S. Venkatramanan

Influence of hydrogeochemical processes and assessment of suitability for groundwater uses in Busan City, Korea

This study was carried out to understand the hydrogeochemical processes of groundwater quality and groundwater use in the Suyeong District of Busan city, Korea. Groundwater samples were collected from 40 wells in February, 2010. The abundance of major cations concentration in groundwater is Na+xa0>xa0Ca2+xa0>xa0Mg2+>xa0K+, while that of anions is Cl−xa0>xa0HCO3−xa0>xa0SO42−xa0>xa0NO3−xa0>xa0F−. According to hydrogeochemical facies, Ca (HCO3)2, Ca Cl2 and NaCl are the dominant groundwater types in this study area. Mechanism controlling the water chemistry (Gibbs) indicates that most of groundwater samples fall at rock-weathering dominance zone. The geochemical processes and temporal variation in groundwater in this area are influenced by evaporation processes, ion exchange and dissolution of minerals. According to water quality index (WQI) of the study area exhibits 8xa0% of the groundwater samples fall at the unsuitable zone for drinking purpose. The spatial distribution map of WQI shows the poor quality of the water decrease toward the southern part of the study area. The results of SAR, Na%, PI, RSC and MH show that majority of groundwater samples are suitable for domestic and agricultural purposes. By the hydrogeochemical analysis, aquifer rock weathering, seawater intrusion, sewer leakage are the dominant factors that determine the major ionic composition. The proper management plan is necessary to preserve valuable groundwater resources.

Geostatistical techniques to evaluate groundwater contamination and its sources in Miryang City, Korea

Miryang City has high seasonal variations in precipitation and small number of surface reservoirs. It uses much groundwater for living and irrigation purposes. This study delineates the characteristics and the controlling factors of groundwater contamination using multivariate statistical analyses and kriging method. GIS spatial maps showed that groundwater contamination was occurred mainly in the central and southern areas and partly in the southwestern and northern areas. It may be attributed to the effect of residual saline water, irrigation, livestock wastes and municipal sewage. Ca-HCO3 water type was the most predominant in the groundwater of the study area. Ca-Cl2, Na-Cl and Na-HCO3 water types were dominant in order, due to the influence of residual saline water and anthropogenic activity. Geostatistical techniques were applied to classify the groundwater samples and to identify the geochemical processes and sources controlling the groundwater geochemistry. The scatter diagrams of factor score versus topographic elevation and groundwater level represented that groundwater was influenced by saline water and NO3-N at <85xa0m of well elevation. The areas and degrees of groundwater contamination were understood from the spatial distribution maps of factor scores versus groundwater level. Chemical characteristics and contamination sources of groundwater were identified from cluster and factor analyses. Kriging method was useful for the production of distribution maps showing the degree and location of groundwater contamination. Thus, geostatistical techniques including factor analysis, cluster analysis and kriging method played very important roles in evaluating groundwater contamination and identifying contamination sources.

Assessment and Distribution of Metals Contamination in Groundwater: a Case Study of Busan City, Korea

The present research was carried out to assess the pH, electrical conductivity (EC), dissolved oxygen (DO), and metal concentrations of groundwater in Busan City, Korea. Forty groundwater samples were collected at the environs of major residential and recreational area. The physicochemical parameters (pH, EC, and DO) and metals (Fe, Mn, Cu, Cd and Zn) were analyzed. The metals in groundwater were listed in the descending order of concentration like

Identification of groundwater contamination sources in Dindugal district of Tamil Nadu, India using GIS and multivariate statistical analyses

hbox {Zn}> hbox {Mn} > hbox {Cu} > hbox {Fe} > hbox {Cd}

Assessment of groundwater quality using GIS and CCME WQI techniques: a case study of Thiruthuraipoondi city in Cauvery deltaic region, Tamil Nadu, India

Zn>Mn>Cu>Fe>Cd. Groundwater pollution indices (heavy metal evaluation index, heavy metal pollution index and degree of contamination) revealed that most of groundwater samples belonged to the low to medium zones. GIS-based spatial maps suggested that the activities of seawater intrusion and salinized river water are pervasive process in this area. Correlation and cluster analyses were used to assess the intensity and source of pollution in groundwater. It was suggested that groundwater quality was polluted mainly by seawater intrusion, infiltration of salinized river water, sewage leaked from sewer, and groundwater discharge from the subway. The pollution status of groundwater systems in this case study are of great environmental and health concerns.

An assessment of selected hydrochemical parameter trend of the Nakdong River water in South Korea, using time series analyses and PCA

This research aimed at developing comprehensive assessments of physicochemical quality of groundwater for drinking and irrigation purposes at Dalcheon in Ulsan City, Korea. The mean concentration of major ions represented as follows: Ca (94.3xa0mg/L)u2009>u2009Mg (41.7xa0mg/L)u2009>u2009Na (19.2xa0mg/L)u2009>u2009K (3.2xa0mg/L) for cations and SO4 (351xa0mg/L)u2009>u2009HCO3 (169xa0mg/L)u2009>u2009Cl (19xa0mg/L) for anions. Thematic maps for physicochemical parameters of groundwater were prepared, classified, weighted, and integrated in GIS method with fuzzy logic. The maps exhibited that suitable zone of drinking and irrigation purpose occupied in SE, NE, and NW sectors. The undesirable zone of drinking purpose was observed in SW and central parts and that of irrigation was in the western part of the study area. This was influenced by improperly treated effluents from an abandoned iron ore mine, irrigation, and domestic fields. By grouping analysis, groundwater types were classified into Ca(HCO3)2, (Ca,Mg)Cl2, and CaCl2, and CaHCO3 was the most predominant type. Grouping analysis also showed three types of irrigation water such as C1S1, C1S2, and C1S3. C1S3 type of high salinity to low sodium hazard was the most dominant in the study area. Equilibrium processes elucidated the groundwater samples were in the saturated to undersaturated condition with respect to aragonite, calcite, dolomite, and gypsum due to precipitation and deposition processes. Cluster analysis suggested that high contents of SO4 and HCO3 with low Cl was related with water-rock interactions and along with mining impact. This study showed that the effluents discharged from mining waste was the main sources of groundwater quality deterioration.

Identification of saline water intrusion in part of Cauvery deltaic region, Tamil Nadu, Southern India: using GIS and VES methods

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 200xa0Mt 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 8xa0% 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.

Factors controlling groundwater quality in the Yeonjegu District of Busan City, Korea, using the hydrogeochemical processes and fuzzy GIS

Fourteen water and sediment samples were collected from the Nakdong River Basin in Korea to evaluate the physico-chemical parameters (pH, dissolved oxygen, chemical oxygen demand, biological oxygen demand, total organic carbon) in water and total heavy metals (Cu, Zn, Pb, Cd, As) in surface sediments. The assessment of physico-chemical parameters indicates that river water and sediments in the study area were strongly impacted by industrial wastewater, irrigational effluents and domestic sewage. The overall average concentrations of metals in sediments were Cu (6.41xa0mg/kg), Cd (0.11xa0mg/kg), Pb (4.72xa0mg/kg), Zn (16.8xa0mg/kg), As (0.19xa0mg/kg), and the order of the concentrations was Znxa0>xa0Cuxa0>xa0Pbxa0>xa0Asxa0>xa0Cd. Geo-accumulation index (Igeo) indicates that most of samples fall at unpolluted to medium category, while contamination factor values fall at the medium to very high pollution zone. Pollution load index also suggests that all samples fall at progressive pollution sector. Multivariate statistical analysis and pollution index methods were helpful for the classification on the basis of the contamination sources and origin of heavy metals. In conclusion, this study clearly infers the fact that the cause of metal pollution in this region is mainly due to the effluents discharged from factories, agricultural fields and sewers.