Water Quality Index

Large-scale mass poisoning through arsenic contaminated groundwater is a global concern and Bangladesh is among the countries exposed to high concentrations of arsenic in groundwater. As arsenic is a widespread contaminant, several studies have been conducted on it but only a few of these studies were held on micro regions by assessing its role on water quality index. In this study, the source and mobilization of arsenic, its effect on soil and plant, level and consequence of toxicity in human health along with current and potential methods to eliminate arsenic from groundwater in Bangladesh were reviewed based on previous researches. Along with the review, an experimental study was also carried out in an arsenic prone region of Bangladesh named Faridpur Sadar Upazila to delineate the role of arsenic in contamination by generating two synthetic scenarios where water quality was measured by the weighted arithmetic water quality index (WQI) method. From the review it was found that, both geogenic, as well as anthropogenic sources, contribute to arsenic affluence in groundwater in Bangladesh. The most accepted theory states that the Himalayan is the primary geogenic source of arsenic in the Bangladesh. Arsenic arrived in the aquifer transported with sediments which eventually releases into groundwater by several biogeochemical processes. This arsenic-contaminated groundwater is extensively used for drinking purpose and irrigation resulting in accumulation of arsenic in human body, soils and plants. Moreover, the accumulated arsenic in soil and plants transmits into the human body jeopardizes human health. Though, several arsenic removal technologies are now in practice in Bangladesh, more eco-friendly and convenient methods may be utilized to attenuate the level of toxicity. The experimental study revealed that, if the arsenic amount was reduced from the present condition, the overall WQI increases considerably. At one location, the index changed from category E to category B while considering a synthetic scenario of no arsenic in water. This indicates that arsenic is the key pollutant of groundwater in the area. This paper expects the kind attention of the local people and policymakers about the severity of arsenic pollution in the region.

Assessing the vulnerability of groundwater is the first step toward careful management of water resources to avoid or, at least, to minimize impacts on agriculture. The objective of this study was to propose a simple method to assess the groundwater quality and to map its spatial variation in terms of suitability for irrigation in the Darb El-Arbaein area, Southwestern Desert, Egypt. Thirty-six surveyed wells were used to assess and map the groundwater quality. For calculating the Water Quality Index (WQI), a total of 20 (13 chemical, two physical, and five calculated) parameters were considered e.g., EC, pH, Cl, SAR, B, Zn, iron, Mn, Pb and Cd. The results of analyses were used to propose a water quality model. The different water quality maps were produced using GIS software. The results show that three water samples fall into the moderate WQI. Most of the samples (26) fall into the unsuitable WQI category. Seven samples fall into the suitable WQI category. Groundwater samples that fall into the low salinity hazard class and high WQI can be used for irrigation of most crops and the majority of soils. The WQI for the samples ranges from 47.9 to 88.6. The WQI distribution maps delineating an area of 266.66 ha are suitable for irrigation in villages (3,4) and areas of 382.35 ha are moderately suitability for villages (1,2). Since the final map shows the spatial distribution of irrigation water quality in the area, it is now much easier for a decision maker to assess the water quality for irrigation and to locate the most suitable site for drilling wells. The present study demonstrates high efficiency for GIS to analyze complex spatial data and groundwater quality mapping.

"This paper presents a mathematical model of water quality rehabilitation by utilising rainwater, which is separated into initial polluted rainwater and later unpolluted rainwater. The planned Haigang city, belonging to Shanghai metropolis in China, is taken as a case example. An analysis is made on how to utilise rainwater and appraise its function in a water quality rehabilitation scheme. It is demonstrated that this method can significantly reduce both project investment and operation costs. Moreover, appropriate drainage plan scheme is presented to address the initial polluted rainwater problem. Thus, the conflict between drainage and rainwater utilisation can be resolved appropriately.

Keywords: mathematical model; water quality index; WQI; water quality rehabilitation; rainwater utilisation; drainage planning; wastewater treatment plant"

Plants with different abilities for osmotic adjustment (cowpea, bean, and sugarbeet) were subjected to gradually decreasing soil water content. During the development of water deficit stress, various plant water parameters were measured to characterize their relationship to the near infrared R 1300 /R 1450 leaf water index, which is based on the measurement of light reflected from leaves. In all three species, leaf water thickness (LWT), leaf cell relative water content (RWC), and overall leaf thickness remained relatively constant under moderate water deficit stress. However, at the point when plants could no longer cope with the increasing level of water deficit stress, LWT, RWC, and leaf thickness were found to decrease substantially, signaling the onset of leaf dehydration. The R 1300 / R 1450 leaf water index followed the RWC very closely in cowpea and bean leaves, and with some time lag in sugarbeet leaves. The R 1300 /R 1450 index may therefore be used as a feedback-signal in precision irrigation control, signaling effectively the physiological response of plants when water deficit stress becomes detrimental. RWC and the R 1300 /R 1450 index were linearly correlated in cowpea and bean leaves, but not in sugarbeet leaves.

In recent years, artificial intelligence methods have demonstrated to be appropriated for treatment of environmental problems. This paper presents a novel work for assessment and prediction of the water quality in shrimp aquaculture based on environmental pattern processing. Water quality studies are based on analyzing negative concentrations of compounds in shrimp ponds that inhibit the good growing and reproduction of organism. The physical-chemical variables are classified basing on the negative ecological impact using the Gamma (Γ) classifier, which calculates the frequency and the deviation of the measurements from a specific level. A fuzzy inference system processes the level classifications using a reasoning process that determines when a specific concentration is good or harmful for the organism, and providing a water quality index, which describe the condition of the ecosystem: excellent, good, regular and poor. An autoregressive model (AR) predicts a section of an environmental signal using historical information, the set of predicted variables are assessed in order to estimate future water quality conditions in the system. This methodology emerges as a suitable and alternative tool to be used in the developing effective water management plans.

Introduction River pollution is one of the serious risks to the environment, water systems, and human health. Regular monitoring and protection of river water quality is therefore vital to meet environment, and human needs. The increasing trend to fresh water highlights the management of river water resources as a crucial resource. Meanwhile, population growth, irregular urbanization, industrialization, overuse of chemicals materials in agriculture (such as fertilizers and pesticides), discharge of domestic sewage, and solid waste into watercourses, sand mining in riverbeds, water transfer diversion, has seriously challenged the rivers regimes and river ecosystems. Materials and Methods The effect of agricultural activities on water quality in the Chalus River was examined. Sampling was conducted and analyzed in surface water at three points from October 2019 to September 2020. Three surface water samples were collected from each station and water quality variables were analyzed. The following water quality parameters have been analysed in the current study; temperature, pH, conductivity, soluble solids, suspended solids, turbidity, salinity, reduction of oxidation potential, alkali, total hardness. Also, oxygen demand parameters of dissolved oxygen, oxygen saturation, biological oxygen requirement were examined. Meanwhile, the nutrient-related water quality parameters include N-NH4, N-NO2, N-Np3, total phosphate, total phosphorus are also evaluated. The heavy metals, inorganic pollution parameters, and suspended chlorophyll content of biological parameters were the other investigated parameters. Multiple statistical methods were used for the results of analyzing the parameter including principal component analysis (PCA), Pearson correlation Coefficient (PCC), and cluster analysis (CA). In addition, water quality index (WQI) was used for determining quality of surface water, hazard quotient (HQ), and hazard index (HI) for evaluating the public health risk for heavy metals. Results and Discussion The water quality of Chalous River has decreased from S1 station to downstream. The water quality index based on public health risk assessment showed that station S1 water could be used as drinking water and did not pose a potential risk to the health of adults and children. However, the water quality at Station S2, and especially Station S3, cannot be used for drinking puprpos, due to improper quality and may poses potential risks to the health of adults and children. The station S1 with an average of 15.62 categorized in the excellent water quality category. Meanwhile, the station S2 and S3 with an average of 25.5, and 49.8 assigned as good water quality status, respectively. The amount of As, Cd, Co, Ni, Pb was very small at the studied stations. The hazard coefficient (HQ) and hazard index (HI) values calculated to determine the risk of heavy metal effects on health were identified as non-carcinogenic. HI values of heavy metals calculated for adults and children were Mn> Cu> Al> Zn> Fe, respectively. The manganese and copper are more involved in non-carcinogenic health risks. Also, the values of HQingestion and HQdermal values and the HI value are less than one. Conclusion A combination of point and non-point source pollution have been identified as the main source of water quality deterioration. The water quality parameters of Chalous River in S1 station has not exceeded the permissible level of the national standard of Iran. While, the water quality in S2, and S3 stations has decreased that poses potential risks to the human health and need a pollution prevention action plan. The factors such as municipal wastewater, septic tank and water leakage from horse stables, natural and artificial fertilizers used in agriculture, runoff and rock pebbles in the basin are the causes of pollution.

— In the present paper, an attempt has been made to work out water quality index (WQI) to assess the groundwater scenario of different geo-morphological units of Bist-Doab, Punjab, India. Data of 51 groundwater samples collected from piezometers, dug wells, bore wells are used. The WQI is computed using seven parameters viz. pH, Total Dissolved Solids, Total Hardness, Fluoride, Chloride, Sulfate and Nitrate. However, the WQI results show that the overall water quality class is 'good' and water is acceptable for domestic use but continuous monitoring of groundwater is required to protect water from any possible contamination in future due to growing agricultural activities in the area.

Water quality is considered as the most important factor in aquaculture production systems affecting fish health and performance.  Water quality can be considered good if it relates to what aquaculture wants and needs to survive and develop, which means that aquacultured farmers must be able to understand the water quality requirements of their cultured products to ensure their fast growth and survival. Different species of fish have different and particular aspects of water quality needs in which they can live, grow and reproduce.[1]–[5] It is, therefore, imperative for fish producers to make sure that the physical and chemical conditions of pond water remain, as much as possible, within the optimum or acceptable range of the fish under culture all the time. Fish may show poor development, erratic behavior, and signs of disease or parasite infestations outside of these acceptable ranges. Fish kill can occur in extreme cases or where poor conditions persist for extended periods of t...

AbsTRAcT In the present study, water quality index is worked out to assess the groundwater scenario of Haridwar district, Uttarakhand, India. Data of forty groundwater samples collected from piezometers, dug wells, bore wells are used. The Water Quality Index is computed using seven parameters viz. pH, Total Dissolved Solids, Total Hardness, Fluoride, Chloride, Sulfate and Nitrate. The WQI results show that the overall water quality class is 'good' and water is acceptable for domestic use.

Groundwater is a natural resource for drinking water .In addition to the population growth, urbanization and industrialization also extend the demand of water. Providing safe drinking water supply to the ever growing urban and sub-urban population is going to be a challenge to the civil authorities, city planners, policy makers and environmentalists. Groundwater is a major source of drinking water in both urban and rural areas of Mandya. Mandya city is rapidly raising population, changing lifestyle and intense competition among users-agriculture, industry and domestic sectors is driving the groundwater table lower. Besides, discharge of untreated wastewater through bores and leachate from unscientific disposal of solid wastes also contaminate groundwater, thereby reducing quality of fresh water resources. The present work is aimed at assessing the water quality index for the ground water samples of Sugar town, Mandya city. The groundwater samples of about 40 samples were collected and subjected for a comprehensive physicochemical analysis. The purposes of this investigation are to provide an overview of present ground water quality for the following 12 parameters such as pH, total hardness, calcium, magnesium, chloride, nitrate, sulphate, total dissolved solids, iron, fluoride, alkalinity are to be considered for calculating the WQI. The results are analyzed by WQI method for predicting water quality. Water Quality Index (WQI) is a very useful and effective way for assessing the quality of water. WQI is a very useful tool for communicating the information on overall quality of water.

In Malaysia, there are two main indices which are Water Quality Index (WQI) and Air Pollutant Index (API). These indices are used as an indicator for the water quality and ambient air quality status of the environment. In conducting research regarding water and air quality, lots of time has been used to conduct other activities, an application to calculate the indices might come in handy. This project aims to construct an application for the computation of WQI and API using Visual Basic for Applications (VBA) available in Microsoft Excel. VBA is actually a programming language of Microsoft Excel and can be used to write programming and run through in an Excel workbook. The user only required to enter the value for each parameter and then press �OK� to automatically calculate the index. This will provide instance result without wasting time just to refer to the class standard and other formula. The application also has been used as a teaching tool for the secondary students. An e...

Water is one of the most indispensable resources and is the elixir of life. Modern civilization, industrialization, urbanization and increasing populations have led to rapid degradation of groundwater quality. It is estimated that approximately one-third of the world's population use groundwater for drinking. Those around Varanasi depend totally on groundwater resources. Heavy and constant groundwater use, without restriction, is lowering both the water table and water quality. Any type of contamination present in groundwater, will leads to several health related problems. Owing to this pressure on resources, the water quality around Varanasi, in the middle Ganga plain, was studied. Twelve water quality parameters (iron, nitrate, fluoride, chloride, pH, TDS, alkalinity, turbidity, sulfate, calcium, magnesium, and hardness) were investigated relating to 2015/16 for eight blocks of Varanasi district. Groundwater quality was calculated by using correlation, principle component analysis (PCA) and water quality index (WQI). In general, good water quality was found in all but one block Kashi Vidya Peeth has poor water quality.

This study was conducted to investigate the effects of Al-Rasheed power plant (RPP) effluents at Al-Zafaraniya city on the physical – chemical of the Tigris River by using Canadian Water Quality Index(CCME WQI).Water samples were taken monthly at four positions and 11parameters were analyzed . The results of this study conducted that there was a significant impact of the RPP effluents on increase of water temperature, turbidity and electrical conductivity, and there was an increase in the phosphate concentration and water hardness at station 2 and the model classified water of Tigris river as poor in winter and fair to marginal in rest season for drinking and aquatic life

Water quality index (WQI) is a remarkable and unique technique to rate and to depict the overall water quality status in a single term. To calculate the WQI the influence of different water quality parameters are studied in detail. The sums of these are then substituted in the numerical formula and the WQI is obtained. The different parameters gives the exact quantity of the impurities present in the water and its toxic level, but the WQI suggests the overall quality of water and also that whether it should be healthy to be used for biotic and abiotic environment. In other words it explains that how healthy the water is.

Surface water resource in the Upper Part of Dong Nai (UPDN) River Basin has an important role for socioeconomic development of provinces in the Southeast region of Vietnam. The purpose of this paper is to determine the influence of anthropogenic sources of pollutants on water quality parameters by using the integration solution between the Water Quality Index (WQI) and multivariate statistical techniques. In this study, eight physico-chemical parameters of surface water samples were collected from 42 monitoring sites in the UPDN for assessing spatial and temporal water quality variations during the period of 2012-2016. WQI and the multivariate statistical techniques comprising hierarchical cluster analysis (HCA), One-way analysis of variance (ANOVA), and Spearman correlation analysis (SCA) were used to evaluate characteristics of surface water quality. The results revealed that surface water of the river was moderately polluted and the water quality highly varied between monitoring sites and seasons. The study also found that the concentrations of Total Suspended Solids (TSS) were the most prominent parameter affecting water quality in the rainy season (r =-0.85). The proposed solution demonstrated integrated tools rather than the conventional techniques in assessing the river water quality. This integration technique could be an efficient approach to communicate information on water quality for the sustainable practices of watershed management in the Upper Part of Dong Nai River Basin.

The Water Quality Index (WQI) is a single number that expresses water quality rating by aggregating the measurement of water quality parameters. The aim of this paper is to make an assessment of the Water Quality of the groundwater in the Northern Aquifer in Mauritius by making use of water quality indices using the Brown et al and the Canadian Council of M inisters of the Environ ment Water Quality Index (CCM E WQI) methods. Six water quality parameters were used to determine the WQI at 16 different sampling stations within the northern aquifer. The two methods provided two different rat ings; 'Good Water Quality' rating for the Brown et al method and 'Excellent Water Quality' rat ing for the CCM E WQI method. The ratings obtained from both WQI indicate that the water is suitable for drinking purposes. This study shows that WQI can be a valuable tool for water administrators and policy makers for assessing and rating the suitability of the water for different uses.

a b s t r a c t This paper proposes a water quality index (WQI) to subsidize management actions in the Mé dio Paranapanema Watershed in Sã o Paulo State, Brazil, as a simple pollution indicator for aquaculture activity. Water quality of the Macuco and Queixada rivers was investigated for 2 years (from May 2003 to May 2005). The index proposed in this work is composed of three measurable environmental parameters-turbidity, total phosphorus and dissolved oxygen. Concentrations of these three variables were normalized on a scale from 0 to 100 and translated into statements of water quality (excellent, good, regular, fair and poor). The index was applied to seventeen monitoring points in the aquatic bodies described above and compared to others, one being that used by the Environmental Protection Agency of United States and proposed for the National Sanitation Foundation, other employing minimal index and the last one considering the minimum operator concept. The results show that the degradation in this watershed from aquaculture activity can be easily inferred with this

The study carried out on Khan Sarovar treatment plant's water deals with the influence of environmental parameters on the ground water quality and water bodies. The waste water of approximately 60,00,000 liters' quantity is directly disposed into the canal, after treatment. The water which is chemically and biologically harmful should be treated or its assessment should be happens so as to cure it in better way. The assessment, analysis and periodical testing of the water samples for quality have been done. There are many modes and ways to assess the water quality. The water quality of drinking, washing, irrigation and industrial use may vary as per the minimum requirements of biological or physical parameters but the waste water and its spatial effect up to 5 kilometers have to be checked and assessed for direct use. Water Quality Index is a useful representation of overall quality of water for public or for any required use as well as in the pollution demolition programmes...

Water quality is considered as the most important factor in aquaculture production systems affecting fish health and performance. Water quality can be considered good if it relates to what aquaculture wants and needs to survive and develop, which means that aquacultured farmers must be able to understand the water quality requirements of their cultured products to ensure their fast growth and survival. Different species of fish have different and particular aspects of water quality needs in which they can live, grow and reproduce.[1]-[5] It is, therefore, imperative for fish producers to make sure that the physical and chemical conditions of pond water remain, as much as possible, within the optimum or acceptable range of the fish under culture all the time. Fish may show poor development, erratic behavior, and signs of disease or parasite infestations outside of these acceptable ranges. Fish kill can occur in extreme cases or where poor conditions persist for extended periods of time.[1], [4], [6]-[8] Using water sampling to monitor water quality takes up time, while laboratory results do not show the current state of water in fish ponds, which is critical information needed by fish farmers. Water quality monitoring in fish ponds should be in real-time, analysis of water parameters must be done as soon as possible to ensure water quality and its acceptability for aquacultured products. The purpose of this study is to develop a system that can monitor water parameters in fish ponds analyze and evaluate these parameters to determine the suitability and survivability rate of aquacultured products base on water quality using machine learning algorithms regression tree and decision tree in accordance with the water quality requirements of cultured products. With the help of Arduino microcontroller device that uses IoT (Internet of Things) technology. By implementing this study, it was found out that the system effectively helps the fish farmers to manage and help maintain the water quality of their fish ponds it minimizes losses due to untimely solutions to water quality problems and promotes a healthy environment which helps increase the growth and survival of aquacultured products. It also increases the fish farmer harvest and income, which creates a positive impact on agricultural productivity in terms of fish farming.

This study dealt with the application of Geographic Information System (GIS) vis a vis water quality index of
marine water ecosystem in Opol, Misamis Oriental. Specifically this study aimed on (a) establishing GIS maps on
wide range distribution of physicochemical parameters of water (b) determining the physicochemical parameters
of water along residential, commercial and recreational areas and (c) comparing the values of physicochemical to
the standards set by Department of Environment and Natural Resources (DENR) Philippines. There were three
(3) sampling stations categorized as residential, commercial and recreational areas and sampling was conducted
within three (3) months during Amihan (northeast monsoon) in the Philippines. Research design used was a
combination of descriptive, qualitative and evaluative design. Results showed Relative Humidity (RH), air
temperature, Dissolved Oxygen (DO), water temperature, density, conductivity, turbidity, salinity, and Total
Suspended solids (TDS) were prevalent in recreational area, while DO and Biochemical Oxygen Demand (BOD)
in commercial area, and only pH and BODin residential area. Statistical analysis showedsix (6) andeight (8) of
the parameters in between subjects and within-subjectsshowed significant difference, respectively. However,
one-sample t-test showed that the three sites are equal and not statistically significant. Hence, GIS is an effective
tool to assess area for possible distribution of species and vulnerability to polluted waters.

Water quality tool has been optimized by application of Water Quality Index (WQI) method. WQI measures the quality of underground water in North West Jaipur city and agglomerates during April to May 2010. Ground water collected from pointed places as Bore well and Tube well sources. Various parameters are used to calculate WQI including pH, Total Dissolved Solids, Turbidity, Total Hardness, Chloride, Nitrate, Electrical Conductance, Sodium and Potassium .Ground water quality of North West Jaipur as WQI confines WQI index of 103.98 exhibits "Poor Water Quality" observed and developed in pointed areas obtained as quality modals in which three defined aspects (1) Arithmetic mean, (2) Standard Deviation, (3) Coefficient variation, are included and optimized. WQI provides comprehensive information for water quality assessment of Jaipur. Water quality in North West region of Jaipur specially of Brahmpuri, Jhotwara, Bindiaka and Railway station pointed areas were found poor quality of underground water. It has been concluded and optimized that high value of Total Hardness, TDS, Nitrate and Electrical Conductance defines the poor quality of water lead to higher side of WQI.Results shows Jhotwara and Railway Station area have very high value of hardness (upto 631 mg/L) as compared with mean value of hardness in North-West. Accordingly, hard water is not suitable because of the precipitating materials as scale and sludges have adverse effects on human being.

Water Quality Index (WQI) has been calculated for surface drinking water in Nadia district, West Bengal, India at six different sites in the post-monsoon season Water quality parameters were selected as per the BIS guidelines and eight water quality physico-chemical parameters were estimated following the standard methods and procedures. Drinking water of some sites was found to be moderately contaminated and at other sites to be of good quality water as per Water Quality Index during the year 2007. In general, the water quality showed deterioration. It is felt that some remedial measures are urgently required to optimize the water quality for this region.

Issues connected with high quality casting alloys are important for responsible construction elements working in hard conditions. Traditionally, the quality of aluminium casting alloy refers to such microstructure properties as the presence of inclusions and intermetallic phases or porosity. At present, in most cases, Quality index refers to the level of mechanical properties – especially strength parameters, e.g.: UTS, YS, HB, E (Young's Modulus), K 1c (stress intensity factor). Quality indexes are often presented as a function of density. However, generally it is known, that operating durability of construction elements depends both on the strength and plastic of the material. Therefore, for several years now, in specialist literature, the concept of quality index (QI) was present, combines these two important qualities of construction material. The work presents the results of QI research for casting hypoeutectic silumin type EN AC-42100 (EN AC-AlSi7Mg0.3), depending on different variants of heat treatment, including jet cooling during solution treatment.

The use of the water quality index (WQI) and the dissolved oxygen deficit (D) as simple indicators of the watersheds pollution was investigated and compared in the Municipality of Las Rozas (north-west of Madrid, Spain). The quality of the water in Guadarrama and Manzanares rivers and Paris Park ponds, the main watersheds of this area was investigated during 2 years

In present work, it was envisaged to review the methods currently available for assessment of the groundwater vulnerability and to develop an appropriate method suitable for the alluvial aquifers of the Ganga-Yamuna interfluve area. Attempts were also to develop  a multipurpose database in GIS environment, and to validate the developed method by comparing its findings against the observed water quality characteristics of the region.
The study area is the northern part of the vast Indo – Gangetic Plain in India and lies between latitudes 29o 33/ 51/ / to 30 o 19/ 10/ / N and longitudes 77 o 06/ 20/ / to 78 o 20/ 15/ /  E with a total geographical area of approximately 4900 km2. Administratively, the study area covers the districts of Hardwar in Uttaranchal and Saharanpur in Uttar Pradesh, and has a population of about 4.3 million as per Census of 2001. The Ganga River and its tributary, the Yamuna, are the two major rivers in the region. These two rivers are perennial in nature and form the eastern and western boundaries of the study area. Other small intermittent streams like Ratmau River, Solani, and Banganga – the tributaries of the Ganga, and Hindon River, a tributary of the Yamuna, drain the area. A network of canals exists in the study area for meeting the irrigation needs; the notable being the Upper Ganga canal and Eastern Yamuna canal along with their distributaries and branches. The climate of the area is humid and subtropical. The rains occur mainly during July to middle of September with annual average rainfall of about 100 cm.
LISS-III data of India Remote Sensing (IRS) satellite was used to prepare the land use map of the study area. On the basis of these data, the whole area was classified into three land use classes, i.e. urban, rural (including agriculture), and forest. The field monitoring was carried out during January 2002 to December 2003, through extensive field surveys covering entire study area. Groundwater samples (136 no.) were collected from various sites well distributed among various land use types in the study area and. Also, soil samples (48 no.) were collected from different sites covering all the land use categories. Geological and hydro-geological settings were examined for the study area. The depth to groundwater was monitored from the observation wells (119 no.). Besides, historic data available for past 10 years was also taken from Uttar Pradesh Groundwater Department, Roorkee. Groundwater recharge was estimated by Tritium tagging method at five locations during the period from Jun 2002 to Nov 2002. These, alongwith earlier data available at National Institute of Hydrology, Roorkee were used.
A Digital Elevation Model (DEM) was prepared by digitization of bench mark and topographic points from relevant maps. The DEM was in turn, used for the construction of the slope map. The depth to groundwater map of the study area was generated from the observed data. The soil samples were analyzed to ascertain the soil texture and to prepare the soil map. This map showed that the most of the northern part, paleochannels and active floodplains of rivers have soils of sandy loam texture whereas the remaining part of the study area is covered by soils having silty loam.  Considering the soil texture as an appropriate source factor of variation, the average recharge percentage was calculated as 6.3 % in silty loam soils and 15.5 % in sandy loam soils. The software RockWorks99 was used to prepare the geological fence diagram. Hydraulic conductivity map was prepared using Hydraulic conductivity data in GIS environment. The flow direction map, showed that the ground water flows from the northern and northeast part (the hilly area) to southern and southwestern part and follows the general topography of the study area. Hindon River and Solani River are fed by groundwater in the southern part. The hydraulic conductivity in the study area varies between 10 m/day and 48 m/day. The south-western part shows higher values in general, whereas the north-western part shows lower values.
The quality of the soils in the study area was analyzed. The results exhibit that in general the urban soil has the highest values of all the physicochemical parameters followed by the rural and forest soils indicating an important role of urban activities
The groundwater samples were analyzed for various physicochemical parameters like pH, EC, TDS and major ions (Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, SO42-, CO32-, F-), nutrients (NO3-, PO43-), total organic carbon (TOC) and heavy metals (Cd, Fe, Mn, Ni, Zn, Pb, Cr, Cu). In general, the groundwater quality in the study area does not indicate much variation between postmonsoon and premonsoon periods. Further, all major ions, except NO3-and K+, show an increasing trend from north to south and southwest. The groundwater is generally alkaline in nature with pH ranging from 7.01 to 8.90. The TDS values range between 117 to 1002 mg/l. HCO3- is the dominant major anion followed by Cl->SO42-> NO3->F->PO4 3- whereas Ca2+ is the major cation followed by Na+>Mg2+>K+. The heavy metal Zn is dominant followed by Mn>Fe>Pb>Cd.
The calcium-bicarbonate facies are dominant in the groundwater of the study area, indicating that a substantial part of ground water is derived as recharge from the Bhabar zone in the north. Generally, the concentration of chemical parameters, except NO3- and SO42-, follow a decreasing trend for urban > rural > forest land use categories, whereas NO3- and SO42- follow the decreasing trend for forest > urban > rural land use. Besides, a few samples show some parameters like total alkalinity (TA), nitrate, TDS, and Calcium having higher ranges than acceptable limits of Indian standard (BIS: 10500) for drinking water. Among the heavy metals, tolerance limits of cadmium, manganese, lead and iron are violated in several samples. 
On the basis of demonstrated violation of the acceptable limits, the quality parameters like TDS, Ca2+, Total Alkalinity (TA), NO3-, Cd, Mn, Pb, and Fe have been selected for computation of an Index of Aquifer Water Quality (MIAWQ), utilizing the framework as proposed by Melloul and Collin (1998). The index was modified for the present case in the sense that the weights to these eight parameters were, however, assigned as per their analytical hierarchy in the human health (effecting) significance and not in a subjective manner (as attempted in the original work of Melloul and Collin). The values of MIAWQ (modified index) show an increase from north, north-east to south and south-western parts of the study area.
The groundwater vulnerability mapping was carried out using two approaches viz. standard DRASTIC method and a modified DRASTIC-MOD method the study area. The DRASTIC parameters were evaluated in GIS environment as seven restart-map layers. The rating percentages were subsequently added to obtain the total cell rating. The DRASTIC index in the study area ranges from 122 to 183. The east and south-west corners of the study area and the paleochannels in the southern part show higher vulnerability index values.
While applying the DRASTIC method on the present study area for assessment of vulnerability, following limitations were noticed:
 The proposed rating scale for the parameter “Impact of vadose zone” did not adequately address the implicit variability among the geological constituents of the vadose zone viz. sand gravel, silt and clay, and the resulting complexity.
 The “Hydraulic conductivity” values observed in study area mostly surpassed the highest limit/range of the rating scale rendering observed spatial variability meaningless with respect to the aquifer vulnerability.
 Observing definitive signals about the influence of land use (urban > rural and agricultural > forest) on the soil and groundwater quality, the parameter “land use” appeared to also have on important bearing the status of aquifer vulnerability alongwith other parameters proposed earlier.
Due modifications were incorporated in the original DRASTIC model in view of the above and the modified (DRASTIC-MOD) index map was sub-divided into four classes, (i) 100 – 119 with low risk in the north part of the study area (forest area), (ii) 120 – 159 with moderate risk in the Bhabar zone with deep depth to groundwater and forest area, (iii) 160 – 199 with high risk in most parts of the study area, these values resulting mainly from cumulative effects of rural and agricultural land use, low to moderate depth to groundwater and high recharge coefficient. (iiiv) Indices of 200 and above with very high vulnerability in some parts of the study area, reflecting the shallow depth to groundwater, high recharge and high urbanization related activities. DRASTIC-MOD indicates high vulnerability in the southern parts of the study area indicating higher risk of groundwater pollution.
In order to validate the projected risk of vulnerability with actual groundwater quality statues in the region, DRASTIC and DRASTIC-MOD maps were correlated with modified Index for Aquifer Water Quality (MIAWQ). The MIAWQ showed high significant correlation with DRASTIC-MOD map.
The differences observed in the spatial distribution of vulnerability estimates obtained from both the methods (DRASTIC and DRASTIC-MOD) indicate that in the areas with existing well defined land use practices, vulnerability estimation should necessarily include “land use” as a parameter. Further, in view of a good correlation between the DRASTIC-MOD and MIAWQ maps, it may be inferred that the “risk of vulnerability” corresponds quite well with the existing water quality scenario in the study area, a finding not commonly reported by researchers earlier. This also highlights the need of initiating corrective measures in many parts of the study area as well as to establish a suitable monitoring protocoal to detect adverse quality trends in the future.

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?[Ca2?[Mg2?[K?, while that of anions is Cl-[HCO3
-[SO4 2-[NO3 -[F-. 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 8 % 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 man- agement plan is necessary to preserve valuable groundwater resources.

A comprehensive chemical quality assessment of groundwater resources in the Talensi District has been conducted using conventional graphical methods and multivariate statistical techniques. e study sought to determine the main controls of groundwater chemistry and its suitability for domestic and irrigation purposes in the district. Silicate and carbonate mineral weathering were identified as the main controls on groundwater chemistry in the district, with reverse ion exchange also playing a role. High nitrate and lead levels observed have been associated with agrochemicals and wastewater from farms and homes. ree main flow regimes have been identified with Q-mode cluster analysis, in which mixed cation water types have been revealed, where areas designated as recharge zones are dominated by Na + + K +-Mg 2+-HCO 3 − fresh water types characterised by low mineralisation and pH, which evolve into Mg 2+-Na + + K +-HCO 3 − fresh water type with corresponding increased mineralisation of the groundwater. Based on the water quality index (WQI) technique modified for the district and an interpolation technique using ordinary kriging developed from a well-fitted exponential semivariogram for the estimated WQIs, the groundwater quality has been spatially classified as generally 'good' to 'excellent' for domestic purposes. Generally, the quality of groundwater for domestic usage deteriorates as one moves towards the north of the district, whereas waters in the east and west present the best quality. Classifications based on the United States Salinity Laboratory (USSL), Wilcox, and Doneen diagrams suggest that groundwater from the unconfined aquifers of the district is of excellent quality for irrigation purposes.

A Water Quality Index (WQI) is a useful statistical tool for simplifying, reporting and interpreting complex information obtained for any water body. A simple number given by any WQI model explains the level of water contamination .A water quality index carried out for Dal lake based on very important parameters can provide a simple indicator of water quality. The present study deals with the monitoring of variation of seasonal water quality index of Dal lake. The index is used to improve the comprehension of general water quality issues, communicates water quality status and illustrates the need for and the effectiveness of protective practices. It is found that in all cases the change in WQI value follow a similar trend throughout the study period. Water Quality Index of Dal lake for all four basins were (102.66,120.33,109.35,101.35) for all seasons summer, winter, monsoon thus it is found to be unfit for drinking.

Groundwater is a natural resource for drinking water. Like other natural resources, it should be assessed regularly and people should be made aware of the quality of drinking water. The present study is aimed at assessing the water quality index (WQI) for the groundwater of Surat city. This has been determined by collecting 125 groundwater samples from 39 areas of Surat city and subjecting the samples to a comprehensive physicochemical analysis. For calculating the WQI, the following 13 parameters have been considered: pH, total hardness, calcium, magnesium, chloride, nitrate, sulphate, total dissolved solids, iron, boron, and fluorides, COD and DO. The WQI for these samples ranges from 15.93 to 977.86. The high value of WQI has been found to be mainly from the higher values of iron, nitrate, total dissolved solids, hardness, fluorides, and boron in the groundwater. The results of analyses have been used to suggest models for predicting water quality. The analysis reveals that the groundwater of the area needs some degree of treatment before consumption.

The quality of groundwater was assessed by determining
the physicochemical parameters (pH, EC, TDS
and TH) and major ions concentration (HCO3, Cl, FSO4,
Ca, Mg, Na and K) around Dindigul district, Tamil Nadu,
India. The groundwater samples were collected from 59
bore wells covering the entire study area and analyzed using
standard methods. The GIS mapping technique were adopted
to highlight the spatial distribution pattern of physicochemical
parameters and major ion concentration in the
groundwater. Gibbs diagram reveals that the source of major
ions is predominantly derived from rock–water interaction
and evaporation dominance process. The salt combinations
of the aquifers are dominated by CaHCO3, mixed CaMgCl,
mixed CaMgHCO3 and CaCl facies type due to leaching
and dissolution process of weathered rocks. The Canadian
Council of Ministers of Environment Water Quality Index
(CCMEWQI) suggests that most of the groundwater quality
falls under good to marginal category. The statistical
analysis indicates that the presence of major ions and physicochemical
parameters are chiefly controlled by rock–water
interaction and residence time of the groundwater. However,
the major nutrient like nitrite in the groundwater probably
comes from anthropogenic process. Based on the groundwater
quality standards, majority of the samples are suitable
for drinking purposes except few in the study area.

Assessment of water quality of drinking water supplies has always been paramount in the field of environmental quality management. Groundwater quality of Dwarka has a special significance and needs greater attention of all concerned since it is the only major source for domestic, consumption. In this work we have estimated the ground water quality of Dwarka. Groundwater quality of Delhi needs greater attention because there is a continuous decline in water level and quality due to rapid urbanization and industrialization. The present study was attempted to access the groundwater quality of Dwarka district in Delhi. The samples of the ground water are collected manually from the bore wells which were approximately equally distributed all over 29 sectors and nearby areas. The samples were analyzed using standard procedures in the laboratory. The water quality index is a single number that expresses the quality of water by integrating the water quality variables. Its purpose is to provide a simple and concise method for expressing the water quality for different usage. Water Quality Index, has been calculated for the Dwarka sub-city and was studied for the suitability of water for drinking purposes and the results showed that the ground water quality was unfit for drinking in almost all of the areas scoring a water quality index greater than 110.

Water quality degradation in the Selangor River will still be present in the years to come since pollutant loads from poultry farms, municipal wastewaters, and industrial wastewaters are not envisaged to be handled effectively. This will be facing the problems of water quality status to use for multiple purposes and to provide its aquatic environment continuously. The water quality evaluation system is used to assess the water quality condition in the river. This system distinguishes two categories of water condition i.e., the water quality index and water quality aptitude. The assessment of water quality for the Selangor River from nine stations along the main stream, which concludes that water has been highly polluted (index 5) immediately downstream of station 02 Selangor River before confluence with Kubu River due to high concentration of microorganisms and immediately downstream of station 06 Selangor River before confluence with Batang Kali River due to high concentrations of microorganisms and suspended particles, was verified. Mineral micropollutants were found to gradually pollute the stream water, ranging from the unpolluted water (index 1) in the upstream to the bad quality (index 4) in the downstream area.

A study of the impacts of anthropogenic activities on the distribution and biodiversity of benthic macroinvertebrates and water quality of the Langat River (Peninsular Malaysia) was conducted. Four pristine stations from the upstream and 4 stations at the downstream receiving anthropogenic impacts were selected along the river. For 4 consecutive months (March-June 1999), based on the Malaysian DOE (Malaysia Environmental Quality Report 2000, Department of Environment, Ministry of Science, Technology and Environment Malaysia. Maskha Sdn. Bhd. Kuala Lumpur, 86pp; Malaysia Environmental Quality Report 2001, Department of Environment, Ministry of Science, Technology and the Environment Malaysia) water quality index classes, the upstream stations recorded significantly (Po0:05) higher Biological Monitoring Working Party scores and better water quality indices than those of the downstream. The total number of macrobenthic taxa and their overall richness indices and diversity indices were significantly (Po0:05) higher at the upstream stations (54 taxa) than at the downstream stations (5 taxa). The upstream of the Langat River was dominated by Ephemeroptera and chironomid dipterans while other orders found in small quantities included Trichoptera, Diptera, Plecoptera, Odonata, Ephemeraptera, Coleoptera, and Gastropoda. On the other hand, the downstream of the river was mainly inhabited by the resistant Oligochaeta worms Limnodrilus spp. and Branchiodrilus sp. and Hirudinea in small numbers. The relationships between the physicochemical and the macrobenthic data were investigated by Pearson correlation analysis and multiple stepwise regression analysis. These statistical analyses showed that the richness and diversity indices were generally influenced by the total suspended solids and the conductivity of the river water. This study also highlighted the impacts of anthropogenic land-based activities such as urban runoff on the distribution and species diversity of macrobenthic invertebrates in the downstream of the Langat River. The data obtained in this study supported the use of the bioindicator concept for Malaysian rivers. Some sensitive (Trichopteran caddisflies and Ephemeraptera) and resistant species (Oligochaeta such as Limnodrilus spp.) are identified as potential bioindicators of clean and polluted river ecosystems, respectively, for Malaysian rivers. r 2005 Elsevier Inc. All rights reserved.

Measurements of reflectance in visible and near-infrared spectral regions were made on detached leaves of two crop species of different leaf morphology, structure, and water content (peanut and wheat) throughout progressive desiccation. Relative water content (RWC) was well correlated with water index (WI) but even better with the ratio of WI and normalized difference vegetation index. RWC was also significantly