首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
The present study deals with the hydrogeochemistry and water quality of shallow aquifers in two important river basins—the Ithikkara and Kallada river basins—draining the south western flanks of Western Ghats in Kerala, South West India. Well water samples were collected from 20 dug wells with a depth range of 1 m below ground level (mbgl) to 18.2 mbgl during pre-monsoon, monsoon, and post-monsoon seasons of the year 2011–2012. These samples were analyzed for various physico-chemical parameters following standard methods and were evaluated for their interrelations and drinking water suitability. The pH of the water samples shows wide variation from highly acidic to highly alkaline water. About 80% of pre-monsoon samples recorded Fe2+ concentration above the permissible limit of drinking water standard. Water Quality Index (WQI) shows that majority of the well water samples fall in the category of excellent–good for drinking purpose. The results of the irrigation suitability assessment using the procedures like Percent Sodium, Sodium Absorption Ratio, Residual Sodium Carbonate, Kelly Index, Permeability Index, and Magnesium Hazard reveal that the well waters of the study area are fit for irrigation purpose. Na+/Cl? ratio reflects the release of sodium to water due to silicate weathering. The samples have a Ca2+/Mg2+ ratio equal or greater than 2 indicating the effect of silicate minerals in contributing Ca2+ and Mg2+ ions to the well water. The saturation indices reveal that groundwater is supersaturated with SiO2. Among the causative factors that determine the hydrochemical quality of well water samples, silicate weathering plays a pivotal role with significant input of ions from anthropogenic sources.  相似文献   

2.
The purpose of this research is to evaluate the groundwater quality in Dindugal district of Tamil Nadu based on the water quality index by geographic information system (GIS) and statistical analysis. This area consists of 80 functional tanneries around Dindigul town with a capacity to process about 200 Mt of hides and skins as leather. In 13 villages, as many as 1090 houses were damaged by tannery contamination. A total of 66 groundwater samples were collected to identify the geochemical sources and contamination. The order of major cations is Na > Ca > Mg > K, while that of anions is Cl > SO4 > HCO3 > F > PO4. CaCl2, MgCl2, and (CaHCO3)2 types suggested that the mixing of high-salinity water was caused by irrigation return flow, domestic wastewater, and septic tank effluents, with existing water followed by ion exchange reactions. Moreover, Gibbs plots indicated that groundwater contamination was derived from the weathering of granitic gneisses as well as the leaching of evaporated and crystallized ions from agricultural and industrial effluents. The water quality index (WQI) exhibited 8 % of the groundwater samples were not suitable for drinking purpose. The GIS maps showed that the poor water quality decreased toward the southern part of the study area. WQI of TDS, fluoride, sodium, potassium, and bicarbonate were high in groundwater. Multivariate statistical analyses (principal component analysis (PCA), factor analysis (FA)) suggested that the groundwater chemistry was changed by the weathering of source rocks ion exchange and leaching of inorganic components and addition from anthropogenic effluents. Finally, it is thought that the monitoring and assessment works are very useful to understand the degree and sources of groundwater contamination.  相似文献   

3.
Seasonal variation of ground water in Nayagarh district, Odisha is determined by analysing both pre and post monsoon water samples. The high fluoride content is an endemic problem in the area and special attention was attached to the point. The chemical compositions of the ground water of the area are dominated by CaCl, NaCl and mixed CaMgCl types in pre-monsoon and CaHCO3-mixed CaMgCl type in post-monsoon. This is largely due to chemical weathering of Eastern Ghats Mobile Belt rock types. Increasing alkalinity vis-a-vis F concentration in pre-monsoon is associated with sodium-bicarbonate water types having high pH (>7) and low calcium and magnesium contents. The percentage of total high fluoride containing water samples is nearly double in pre-monsoon than in post-monsoon. During both the seasons, pH values indicate mildly alkaline to weakly acidic nature of the water samples. Fluoride concentration has good correlation with pH in pre-monsoon whereas in post-monsoon it shows good correlation with Fe. Facies analysis indicates that water is becoming predominantly Ca-Na cation and Cl-SO4-HCO3 anion type in premonsoon than Ca-Mg type and HCO3-Cl-SO4 type in post-monsoon. The seasonal variations in concentrations of anthropogenic components demonstrate that the groundwater system is very less liable to pollution by human activities.  相似文献   

4.
Water quality assessment study of the three major rivers within the Cross River Basin have been carried out using cross plots, ionic ratio, correlation analysis, factor analysis and water quality index (WQI) based on the World Health Organization and world average data guidelines. The primary aim was to determine their suitability for domestic and irrigation uses, while the secondary aim was to determine the sources of the ions in the river water. The results showed that the water samples from the Cross River estuary generally had elevated values of dissolved ions as compared to the Calabar and Great Kwa Rivers. Cross plots, ionic ratios, correlation and factor analyses showed tidal influence, silicate weathering, nitrate pollution and dissolution of carbonate minerals from soil CO2 as the origin of the variables. Chemical indices including sodium adsorption ratio and residual sodium carbonate indicate that the river water of the study area are suitable for domestic and irrigation, while sodium percentage (Na %) indicate unsuitability for irrigation applications. The WQI values on the average indicate water of very poor to excellent quality. Generally in terms of quality for the different rivers, the Great Kwa River is best as compared to the Calabar River and Cross River estuary for domestic and irrigation purposes.  相似文献   

5.
Groundwater is a vital source of water for industrial, domestic and agricultural activities in Tuticorin city due to lack of surface water resources; groundwater quality and its suitability for drinking usage were evaluated. A total of 72 groundwater samples were collected from open wells and boreholes during pre and post-monsoon period. Samples were analyzed for physico-chemical properties, major cation and major anions in the laboratory using the standard methods given by the American Public Health Association. The geographic information system-based spatial distribution map of different major elements has been prepared using ArcGIS 9.2. These maps are classified as desirable, maximum permissible and the values that exceed maximum permissible limit are termed as not permissible prescribed by the WHO (2004). From the Piper plot, which gives the cation chemistry, the concentration of the alkalies (Na+ and K+) exceeds the alkaline earths (Ca2+ and Mg2+) and those of strong acids exceeds weak acids. In the case of anions, during the two periods strong acid shows dominance over weak acid and HCO3 ? and Cl? have influences almost equal to Na+, which indicate the saltwater intrusion into the freshwater aquifer of the study area. A Canadian Council of Ministers for the Environment Water Quality Index (CCME WQI) map was also generated with the GIS technique to better understand the water portability over space. The categories of water quality evaluated by CCME WQI values of major part of the study area fall under fair category during PRM and good category during the POM period. The CCME WQI is a very useful and an efficient tool to summarize and to report on the monitoring data to the decision makers in order to understand the status of the groundwater quality. Finally, the study concludes that the groundwater quality is impaired by man-made activities, and proper management plan is necessary to protect valuable groundwater resources in Tuticorin city.  相似文献   

6.
Water samples collected from the six reservoirs of Damodar River basin in pre- and post-monsoon, have been analysed, to study the major ion chemistry and the weathering and geochemical processes controlling the water composition. Ca, Na and HCO3 dominate the chemical composition of the reservoir water. The seasonal data shows a minimum concentration of most of the ions in post-monsoon and a maximum concentration in pre-monsoon seasons, reflecting the concentrating effects due to elevated temperature and increased evaporation during the low water level period of the pre-monsoon season. Water chemistry of the reservoirs strongly reflects the dominance of continental weathering aided by atmospheric and anthropogenic activities in the catchment area. Higher concentration of SO4 and TDS in Panchet, Durgapur and Tenughat reservoirs indicate mining and anthropogenic impact on water quality. The high contribution of (Ca+Mg) to the total cations, high concentration of dissolved silica, relatively high (Na+K)/TZ+ ratio (0.3) and low equivalent ratio of (Ca+Mg)/(Na+K) suggests combined influence of carbonate and silicate weathering. Kaolinite is the possible mineral that is in equilibrium with the water, implying that the chemistry of reservoir water favours kaolinite formation. The calculated values of SAR, RSC and sodium percentage indicate the ‘excellent to good quality’ of water for irrigation uses.  相似文献   

7.
The study reported here is a part of an attempt to establish a comprehensive hydrochemical and isotopic baseline for a tropical wetland system as background data for a range of applications. Surface water samples of Vembanad Lake were collected from 20 stations in three seasons during the period 2007–2009. The analytical results were subjected to different chemical classification techniques to understand processes affecting the chemical concentration of waters. The Piper diagram classified the water samples as 100% alkali group in pre-monsoon followed by 15% in monsoon and 85% in post-monsoon, and for anions 100% samples were of strong acids followed by 90% in monsoon and 100% in post-monsoon season. The plot to decipher the mechanism controlling water chemistry placed the Vembanad Lake in the region of precipitation and rock dominance in the monsoon season and in the field of saline water dominance in pre-monsoon and post-monsoon season. The positive values for the chloro-alkaline indices in pre and post-monsoon season promoted cation exchange in the system. The stable isotopes of water samples ranged from ?20.21 to +17.0‰ and ?5.6 to +3.34‰ for δ 2H and δ 18O, respectively. The most depleted δ values observed in the monsoon are due to the amount effect. The high enrichment observed in pre-monsoon is primarily due to evaporation and salinity mixing. The variation of isotopes in the whole system point toward the fact that salinity mixing can be indicated by the δ 18O variation and δ 2H indicates the evaporation effect. The plot of δ 18O with chloride concentration showed precipitation dominance in the monsoon season, mixing of saline water and evaporation in pre-monsoon season, whereas the post-monsoon samples plot in both fresh and saline region.  相似文献   

8.
Fifty groundwater samples were collected from Al-Hasa to analyze the pH, electrical conductivity (EC, dS m?1), total dissolved solids (TDS), major anions (HCO3?, CO32?, Cl?, SO42?, and NO3?), major cations (Ca2+, Mg2+, Na+, and K+), and total hardness. The analyzed data plotted in the Piper, Gibbs, and Durov diagrams, and water quality index (WQI) were calculated to evaluate the groundwater geochemistry and its water quality. The results reveal that most of the investigated samples are Ca2+, Mg2+, SO42?, Cl? and Na+, and HCO3? water types using the Piper diagram. Na+?>?Ca2+?>?Mg2+ are the dominant cations, while Cl??>?HCO3??>?SO42??>?CO32? are the dominant anions. Sodium adsorption ratio (SAR) values varied from 0.79 to 10; however, the Kelly ratio (KR) ranged between 0.1 and 2.2. The permeability index (PI) showed that well water is suitable for irrigation purposes with 75% or more of maximum permeability. The US salinity diagram revealed that the water quality classes of studied waters were CIII-SI, CIII-SII, and CIV-SII, representing height hazards of salinity and medium- to low-sodium hazard. The water quality index (WQI) results indicated that total dissolved solids are out of the drinking water standard limits in Saudi Arabia. The WQI revealed that 38% of the studied wells were considered as poor water (class III), 52% are found as very poor water class (IV), and 10% are unsuitable water for drinking class (V).  相似文献   

9.
Groundwater is a precious resource for humankind not only in Nepal but also across the globe due to its diverse functions. A total of 48 groundwater samples were collected from three villages of Nawalparasi district, Nepal, during pre-monsoon and monsoon to estimate the overall groundwater quality and to identify the sources of contamination with emphasis on arsenic (As). The average concentrations of all tested groundwater quality parameters (temp., pH, EC, ORP, Ca2+, Mg2+, Na+, K+, Cl?, F?,SO4 2?, PO4 3?, HCO3 ?, NO3 ?, Cu, Ni, Mn, Cd, Pb, Fe, Zn, Cr, and As) were well within permissible limits of WHO for drinking water, except for Ni, Cd, Pb, Cr, and As. Concentration of As ranged from 60 to 3,100 μg L?1 and 155 to 1,338 μg L?1 in pre-monsoon and monsoon, respectively. The Piper diagram of the groundwater chemistry showed groundwater of Nawalparasi belongs to Ca–Mg–HCO3 and Mg–HCO3 water type with HCO3 ? as dominant ions. As content in the study area was negatively correlated with Fe in pre-monsoon, while it was positively correlated in monsoon. Furthermore, As was negatively correlated with oxidation reduction potential suggesting reducing condition of groundwater. Principal component analysis revealed seven major factors that explained 81.996 and 83.763 % of total variance in water quality in pre-monsoon and monsoon, respectively. The variance of water quality was related mainly with the degree of water–rock interaction, mineralization, and anthropogenic inputs.  相似文献   

10.
Adverse effect of rapid industrialization on groundwater quality and quantity is widely known problem especially in developing countries. Tirupur, which is situated on the bank of Noyyal River in India, is known for intensive textile processing activities. As groundwater is the main water source for drinking water, there is an urgency to assess the groundwater quality. Twenty groundwater samples were collected for each post and pre-monsoon sampling during August 2009 and March 2010, respectively. Chemical and statistical analysis along with numerical modelling has been performed to assess the current status. The hydro-geochemical study revealed that the dominance of Mg–Cl and Na–HCO3 groundwater type in the upstream region Tirupur industrial hub of Noyyal River basin. Na–Cl groundwater type was found increasing in industrial hub (Kasipalayam) and downstream of the industrial hub (Anaipalayam) sites. The dominance of Na–Cl type of water is mainly due to the impact of salts like NaCl, Na2SO4, etc. used in textile processing, which after discharge, percolate and accumulate in the aquifers. Seasonal groundwater quality of Tirupur region as a whole showed the dominance of Ca–HCO3 ?, Na–HCO3 ? and Na–Cl water types. PHREEQC model output indicates that nearly all the groundwater samples were oversaturated with respect to calcite and dolomite and undersaturated with respect to gypsum and halite. The results obtained in this study were then compared with groundwater quality of the Noyyal River basin for the year 2008–2009. Among the two sites, Kasipalayam was found to be most contaminated due to incessant industrial discharge. But with the advent of new treatment technologies like CETPs having zero liquid discharge system and MBR, there has been slight decline in the concentration of different physicochemical parameters from 2002–2003 to 2008–2009. This study not only makes situation alarming but also calls for immediate attention for sustainable management of water resources.  相似文献   

11.
Conventional graphical and statistical methods were used with water quality indices to characterize the hydrochemistry of groundwater from the northern part of the Volta region of Ghana. The objective was to determine the processes that affect the hydrochemistry and the variation of these processes in space among the three main geological terrains: the Buem formation, Voltaian System and the Togo series that underlie the area, and to determine the suitability of groundwater from the area for drinking purposes. The Q-mode cluster analysis reveals three main water groups. The groups established from the Q-mode HCA appear to indicate different degrees of weathering which could further indicate varying levels of fracturing aquifer hydraulic properties. R-mode HCA and factor analysis (using varimax rotation and Kaiser Criterion) were then applied to determine the significant sources of variation in the hydrochemistry. This study finds that groundwater hydrochemistry in the area is controlled by the weathering of silicate and carbonate minerals, as well as the chemistry of infiltrating precipitation. Mineral activity diagrams for the CaO–Na2O–Al2O3–SiO2–H2O and CaO–MgO–Al2O3–SiO2–H2O systems plotted for the area indicate stability in the smectite field and attribute hydrochemistry to the weathering of silicate minerals. Silicate mineral weathering and the effects of precipitation appear to be pervasive among all the three main geological terrains, whereas carbonate weathering is localized among the Voltaian aquifers. Cation exchange does not appear to play a significant role in the hydrochemistry but mild Water quality indices (WQI) were calculated for the samples using the concentrations of Na+, Ca2+, Mg2+, Cl−, NO3 −, F−, and EC at the various sample locations. The WQI values indicate that groundwater from the study area is of excellent quality for drinking purposes. WQI values from groundwater samples are averagely higher than samples taken from surface water sources in the area. This implies that geology has had an impact on the WQI of groundwater in the area.  相似文献   

12.
An effort has been made to comprehend the groundwater quality of Raipur city for drinking purpose utilizing Water Quality Index (WQI) and Geographic Information System (GIS) techniques. In this study thirty four groundwater samples were collected during May, 2015. Standard methods has been adopted in groundwater sampling which are prescribed by the American Public Health Association (APHA, 1995). Eight water quality parameters have been considered to ascertained water quality index viz. pH, chloride, fluoride, calcium, magnesium, alkalinity, hardness and nitrate. The Bureau of Indian Standard (BIS, 2009) has been considered to assess the suitability of groundwater for drinking purposes and for the calculation of WQI. This study reveals that 76% area is falling under excellent, very good and good category and 24% area is falling under poor, very poor and unfit category as per the WQI classification. The predicted accuracy of the obtained result is around 97.05% reflecting capability of adopted techniques. Anthropogenic activities are influencing the groundwater quality of the study area. The present study is helpful in proper planning and management of available water resource for drinking purpose.  相似文献   

13.
Groundwater is the most important natural resource used for drinking by many people around the world, especially in rural areas. In Tunisia, since the quantity and the quality of water available for different uses is variable from one place to another, groundwater quality in El Khairat deep aquifer was evaluated for its suitability for drinking purposes. To this end, an attempt has been made for the first time in order to determine spatial distribution of groundwater quality parameters and to identify places with the best quality for drinking within the study area based on: (1) an integrated analysis of physical?Cchemical parameters, (2) use of Geographical Information System, and (3) Water Quality Index (WQI) calculation. The physical?Cchemical results were compared with the World Health Organization (WHO) standards for drinking and public health, in order to have an overview of the present groundwater quality. According to the overall assessment of the basin, almost all the parameters analyzed are above the desirable limits of WHO. Using GIS contouring methods with Arcview 3.2a, spatial distribution maps of pH, TDS, EC, TH, Cl, HCO3, SO4, NO3, Ca, Mg, Na, and K have been created. The spatial analysis of groundwater quality patterns of the study area shows that the TDS value increases from north-west to south-east following the general trend of the Khairat aquifer flow direction. The spatial distribution map of TH shows that a majority of the groundwater samples falls in the very hard category. WQI was used to assess the suitability of groundwater from the study area for human consumption. From the WQI assessment, over 82% of the water samples fall within the ??Poor?? and ??Very poor?? categories, suggesting that groundwater from the south-eastern of the El Khairat deep aquifer is unsuitable for drinking purposes.  相似文献   

14.
This research aimed to investigate the long-term spatiotemporal changes of surface water quality of the Maroon River by implementing Water Quality Index (WQI) and multivariate statistical analyses such as non-metric multidimensional scaling and cluster analyses, as complementary tools to investigate spatial variations in water quality parameters and also delineate areas in terms of water quality conditions in the period under study. The other purposes of this study were to evaluate the physicochemical properties of the Maroon River water and assess the effects of each water quality parameter on the WQI values. Relationship between quality scale of hydrochemical parameters and the resulting WQI scores was determined employing linear regression analysis. Moreover, the suitability of water quality was evaluated for irrigation purposes using conventional indices, electrical conductivity (EC), sodium adsorption ratio (SAR), and percent sodium (Na%). The monitoring stations were placed in high and very high categories according to the assessment of irrigation water quality with EC. Considering WQI, the upper (S1, S2, and S4) and lower (S3, S5, and S6) monitoring stations of the Maroon River distributed in category C3 (high salinity) and C4–C5 (very high salinity), respectively. The findings of WQI presented an increasing trend from upstream toward downstream in the Maroon River. The findings of the linear regression analysis showed no significant correlation between WQI scores with pH and SO4 2? concentrations even though the relationship is weak. These results suggest that pH and SO4 2? concentrations could be the secondary driving parameters behind the variations in WQI scores. It can be inferred that the Maroon River water is appropriate for irrigation based on Na% and SAR. However, it also exhibits high EC. Therefore, for mitigating the adverse impacts of polluted water authors recommend multidimensional management practices such as transferable discharge permit programs in the study area.  相似文献   

15.
The present study aims to discuss the hydrogeochemical processes in the Aosta Valley region and assess the quality of its groundwater for suitability of drinking and irrigation purposes. One hundred twenty-two samples were collected from the Aosta Valley region in the years 2007 and 2008 (61 per year), and analysed for pH, electrical conductivity, total dissolved solids (TDS), total hardness, major cations and anions. The pH of the samples in both years indicated a near-neutral to alkaline nature of the groundwater. The cation and anion chemistry showed the general ionic abundance as: Ca2+ > Mg2+ > Na+ > K+ and HCO3 ?>SO4 2?>Cl?>NO3 ?>F? in both years. Ca2+-Mg2+-HCO3 ? and Ca2+-Mg2+-Cl?-SO4 2? were the dominant hydrogeochemical facies. The computed saturation indices demonstrated that the groundwater was supersaturated with respect to dolomite and calcite in both years. The groundwater chemistry of the study area was mainly controlled by the dissolution of carbonate, sulphate and silicate minerals, as well as ion exchange processes. A comparison of the groundwater quality in relation to drinking water standards showed that most of the water samples were suitable for drinking and domestic uses. The computed water quality index (WQI) values of the study area groundwater ranged from 24 to 84 in the year 2007 and from 22 to 82 in the year 2008, and all the location fell under the Excellent to Good category. Quality assessment for irrigation uses revealed that the groundwater was good to permissible quality for irrigation; however, locally higher salinity, residual sodium carbonate (RSC) and magnesium hazard (MH) restricted its suitability for irrigation at a few sites. These results will be useful in implementing future measures in groundwater resource management at regional and national level.  相似文献   

16.
In the management of water resources, quality of water is just as important as its quantity. In order to know the quality and/or suitability of groundwater for domestic and irrigation in upper Gunjanaeru River basin, 51 water samples in post-monsoon and 46 in pre-monsoon seasons were collected and analyzed for various parameters. Geological units are alluvium, shale and quartzite. Based on the analytical results, chemical indices like percent sodium, sodium adsorption ratio, residual sodium carbonate, permeability index (PI) and chloroalkaline indices were calculated. The pre-monsoon waters have low sodium hazard as compared to post-monsoon season. Residual sodium carbonate values revealed that one sample is not suitable in both the seasons for irrigation purposes due the occurrence of alkaline white patches and low permeability of the soil. PI values of both seasons revealed that the ground waters are generally suitable for irrigation. The positive values of Chloroalkaline indices in post-monsoon (80%) and in pre-monsoon (59%) water samples indicate absence of base-exchange reaction (chloroalkaline disequilibrium), and remaining samples of negative values of the ratios indicate base-exchange reaction (chloroalkaline equilibrium). Chadha rectangular diagram for geochemical classification and hydrochemical processes of groundwater for both seasons indicates that most of waters are Ca–Mg–HCO3 type. Assessment of water samples from various methods indicated that majority of the water samples in both seasons are suitable for different purposes except at Yanadipalle (sample no. 8) that requires precautionary measures. The overall quality of groundwater in post-monsoon season in all chemical constituents is on the higher side due to dissolution of surface pollutants during the infiltration and percolation of rainwater and at few places due to agricultural and domestic activities.  相似文献   

17.
Assessment of groundwater quality in and around Vedaraniyam,South India   总被引：1，自引：1，他引：0  
Groundwater from 47 wells were analyzed on the basis of hydrochemical parameters like pH, electric conductivity, total dissolved solids, Ca2+, Mg2+, Na+, K+, Cl?, CO3 2?, HCO3 ?, NO3 ?, PO4 3? and F? in the Cauvery delta of Vedaraniyam coast. Further, water quality index (WQI), sodium percentage (Na %), sodium absorption ratio, residual sodium carbonate, permeability index and Kelley’s ratio were evaluated to understand the suitability of water for drinking and irrigation purposes. The result shows significant difference in the quality of water along the coastal stretch. The order of dominance of major ions is as follows: Na+ ≥ Mg2+ ≥ Ca2+ ≥ K+ and Cl? ≥ HCO3 ? ≥ CO3 2? ≥ PO4 3? ≥ F?. Na/Cl, Cl/HCO3 ratio and Revelle index confirmed that 60–70 % of the samples were affected by saline water intrusion. WQI showed that 36 % of the samples were good for drinking and the remaining were poor and unsuitable for drinking purpose. The degradation of groundwater quality was found to be mainly due to over-exploitation, brackish aquaculture practice, fertilizer input from agriculture and also due to domestic sewage.  相似文献   

18.
An attempt has been made to evaluate the water quality in the fast-growing coastal area of South Chennai. Groundwater samples were collected from selected locations and analyzed for major physico-chemical parameters. Experimental results show that the water has alkaline with pH varying from 7.2 to 8.2. Concentrations of Na and Cl were positively correlated with EC and elevated levels of these parameters near the coastal region, especially in the northern end of the study area, indicating the influence of seawater intrusion. Piper diagram identified Na–Cl as the dominant type of water in most of the samples. The presence of Ca–Cl facies in the groundwater suggests the possible ion exchange (Na with Ca) reaction in the aquifer. Molar ratios of Cl/HCO3 and Mg/Ca showed a higher value (>1) in many samples, which confirmed the influence of seawater intrusion on water quality. The Water Quality Index (WQI) of the study area ranged between 8 and 116, the highest recorded being at Thiruvanmiyur and the lowest at Muttukkadu. However, total hardness values show that 64% of the samples were hard or very hard in nature. The results of SAR, Na%, and PI show that majority of the samples are suitable for irrigation purposes. A comparison of spatial distribution maps of water quality parameters with those of WQI shows that groundwater quality has highly deteriorated in the Thiruvanmiyur region, located on the northeast part of the study area. Good-quality water is found at the southeast part of the study area, namely, Muttukkadu. This study indicates that urbanization and seawater intrusion have heavily affected the groundwater quality of South Chennai coastal area.  相似文献   

19.
Groundwater is the most important natural resource used for drinking by many people around the world, especially in arid and semi-arid areas. The resource cannot be optimally used and sustained unless the quality of groundwater is assessed. Saveh-Nobaran aquifer in Iran is the most important groundwater aquiferous system in the region which is considered a major source for drinking and irrigation. The main objective of this study is to understand the groundwater quality status of Saveh-Nobaran aquifer, followed by attempts to investigate the spatial distribution of groundwater quality parameters to identify places with the best quality for drinking consume within the study area. For this purpose, a set of original data, as yet unpublished, is presented. This paper provides an important contribution for understanding relationship between land use and groundwater quality, and also groundwater depth and groundwater quality. This goal has been achieved with the combined use of the Water Quality Index (WQI) and a geographical information system (GIS). A total of 58 groundwater samples were collected and analyzed for major cations and anions. Spatial distribution maps of pH, TDS, EC, TH, Cl, HCO, SO4, Ca, Mg, Na and K have been created using the kriging method in a GIS environment. From the WQI assessment, over 65 % of the water samples fall within the ‘‘Poor’’, ‘‘Very poor’’ and “unsuitable for drinking” categories, suggesting that groundwater from the center and north-east of the Saveh-Nobaran aquifer is unsuitable for drinking purposes. This research and its results have shown the great combination use of GIS and WQI in assessing groundwater quality. Having a clear view of the geographic areas of groundwater quality, decision makers can plan better for the operation and maintenance of groundwater resources.  相似文献   

20.
Groundwater samples were collected from Mettur taluk of Salem district, Tamilnadu, India for two different seasons (pre-monsoon and post-monsoon) and analyzed for fluoride ion along with other chemical parameters. The major litho units of the study area are Charnockites, peninsular gneiss, and calc gneiss of meta-sedimentary group. The fluoride concentration ranges from 0.1 to 2.8?mg/L and 0.4 to 4.0?mg/L during pre-monsoon (PRM) and post-monsoon (POM) seasons, respectively. Results showed that collected water samples were contaminated by the presence of fluoride ion. During PRM and POM, 21% and 56% of samples recorded higher fluoride when compared with Indian Drinking Water Standard (1?mg/L) and (9% and 35%) of samples recorded higher fluoride when compared with World Health Organization tolerance limit (1.5?mg/L). The ratio of Na/Ca indicates high sodium content in groundwater enhances the dissolution of fluoride at higher pH. Hydrogeochemical facies indicates water-rock interaction as main source for high fluoride in groundwater. A positive correlation between pH, Mg, and F indicates high alkaline nature of water promotes fluoride leaching from source rocks into ground water. Factor analysis indicates hydro-geochemical processes like weathering, ion exchange, and anthropogenic contributes to groundwater chemistry. The saturation index indicates dissolution and precipitation contributes fluoride dissolution along with mixing.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号