Variation of groundwater hydrochemical characteristics in the plain area of the Tarim Basin,Xinjiang Region,China

Groundwater hydrochemistry could reveal the interaction mechanism between groundwater and the environment, which provides a scientific basis for environmental resources management. In this study, Shukaliefu’s classification method and Piper diagram were adopted to determine the hydrochemical types of groundwater in the Tarim Basin of Xinjiang, China. The method of “one^-vote veto” was applied to evaluate the quality of groundwater. Phreeqc software was used to calculate the saturation indices of calcite and fluorite in groundwater. By comparing groundwater quality data of 2003 and 2011, we characterized the variations in hydrochemical types and water quality types, salinization of groundwater and fluoride geochemistry of the plain area of the Tarim Basin. Results show that the primary anion in phreatic water in the plain area of the Tarim Basin changed from HCO₃ ^? to SO₄ ^2? or Cl^?. On the contrary, the primary anion in confined water changed from SO₄ ^2? or Cl^? to HCO₃ ^?. In 2003, 63.1 % of the sampling points in the study area exceeded the Class III water quality standard of China. In 2011, the proportion increased to 82.5 %. In addition, severe groundwater salinization was found at 19.7 % of the sampling points. Some of the deep groundwater samples were salinized as well. In the Aksu area at the north-west part of the Tarim Basin, F^? concentration exceeding the standard limit (1 mg/L) was found to be 55.0 % of the groundwater samples tested. Based on these findings, it is concluded that the phreatic water in the study area was severely influenced by the industrial wastewater and domestic sewage related to human activities, while the confined water was less affected. The general quality of groundwater was in an aggravation trend, and the groundwater salinization was in a severe condition in this area. The Ca²⁺–Na⁺ ionic exchange, the unsaturated fluorite and oversaturated calcite in the aquifer of the Aksu area are proposed to cause F^? enrichment in groundwater of this area.     

Assessment of groundwater quality using multivariate statistical techniques in Hashtgerd Plain, Iran

Multivariate statistical techniques, such as cluster analysis (CA), factor analysis (FA), principal component analysis (PCA), and discriminant analysis (DA), were applied for the evaluation of variations and the interpretation of a large complex groundwater quality data set of the Hashtgerd Plain. In view of this, 13 parameters were measured in groundwater of 26 different wells for two periods. Hierarchical CA grouped the 26 sampling sites into two clusters based on the similarity of groundwater quality characteristics. FA based on PCA, was applied to the data sets of the two different groups obtained from CA, and resulted in three and five effective factors explaining 79.56 and 81.57% of the total variance in groundwater quality data sets of the two clusters, respectively. The main factors obtained from FA indicate that the parameters influencing groundwater quality are mainly related to natural (dissolution of soil and rock), point source (domestic wastewater) and non-point source pollution (agriculture and orchard practices) in the sampling sites of Hashtgerd Plain. DA provided an important data reduction as it uses only three parameters, i.e., electrical conductivity (EC), magnesium (Mg²⁺) and pH, affording more than 98% correct assignations, to discriminate between the two clusters of groundwater wells in the plain. Overall, the results of this study present the effectiveness of the combined use of multivariate statistical techniques for interpretation and reduction of a large data set and for identification of sources for effective groundwater quality management.     

Assessment of groundwater quantity and quality and saltwater intrusion in the Damghan basin,Iran

This study describes the groundwater quantity and quality conditions in the Damghan aquifer in Iran. The quantitative analysis of data obtained from observation wells indicates overexploitation of groundwater during recent years, which has resulted in deterioration of water quality. The mean water level has declined about 7.4 m between years of 1966 and 2010. The hydrochemical facies of water collected from sampling wells were investigated though Piper and Chadha diagrams, and the general dominant type of water in the study area was determined as Na-Cl. The quality assessment examined the suitability of groundwater for drinking and irrigation purposes. Compared to the World Health Organization (WHO) guidelines for drinking water, all regions were found to have unpotable groundwater. Furthermore, unsuitability of groundwater for agricultural applications due to high salinity was observed through analysis of major quality indicators. The saltwater intrusion was investigated by ionic ratio analyses and was determined to be the main factor contributing to high salinity and deterioration of the groundwater quality in the Damghan basin.     

Assessment of water quality index for the groundwater in the upper Cheliff plain,Algeria

Assessment of groundwater suitability for drinking and agricultural purposes was carried out in the plain of upper Cheliff. The study area covers an area of 375 km² and lies in a semiarid climate. Groundwater is the major source for domestic and agricultural activity in this area. Groundwater samples were collected from 19 wells during dry and wet periods in 2012, and they were analyzed for major cations and anions and compared with drinking and irrigation specification standards. The concentration of the majority of chemical constituents exceeds the standards of WHO as a result of various sources of pollution. It indicates the dominance of groundwater types: Ca-Mg-Cl, and Ca-Mg-HCO₃. Suitability of groundwater for drinking was evaluated based on the water quality index; it shows more than 60% of samples have very poor quality for dry and wet periods, which means water is severely contaminated and unsuitable for drinking purpose. In terms of the irrigation usage, generally groundwater is suitable for both periods in the major part of the plain. The Mineralization processes in this area is determined by the lithology of the aquifer (exchange water-rock), by anthropogenic factors (discharges of urban sewage, use of fertilizers) and also by evaporation (semi-arid climate).     

Assessment of groundwater quality for drinking and irrigation purposes using hydrochemical studies in Nalbari district of Assam,India

The present work was carried out in Nalbari district of Assam (India) with an objective to assess the quality of groundwater and to check its suitability for drinking and irrigation purposes. Groundwater samples were collected from 50 different locations during pre- and post-monsoon seasons of 2016. Results of chemical analysis revealed that mean concentration of cations varied in the order Ca²⁺?>?Na⁺?>?Mg²⁺?>?K⁺, while for anions the order was HCO₃ ^??>?Cl^??>?SO₄^2??>?NO₃^2??>?F^? during both pre- and post-monsoon seasons. The suitability of groundwater samples for drinking purpose was assessed by comparing the results of physico-chemical analysis of groundwater with Indian Standards. Further, its suitability for irrigation purpose was assessed by evaluating several parameters like sodium adsorption ratio (SAR), sodium percentage (Na%), magnesium ratio, Kelly’s ratio and residual sodium carbonate (RSC). The SAR values obtained for all the samples were plotted against EC values in the US Salinity Laboratory diagram, and it was revealed that the most of the samples fall under water type C2-S1 indicating medium salinity and low SAR. Further, it was found that the majority of the samples belong to Ca–Mg–HCO₃ hydrochemical facies followed by Ca–Mg–Cl–SO₄, whereas only a few samples belong to Na–K–HCO₃ hydrochemical facies.     

Assessment of groundwater quality and its suitability for domestic and agricultural uses in Low-Isser plain,Boumedres, Algeria

The assessment of the suitability of groundwater for drinking and irrigation uses was carried out in the alluvial plain of Low-Isser in the north of Algeria. The plain covers an area of 533 km² and lies in a Mediterranean sub-humid climate. Groundwater is the main source for domestic uses and agricultural activities in this area. Groundwater samples were collected from 15 wells during dry and wet seasons in 2015, and they were analyzed for major cations and anions and compared with drinking and irrigation specification standards. The comparison of chemical concentration with WHO drinking water standards of 2006 shows that more than 30% of groundwater samples are unsuitable for drinking, and the majority of groundwater samples fell on the hard and very hard categories. Suitability of groundwater for drinking was also evaluated based on the water quality index (WQI). It shows more than 80% of samples have good or permissible water quality for dry and wet seasons. In terms of the irrigation usage, generally, groundwater in the study area is suitable for different uses in both seasons according to SAR, %Na, RSBC, and PI. However, water rock exchange processes and groundwater flow have been responsible for the dominated water type Ca–Mg–Cl.     

Assessment of groundwater quality for irrigation use and evolution of hydrochemical facies in the Markanda river basin,northwestern India

The Markanda river basin occupying an area of about 1547 km² is a part of the alluvial deposits of the Indo- Gangetic plain near the Himalayan foothills in the northwest India. The region is associated with active agricultural activities and makes significant contribution to the country’s agricultural products. Assessment of groundwater quality for irrigation use and hydrochemical evolution of groundwater has been studied. Hydrochemical analysis has been carried out based on concentrations of Ca²⁺, Mg²⁺, Na⁺, K⁺, Cl⁻, SO₄ ²⁻, CO₃ ²⁻ and HCO₃ ⁻. Sodium adsorption ratio (SAR), percent sodium (%Na), permeability index (PI) and Trilinear diagram have been studied to evaluate suitability of irrigation use. Hydrochemical evolution has been analyzed based on the Chebotarev sequence and expanded Durov diagram. SAR, %Na and PI results indicate that the groundwater in the basin is suitable for irrigation use. Analysis on Trilinear diagram reveals that hydrochemical facies are dominated by HCO₃ ⁻- Ca²⁺- Mg²⁺ facies indicating that the groundwater is associated with recharge waters percolating through sandstone and limestone rocks which are exposed in the northern part of the basin. Studies based on Chebotarev anion sequence and expanded Durov diagram indicate that the evolution of groundwater belongs to initial to intermediate stage indicating fresh water quality. Thus, the present work reveals that groundwater in the Markanda basin is of good quality and is suitable for all uses including interbasin water transfer in the region.     

吉林省松辽平原东部高平原白垩系地下水水化学特征

吉林省松辽平原东部高平原第四系孔隙地下水由于缺少良好的含水层而比较贫乏。白垩系基岩孔隙裂隙水就成了本区地下水主要的供水开采层。在简要阐述白垩系区域水文地质条件的基础上，分析白垩系地下水水化学特征及其水化学成分在水平和垂直方向上的变化规律，从水质方面为地下水合理开发提供科学依据。     

Land subsidence due to groundwater withdrawal in Arak plain,Markazi province,Iran

With current trends of groundwater exploitation, the plains of Iran have been facing numerous problems, where subsidence is considered as the foremost obstacle. In the present study, the principle aim was to analyze the level of groundwater and induced subsidence effects in different regions of Arak plain from 2002 to 2008. Arak plain located in Meyghan Lake basin is subjected to subsidence process as a result of the declining groundwater levels. Monthly variations of groundwater levels were plotted using ArcGIS software. The results indicated declining water levels especially in Meyghan Lake than the Arak plains, resulting up to 36 m of drop in the groundwater levels of marginal areas in the plains during these years.     

江苏南通地下水补给源、水化学特征及形成机理

在地下水的大规模开采条件下,江苏沿海一带,特别是南通许多地区的地下水一度出现咸化趋势,对区域水资源及环境产生了极大的影响,已成为制约生态环境建设和经济社会发展的重要因素.为查明地下水的补给来源、水化学特征和矿化度增高的机理,对南通地区深浅层地下水开展了野外调查取样.通过对各种水化学参数的讨论分析,系统地研究了该区地下水...     

Groundwater quality assessment in southern parts of Tehran plain,Iran

The hydrochemical characteristics of groundwater in the southern parts of Tehran Province are considered. Twenty-three sampling stations were selected and major anions/cations, electrical conductivity and pH were detected. Sulfate and chloride were found as major anions, while no specific dominant cation was determined. More than half of the samples were found to be unsuitable for drinking purposes, due to high concentrations of anions/cations. Regarding agricultural use, almost all samples were classified as having high-risk levels of salinity, while for alkali hazard considerable risks were observed in most cases. Generally, an increasing trend of salinity is observed from northwest to southeast of the study area. Such increase may be justified by the adjacency of the Iran central desert and salt lake to the southern boundaries of the study area. Extended use of sulfate-containing fertilizers may also play a key role in justifying the high sulfate concentration in comparison to other anions.     

Water quality assessment and hydrochemical characteristics of groundwater on the aspect of metals in an old town,Foshan, south China

The present study is aimed at assessing the water quality and discussing the hydrochemical characteristics and seasonal variation of shallow groundwater on the aspect of metals in the eastern Chancheng district of Foshan city, south China. Multivariate analytical methods such as principal components analysis (PCA) and hierarchical cluster analysis (HCA) were used in this study. The results show that 45% of groundwater in the east-central of study area is not suitable for drinking purpose due to high concentrations of Fe, Pb and Mn. The mean concentrations of Fe, Hg, Cu, Pb, and Mn in dry season are higher than that in wet season. On the contrary, the mean concentrations of Cd, Co, Zn, Ba, Cr, Mo, Ni and Al in wet season are higher than that in dry season. PCA results show that four PCs are responsible for the 78.6% of the total hydrochemical variables in groundwater. Three groups were generated from HCA method. Group 1 reflects the characteristic of wet season and the low ion exchange capacity; group 2 is mainly influenced by the dry season. Reducing environment and high ion exchange capacity are responsible for group 3. The results are useful in addressing future measures in groundwater resource management for local government.     

Numerical simulation of groundwater flow and contamination transport in Nahavand plain aquifer,west of Iran

Numerical simulation of groundwater flow used for the estimation of hydraulic and hydrologic parameters which is an important tool for the management of aquifers. This study presents the results of a mathematical model developed for the simulation of groundwater flow in Nahavand plain aquifer in the southwest Hamadan province. For this purpose Groundwater Modeling Software (GMS) was used which supports the MODFLOW-2000 code. After gathering required data such as the hydrological, hydrogeological and topography maps, a 3D hydrogeological model of plain was constructed with borehole and surface elevation data. Then MODFLOW was used for simulation of flow. After initial simulation of the flow, the model was calibrated in steady state with trial-and-error and parameter estimation methods the observed head of groundwater table monitoring data of 1997. Results of calibration show that error between observed head and computed head is in allowable range. Also results of computed head with model show that groundwater flow is in the direction of the dominate slope (southeast to northwest). Finally MODPATH code which simulates advective transport of particles was used for estimation of flow path and source of contaminants.     

Potential impacts of climate change on groundwater levels on the Kerdi-Shirazi plain,Iran

It is important to predict how groundwater levels in an aquifer will respond to various climate change scenarios to effectively plan for how groundwater resources will be used in the future. Due to the overuse of groundwater resources and the multi-year drought in the Kerdi-Shirazi plain in Iran, some land subsidence and a drop in groundwater levels has taken place, and without active management, further degradation of the groundwater resource is possible under predicted future climate change scenarios in the country. To determine the potential impacts of climate change on groundwater levels in the region, the groundwater model GMS was coupled with the atmospheric circulation model HADCM3 using scenarios A1B, A2 and B1 for the period 2016–2030. The results of the climate modelling suggest that the Kerdi-Shirazi plain will experience an increase in minimum temperature and maximum temperature of, respectively, between 0.03 and 0.47, and 0.32–0.45 °C for this time period. The results of the groundwater modelling suggest that water levels on the Kerdi-Shirazi plain will continue to decline over the forecast period with decreases of 34.51, 36.57 and 33.58 m being predicted, respectively, for climate scenarios A1B, A2 and B1. Consequently, groundwater resources in the Kerdi-Shirazi plain will urgently need active management to minimize the effects of ongoing water level decline and to prevent saltwater intrusion and desertification in the region.     

宿州市城区地下水化学特征及成因机制研究

为深入研究宿州市城区地下水化学特征及其控制因素,在调查采样的基础上,综合运用数理统计、相关性分析、Piper三线图、Gibbs图和离子比例系数等方法对水样测试结果进行分析研究。结果表明：① 浅层地下水优势阳离子为Ca2+,中深层地下水中Na+为优势阳离子,二者优势阴离子均为HCO3-。浅层地下水溶解性固体总量的质量浓度（TDS）均值为790. 65 mg/L,有3组为微咸水,其余均为淡水;中深层地下水TDS均值为585. 67 mg/L,均为淡水。② 浅层地下水化学类型复杂,以HCO3-—Ca2+·Mg2+、HCO3-—Na+·Ca2+·Mg2+型为主,其次为HCO3-—Na+·Mg2+型;中深层地下水化学类型相对简单,以HCO3-—Na+·Ca2+·Mg2+型为主。③地下水水化学特征受岩石溶滤作用、阳离子交替吸附作用和人类活动的共同影响,水化学成分多数来自于硅酸盐岩和碳酸盐岩矿物的溶解。浅层地下水受人类活动影响较大,而中深层地下水受其影响不明显。     

广西钦州港地区地下水水化学特征及形成作用

为查明钦州港地区地下水水化学特征及形成作用,本文分枯水期、丰水期采集了钦州港地区68组浅层地下水样,测试Na+、Ca2+、Mg2+、HCO3-、Cl-、SO42-和总溶解固体(TDS)等化学指标并进行了相关分析。结果表明:①季节变化对地下水水化学空间变异性影响较小;②地下水水化学类型以Ca-Mg-SO4-Cl型为主,主要从Ca-Mg-HCO3型和Na-Cl-SO4型向Ca-Mg-SO4-Cl型演化;③地下水水化学成分主要通过溶滤作用、阳离子交换吸附作用、蒸发浓缩等形成,人类活动对地下水的影响越来越重要,导致了地下水化学成分不断发展变化。     

Correlation of lineaments and groundwater quality in Dasht-e-Arjan Fars,SW of Iran

The NE-oriented Dasht-e-Arjan graben is located 65 km west of Shiraz and has resulted from the active Kare-e-Bas fault segmentations. This extensional graben bounded by two fault system east-Arjan and west-Arjan to the Shahneshin and Salamati anticline. In these study using Landsat 7 ETM images with resolution 2.5 m and directional filtering in the four azimuths and semi-automatic technique for linear structure in the study area. Using the obtained data from extracted lineaments, the rose diagrams of the main strike lineaments are well confirm with field measurements of faults with N56° ± 4°E direction. The structural lineaments of the study area show that the Dasht-e-Arjan area is underlain by the limestone, sandstone, and marl. LANDSAT imagery of the area has been analyzed and interpreted in order to determine the lineament and groundwater quality across the area. The fracture is structurally controlled and mostly influences both the groundwater and surface water pollution and flow directions in the Dasht-e-Arjan. Using visual interpretation, determining the lineaments on the satellite image is very difficult and subjective, and it requires an experienced interpreter. In this study, the lineament analysis is undertaken to examine the orientation of the lineament, the relationship between lineaments and tectonic features and groundwater quality. Lineament density maps show that the lineament density is high around areas. Areas having high lineament density represent areas with relatively high groundwater pollution. Field observations agreed with the results from the analysis of the imagery.