pollution risk, which was mainly affected by the pollution source loading. Targeted measures for groundwater pollution prevention were proposed in the corresponding degrees of groundwater pollution early warning. The QTR model was proved to be effective for assessing the regional groundwater pollution early warning. The accuracy of the model could be improved if there is further data acquisition of groundwater quality in longer time series and in larger number, and further investigation of pollution sources.The QTR model is proposed and proved to be effective for assessing regional groundwater pollution early warning.

Spatial and Temporal Variation of Groundwater Quality within Omdurman Locality Geological Zone

Water is essential for all forms of life. Groundwater is one of the main sources of water supply in many countries. Exploration report by the Water Research Institute indicated that 90% and 25% of the rural and urban communities uses groundwater sources for their domestic use respectively. Chemical composition of water may be rendered unfit for human consumption, and thus may lead to health problems. The importance of groundwater quality in human health has recently attracted a great deal of interes

Groundwater pollution source apportionment using principal component analysis in a multiple land-use area in southwestern China.

Identification of different pollution sources in groundwater is challenging, especially in areas with diverse land uses and receiving multiple inputs. In this study, principal component analysis (PCA) was combined with geographic information system (GIS) to explore the spatial and temporal variation of groundwater quality and to identify the sources of pollution and main factors governing the quality of groundwater in a multiple land-use area in southwestern China. Groundwater samples collected from 26 wells in 2012 and 38 wells in 2018 were analyzed for 13 water quality parameters. The PCA results showed that the hydro-geochemical process was the predominant factor determining groundwater quality, followed by agricultural activities, domestic sewage discharges, and industrial sewage discharges. Agriculture expansion from 2012 to 2018 resulted in increased apportionment of agricultural pollution. In contrast, economic restructure and infrastructure improvement reduced the contributions of domestic sewage and industrial pollution. Anthropogenic activities were found the major causes of elevated nitrogen concentrations (NO3-, NO2-, NH4+) in groundwater, highlighting the necessity of controlling N sources through effective fertilizer managements in agricultural areas and reducing sewage discharges in urban areas. The applications of GIS and PCA successfully identified the sources of pollutants and major factors driving the variations of groundwater quality in tested years.

Spatial and Temporal Variations of Groundwater Quality for Agricultural Use in Gavkhooni Basin

Spatial and Temporal Variations of Groundwater Quality for Agricultural Use in Gavkhooni Basin

Temporal variation in ground water quality due to urbanization. Case study: District Peshawar, Pakistan

Groundwater is a significant source of water for both domestic and agricultural use. The main objective of this study was to identify temporal variations in groundwater quality of Peshawar by developing GIS based physio-chemical parameters contour maps, comparative graphs and analyse results in light of Pakistan Standard Quality Control Authority (PSQCA). In 2005, same study for district Peshawar was carried out jointly by PCSIR Peshawar and Kyungpook National University. In order to assess the effects of urbanization on ground water quality in district Peshawar, another study was undertaken in 2014-15 by collecting samples from the same locations. Standard procedures were adopted to determine the selected parameters and results of both the studies were compared. Comparative analysis of both the studies showed that some of the chemical parameters values gained an increase while other got decreased. Results also showed that electrical conductivity (EC), Cl-, SO4-2, NO3-1 were increased by 119.11%, 29.98%, 469.60%, and 59.47% respectively, while total dissolved solids (TDS), turbidity, total alkalinity, total hardness, calcium (Ca++), HCO3-1 and Magnesium (Mg++) were decreased by 6%, 10.51%, 37.39% and 11.52%, 22.21%, 37.56% and 21.19% respectively. Results revealed that changes in water quality have occurred due to over population of Peshawar and remedial measures are needed in future.

Geo-statistical analysis of groundwater quality in an unconfined aquifer of Nethravathi and Gurpur river confluence, India

The groundwater quality plays a vital role in domestic, industrial and agricultural water supply. However, seawater intrusion was one of the major problems occur worldwide in the coastal aquifers due to excessive pumping of fresh groundwater. Thus, groundwater gets contaminated due to seawater intrusion, disposal of industrial waste etc. Due to this reason, it becomes necessary for regular monitoring of groundwater quality, in order to take proper measures for avoiding and reducing contamination. Hence, the present study was aimed to assess water quality in Nethravathi and Gurpur river confluence, located on the west coast of India. Groundwater samples were collected for the month of January 2013–May 2017, which was further analysed in the laboratory as per Bureau of Indian Standards (BIS) and World Health Organisation (WHO) standards. The water quality parameters considered for analysis are Potential Hydrogen (pH), Sodium (Na), Potassium (K), Electrical conductivity (EC), Chloride (Cl), Total Dissolved Solids (TDS), Calcium (Ca), Magnesium (Mg), Total Hardness (TH) and Bicarbonate (HCO3). The results of these parameters were further mapped using Geographical Information System (GIS) to visualize spatial distribution. The geo-statistical analysis was also carried out using SPSS tool to know the correlation of these parameters. The regression analysis was carried out with Factor of sea to the chemical parameters such as Bicarbonate (HCO3), Electrical Conductivity (EC), Total Dissolved Solids (TDS), Calcium (Ca), Magnesium (Mg) and Total Hardness (TH). The significant groundwater quality chemical parameters were found by correlation analysis. The significant groundwater quality chemical parameters were further given as input for mapping, prediction and modelling of groundwater quality. The prediction of significant parameters carried out using the monthly groundwater quality data for the year 2013 and 2014. The result of spatial mapping and statistical analysis provides the spatial and temporal variation of groundwater quality in the study area. The results showed that only Panganimuguru and Kunjatbail region is affected by seawater. The modelling results of Cl and TDS shows the spatial occurrence of contamination in the study area of Netravathi and Gurpur river confluence at the various time period. Further, the results of the modelling also show that the contamination occurs up to a distance of 519 m towards the freshwater zone of the study area.

Application of the Risk-Based Early Warning Method in a Fracture-Karst Water Source, North China.

The paper proposes a risk-based early warning considering characteristics of fracture-karst aquifer in North China and applied it in a super-large fracture-karst water source. Groundwater vulnerability, types of land use, water abundance, transmissivity and spatial temporal variation of groundwater quality were chosen as indexes of the method. Weights of factors were obtained by using AHP method based on relative importance of factors, maps of factors were zoned by GIS, early warning map was conducted based on extension theory with the help of GIS, ENVI+IDL. The early warning map fused five factors very well, serious and tremendous warning areas are mainly located in northwest and east with high or relatively high transmissivity and groundwater pollutant loading, and obviously deteriorated or deteriorated trend of petroleum. The early warning map warns people where more attention should be paid, and the paper guides decision making to take appropriate protection actions in different warning levels areas.

Groundwater quality assessment of urban Bengaluru using multivariate statistical techniques

Groundwater quality deterioration due to anthropogenic activities has become a subject of prime concern. The objective of the study was to assess the spatial and temporal variations in groundwater quality and to identify the sources in the western half of the Bengaluru city using multivariate statistical techniques. Water quality index rating was calculated for pre and post monsoon seasons to quantify overall water quality for human consumption. The post-monsoon samples show signs of poor quality in drinking purpose compared to pre-monsoon. Cluster analysis (CA), principal component analysis (PCA) and discriminant analysis (DA) were applied to the groundwater quality data measured on 14 parameters from 67 sites distributed across the city. Hierarchical cluster analysis (CA) grouped the 67 sampling stations into two groups, cluster 1 having high pollution and cluster 2 having lesser pollution. Discriminant analysis (DA) was applied to delineate the most meaningful parameters accounting for temporal and spatial variations in groundwater quality of the study area. Temporal DA identified pH as the most important parameter, which discriminates between water quality in the pre-monsoon and post-monsoon seasons and accounts for 72% seasonal assignation of cases. Spatial DA identified Mg, Cl and NO3 as the three most important parameters discriminating between two clusters and accounting for 89% spatial assignation of cases. Principal component analysis was applied to the dataset obtained from the two clusters, which evolved three factors in each cluster, explaining 85.4 and 84% of the total variance, respectively. Varifactors obtained from principal component analysis showed that groundwater quality variation is mainly explained by dissolution of minerals from rock water interactions in the aquifer, effect of anthropogenic activities and ion exchange processes in water.

Groundwater quality assessment for domestic and agriculture purposes in Puducherry region

Totally about 174 groundwater samples have been collected during pre-monsoon and post-monsoon season to study the suitability for domestic and agriculture purposes along the coastal aquifers of Puducherry region. Parameters such as pH, total dissolved solids (TDS), electrical conductivity (EC), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), bicarbonate (HCO3), chloride (Cl) and sulfate (SO4) were analyzed to assess the suitability of groundwater for domestic purposes. Sodium adsorption ratio (SAR), magnesium adsorption ratio (MAR), residual sodium bicarbonate (RSC), soluble sodium percentage (Na%), permeability index (PI) and chlorinity index were assessed for irrigation purposes. The higher concentration of ions such as Na, Ca, Cl and So4 indicates seawater intrusion, mineral dissolution, intense agricultural practices and improper sewage disposal. The level of EC, TDS and hardness in the water samples indicates that maximum of them are suitable for drinking and domestic purposes. The parameters such as SAR, Na%, PI, MAR and Chlorinity index indicates that majority of water sample are very good to moderately suitable for agriculture. In pre-monsoon, RSC of about 5.7% of samples was higher which when used for a longer time alter the soil properties and reduce crop production. Wilcox diagram suggests that water samples are of medium saline to low sodium type indicating that groundwater is suitable for irrigation. Temporal variation of groundwater quality shows significant increasing trend in EC, TDS and ions like Mg, K and Cl in the last decade, mainly due to anthropogenic activities with little geogenic impact in the quality of groundwater.

Temporal Variations in Groundwater Quality with Special Reference to Irrigation in Faridkot and Muktsar Areas of Southwest Punjab, India

Temporal Variations in Groundwater Quality with Special Reference to Irrigation in Faridkot and Muktsar Areas of Southwest Punjab, India

Groundwater Quality in an Upland Agricultural Watershed in the Sub-Humid Ethiopian Highlands

Agricultural intensification to meet the food needs of the rapidly growing population in developing countries is negatively affecting the water quality. In most of these countries such as Ethiopia, information on surface and especially groundwater quality is lacking. This limits the measure that can be taken to stop pollution. We, therefore, investigated the spatial and temporal variation of groundwater quality in the upland watershed. Tikur-Wuha watershed was selected because it is located in the Lake Tana watershed, which is seeing the first signs of eutrophication. Groundwater samples were collected from July 2014 to June 2015 from 19 shallow wells located throughout the watershed. Collected water samples were analyzed both in situ and in the laboratory to determine pH, electric conductivity (EC) and total dissolved solid (TDS), concentration of chemicals (nitrate, dissolved phosphorus, calcium, magnesium, aluminum and iron) and Escherichia coli (E. coli). We found that shallow groundwater had greater chemical concentrations and E. coli level in the monsoon rain phase than in the dry phase. Wells located down slope exhibited greater concentrations than mid- and upper-slope positions, with the exception of the nitrate concentration that was less down slope, due to denitrification in the shallow groundwater. Only E. coli level was above the WHO drinking water quality standards. Further studies on groundwater quality should be carried out to understand the extent of groundwater contamination.

Temporal variations of groundwater quality in the Western Jianghan Plain, China

The Western Jianghan Plain (WJHP) lies in the middle reaches of the Yangtze River. It has been impacted by anthropogenic activities during the past decades. The long-term variations of the WJHP's regional aquifer's hydrochemistry and groundwater quality have not been previously assessed. Sixteen physiochemical parameters at 29 monitoring wells within the Western Jianghan Plain were monitored during 1992–2010 and analyzed with multiple approaches. The confined groundwater is predominantly of the HCO3-Ca-Mg type with Cl−, SO42−, NH4-N, and NO3-N showing remarkable spatial variations. Correlation analysis was used to identify the origins and contamination sources of groundwater. The seasonal Mann-Kendall test revealed that pH, NO3-N, and Cl− concentrations at 27, 26 and 15 wells, respectively, exhibited significant increasing trends during 1992–2010. The increase of pH may be attributed to CO2 degassing caused by extensive groundwater extraction. Regional average NO3-N concentrations of groundwater increased coincidently with the increased use of fertilizer, which suggests that nitrate pollution is caused by agricultural activities. Abnormally high values of Cl− and SO42− at some wells were induced by industrial chemicals. In addition, the similarity of the temporal variations of the regional average of pH, NH4-N, and NO3-N concentrations in groundwater with those in the Yangtze River at the outlet of the Three Gorges Reservoir (TGR) suggests that the variations of these parameters in the WJHP is partly due to water storage by the TGR. This study presents an analysis of temporal variations of groundwater quality in the WJHP that reveals a relation between the creation of the TGR and downstream groundwater quality. This paper's findings provide clues for measures that could be taken to protect the groundwater quality of the WJHP's aquifer.