Influence of hydrogeochemical processes on temporal changes in groundwater quality in a part of Nalgonda district, Andhra Pradesh, India

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Environmental Earth Sciences ISSN 1866-6280Volume 65Number 4 Environ Earth Sci (2012) 65:1203-1213DOI 10.1007/s12665-011-1368-2

Influence of hydrogeochemical processes ontemporal changes in groundwater qualityin a part of Nalgonda district, AndhraPradesh, India

R. Rajesh, K. Brindha, R. Murugan &L. Elango

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ORIGINAL ARTICLE

Influence of hydrogeochemical processes on temporal changesin groundwater quality in a part of Nalgonda district,Andhra Pradesh, India

R. Rajesh • K. Brindha • R. Murugan •

L. Elango

Received: 2 March 2011 / Accepted: 17 September 2011 / Published online: 8 October 2011

� Springer-Verlag 2011

Abstract Geochemical processes that take place in the

aquifer have played a major role in spatial and temporal

variations of groundwater quality. This study was carried out

with an objective of identifying the hydrogeochemical pro-

cesses that controls the groundwater quality in a weathered

hard rock aquifer in a part of Nalgonda district, Andhra Pra-

desh, India. Groundwater samples were collected from 45

wells once every 2 months from March 2008 to September

2009. Chemical parameters of groundwater such as ground-

water level, EC and pH were measured insitu. The major ion

concentrations such as Ca2?, Mg2?, Na?, K?, Cl-, and SO42-

were analyzed using ion chromatograph. CO3- and HCO3

-

concentration was determined by acid–base titration. The

abundance of major cation concentration in groundwater is as

Na? [ Ca2? [ Mg2? [ K? while that of anions is

HCO3- [ SO4

2- [ Cl- [ CO3-. Ca–HCO3, Na–Cl, Ca–

Na–HCO3 and Ca–Mg–Cl are the dominant groundwater

types in this area. Relation between temporal variation in

groundwater level and saturation index of minerals reveals the

evaporation process. The ion-exchange process controls the

concentration of ions such as calcium, magnesium and

sodium. The ionic ratio of Ca/Mg explains the contribution of

calcite and dolomite to groundwater. In general, the geo-

chemical processes and temporal variation of groundwater in

this area are influenced by evaporation processes, ion

exchange and dissolution of minerals.

Keywords Hard rock � Saturation Index � PHREEQC �Evaporation � Dissolution of minerals

Introduction

Groundwater chemistry of a region is generally not homo-

geneous and it is controlled by geochemical processes, flow

and recharge processes, evaporation, evapotranspiration and

possible presence of contamination sources. Identification of

various geochemical processes will help to understand the

causes for changes in water quality due to the interaction with

aquifer material, especially in weathered rock formations.

Hydrogeochemical studies in turn assist in planning man-

agement and remedial measures to protect aquifers that are

contaminated by natural and anthropogenic activities. Thus,

detailed knowledge on geochemical process that control

groundwater chemistry is very essential to understand and

deal with the groundwater related issues. The cause for the

changes in groundwater quality by anthropogenic activity

like agriculture is also an important issue in arid and semiarid

region. The geochemical properties of groundwater depend

on the chemistry of water in the recharge area as well as on

the different geological processes that take place in the

subsurface. The groundwater chemically evolves due to the

interaction with aquifer minerals or by the intermixing

among the different groundwater reservoirs along the flow

path in the subsurface (Domenico 1972; Wallick and Toth

1976). Jalali (2005) reported that the dissolution of carbonate

minerals, cation exchange and weathering of silicates control

the groundwater chemistry in semiarid region of western

Iran. Martinez and Bocanegra (2002) indicated that cation

exchange and calcite equilibrium are the important hydrog-

eochemical processes that control the groundwater compo-

sition. Hydrochemical processes such as dissolution,

weathering of carbonate minerals and ion exchange are

responsible for groundwater quality in Delhi, India (Kumar

et al. 2006). Singh et al. (2008) indicated the impact of

mining allied activities on groundwater quality in the upper

R. Rajesh � K. Brindha � R. Murugan � L. Elango (&)

Department of Geology, Anna University,

Chennai 600025, India

e-mail: [email protected]; [email protected]

123

Environ Earth Sci (2012) 65:1203–1213

DOI 10.1007/s12665-011-1368-2

Author's personal copy

catchment of Damodar River basin, India. Even though there

are several studies on hydrogeochemical processes in the

arid region of alluvial and basaltic terrain no major research

has been carried out in arid regions of granitic terrain.

Implication of irrigation activity, evaporation and geo-

chemical processes of granitic aquifers need to be under-

stood. The granitic terrain of Archean age found in most part

of the central southern India is one such area with arid cli-

mate and irrigation activity. The present study was carried

out in granitic terrain of part of Nalgonda district, Andhra

Pradesh, India. The Nalgonda district in South India is well

known for high concentration of fluoride in groundwater

(Rao 1991). Influence of aquifer materials, availability of

fluoride rich minerals and intense weathering processes have

accentuated the release of fluoride from rocks and soils to

groundwater under the alkaline environment in Wallipalli

watershed, Nalgonda district, Southern India (Reddy et al.

2010). Hydrogeochemical exploration for targeting uncon-

formity related uranium mineralization in Kurnool Group

sediments located southeast of Nalgonda district was carried

out by Singh et al. (2002). Other studies in this area con-

centrated only on fluoride, nitrate (Brindha et al. 2010, 2011)

and bromide (Brindha and Elango 2010) concentration in

groundwater. However, no research had been carried out to

identify the hydrogeochemical processes based on regular

monitoring of groundwater level over space and time. Hence,

the present study was carried out in a part of Nalgonda dis-

trict, Andhra Pradesh (Fig. 1), with an objective of identi-

fying the influence of hydrogeochemical processes on

temporal changes in groundwater quality.

Materials and methods

The geology of the region was studied by numerous geo-

logical field visits. The rock types were identified by

megascopic observation of outcrops and well sections.

Based on these field investigations the geological map

obtained from Geological Survey of India was modified.

The subsurface geology and intensity of weathering was

studied by the inspection of large diameter unlined wells.

The thicknesses of soil zone and weathered granite were

measured in the vertical section of this large diameter

wells. Further two 60-m deep borehole logs were acquired

from Atomic Minerals Division, India. Groundwater sam-

ples were collected once every two months from March

2008 to September 2009 from 45 sampling wells (Fig. 2)

which were selected on the basis of a detailed well

inventory survey. About 450 samples were collected from

open wells and bore wells during the monitoring period.

Groundwater levels in these wells were measured using a

water level recorder (Sonalist 101). Chemical parameters

such as pH, electrical conductivity (EC) and temperature of

the groundwater samples were measured in the field using

portable multiparameter instrument (YSI 556). Ground-

water samples were collected in clean polyethylene bottles

of 600 ml capacity. The sampling bottles were soaked in

1:1 diluted HCl solution for 24 h prior to sampling and

then washed with distilled water. They were washed again

before each sampling with the filtrates of the sample. In the

case of bore wells, water samples were collected after

pumping the water for about 10 min. In the case of open

Fig. 1 Location of the study

area

1204 Environ Earth Sci (2012) 65:1203–1213

123


wells care was taken to collect the samples 30 cm below

the water table using a depth sampler. Samples collected

were transported to the laboratory and filtered using

0.45 lm Millipore filter paper for further analysis. The

major cations and anions such as Na?, K?, Ca2?, Mg2?,

Cl- and SO42- of groundwater samples were determined

using Metrohm 861 advanced compact ion chromatograph

using appropriate standards. The concentration of CO3-

and HCO3- were determined by titrating against H2SO4 as

per standard method (APHA 1995). The quality of the

analysis was ensured by standardization using blank, spike

and also with duplicate samples. Further accuracy of the

chemical analysis was verified by calculating ion balance

error which was generally within 5%. Soil samples were

collected near the sampling wells in May 2009 at a depth of

30 cm from ground surface. CaCO3 of the soil samples

were determined by acidimetric titration method (Menon

1979). TDS (Total Dissolved Solids) for Gibbs diagram

was calculated by using the formula TDS = EC 9 0.64.

The geochemical data were processed using PHREEQC 2

(Parkhurst and Appelo 1999) to determine the saturation

index (SI) of minerals and evaporation modeling.

Description of the study area

The study area (Fig. 1) is located at a distance of about

135 km ESE of Hyderabad. The southeastern side of the

study area is surrounded by the Narajuna Sagar reservoir

and the southern side of the area is partly bounded by

Pedda Vagu River. The northern boundary is bounded by

Gudipalli Vagu River. This area experiences arid to

semiarid climate. The study area goes through hot climate

during the summer (March–May) with a temperature

ranging from 30 to 46.5�C and in winter (November–Jan-

uary) it varies between 16 and 29 Æ C. The average annual

rainfall in this area is about 1,000 mm occurring mostly

during southwest monsoon (June–September). Paddy is the

principle crop grown in this area while other crops include

sweet lime, castor, cotton, grams and groundnut. Drip

irrigation is practiced in this area especially for sweet lime.

The commercial crops like chilies, cotton and groundnut

are also grown in this area mostly by using groundwater.

Geology and hydrogeology

The topography derived from SRTM (Shuttle Radar

Topography Mission) data is shown in Fig. 3. The topog-

raphy of the area comprising of an undulating terrain has a

maximum elevation of 348 m on northwestern side and

minimum elevation of 170 m on the eastern side. In gen-

eral, the ground surface slopes towards southeast direction.

There are several small hillocks in this area with height

ranging from 100 to 200 m. The surface runoff has resulted

into the development of dendritic to sub-dendritic drainage

pattern in this area. The geological map of the study area

was prepared after GSI (1995). This primarily comprises of

granite and granitic gneisss (Fig. 4). These rocks are gen-

erally medium to coarse-grained. These rocks are traversed

by numerous dolerite dykes and quartz veins. The granitic

rocks are intensely weathered and the thickness of weath-

ered zone ranges from 4 to 15 m. Calcareous material like

calcrete was observed in the weathered zone of several

large diameter wells. In certain regions calcrete was also

observed in ground surface and rock exposures. Occur-

rence of calcrete and nodular forms of calcrete was also

reported from the neighboring watershed by Reddy et al.

Fig. 2 Location of monitoring

wells

Environ Earth Sci (2012) 65:1203–1213 1205

123


(2010). The Srisailam Formation is the youngest member

of the Cuddapah supergroup, directly over the basement

granite with a distinct unconformity. The quartzite of Sri-

sailam Formation is exposed in the southeastern part of the

study area. The meta sediments of Srisailam Formation

which include pebbly-gritty quartzite, shale, dolomitic

limestone, intercalated sequence of shale-quartzite and

massive quartzites.

The top soil, weathered rock and fractured rock acts as

an unconfined aquifer in this area. The pore spaces are

developed in the weathered portions to form potential

water-bearing zones. There are a number of wells in this

area which supply water for domestic and agricultural

purposes. The depth of the dug wells ranges from 1.45 m to

20 m below ground level. Thus most of the wells tap

groundwater is from the weathered and fractured zone. The

diameter of the dug wells ranges from 2 to 5 m. The bore

wells were generally of 15 cm diameter and they were of

depth greater than 10 m. The borehole data of a few wells

are shown in Fig. 5. This figure shows the lithology of open

wells in which the thickness of soil and weathered zone

were measured during the field investigation. However, the

boreholes in the quartzite region drilled for exploratory

purpose by the Indian Atomic Minerals Division are of

60 m deep. Rainfall is the major source of groundwater

recharge in this area. The groundwater level fluctuates

Fig. 3 Topography

Fig. 4 Geology


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between 0 to 12 m and the average fluctuation is by about

6 m during 2008–2009. Sometimes during extreme sum-

mer few wells become completely dry. Out of 450 mea-

surements made in 45 wells over ten visits, 8% of

measurements indicated dry condition. In general ground-

water flows towards the southeastern direction of the study

area. The hydraulic conductivity of the area is 2.2–15.1

m/day. The specific yield of the aquifer ranges from 0.1 to

0.15. Even though there are several intrusives in this area,

they are not functioning as a barrier due to the high

intensity of weathering. The groundwater level of open

wells located on both sides of an intrusive rock was com-

pared and it was found to comply with the fact that these

intrusive do not play a significant role as a barrier (Fig. 6).

This figure also show similar trend in EC of groundwater of

open wells across the dolerite intrusive.

Results and discussion

The minimum and maximum values of chemical parame-

ters and concentration of major ions measured in ground-

water of this area are given in Table 1. The pH of the

groundwater samples of this area ranges from 6.9 to 7.8.

Thus groundwater of this area is generally alkaline in nat-

ure. EC of the groundwater samples ranges from 375 to

2500 lS/cm. The general order of dominance of cations in

the groundwater of the study area is Na? [ Ca2? [Mg2? [ K? while that for anions is HCO3

- [ SO4-2 [

Cl- [ CO3-. Ca–HCO3, Na–Cl, Ca–Na–HCO3 and

Ca–Mg–Cl are the dominant water types in this area based

on the Piper (1944) classification (Fig. 7). According to

Gibbs diagram (Gibbs 1970) rock water interaction is

responsible for the chemical composition of the ground-

water (Fig. 8). The temporal variation of chemical com-

position, groundwater level and rainfall of monitoring wells

are shown in Fig. 9. This figure indicates that the concen-

tration of ions vary with respect to time. The rainfall

recharge and other hydrogeological processes are the cau-

ses for this variation.

Hydrogeochemical processes

The results from the hydrochemical data were used to

identify the geochemical processes and mechanisms

responsible for the groundwater chemistry of the study

area. The identified processes are explained in detail in the

following sections.

Fig. 5 Lithologs of selected boreholes


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Evaporation process

In general, the evaporation process would cause an increase

in concentration of all mineral species in water. The plot of

Na versus Cl (Fig. 10) and Ca versus HCO3 (Fig. 11) of

groundwater collected from the study area was compared

with the evaporation line of groundwater of lowest ionic

concentration (well no. 3 in November 2008). These plots

indicate that groundwater chemistry of this area is con-

trolled by evaporation process. Direct evaporation of

groundwater is possible as the region has many number of

large diameter open wells where groundwater table occur

at shallow depths.

Ion-exchange process

In order to evaluate the ion-exchange process in this

region, a plot of Na–Cl versus Ca ? Mg–HCO3–SO4 was

prepared (Fig. 12). If ion exchange is the dominant process

in the system the points will form a line with a slope of -1

which can be explained by the following reaction (1)

(Rajmohan and Elango 2004).

Ca2þðMg2þÞ þ NaþClay$ 2Naþ þ CaðMgÞClay ð1Þ

Similar results were observed for the groundwater of

this area. The plot shows that the points give a line with a

slope of -0.8794. This confirms that Ca2?, Mg2? and Na?

concentrations are interrelated through ion exchange

Fig. 6 Temporal variations in

groundwater level and EC in

wells across the intrusive

Table 1 Minimum and maximum values of physical and chemical

parameters

Parameters Minimum Maximum

Groundwater level (m bgl) 0 14.6

pH 6.9 7.8

EC (lS/cm) 375 2,500

Na (mg/l) 21 470

Ca (mg/l) 15 409

Mg (mg/l) 4 94

K (mg/l) BDL 317

CO3 (mg/l) 0 48

HCO3 (mg/l) 44 592

SO4 (mg/l) 1 405

Cl (mg/l) 0 355


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(Rajmohan and Elango 2004; Elango et al. 2003; Fisher

and Mullican 1997).

Silicate weathering

Silicate weathering is one of the major processes that

release Na and K in groundwater in aquifers of plutonic

rocks. This is likely to be the major process that contributes

Na and K to groundwater. Sample points below 1:1 line in

Na versus Cl scatter diagram (Fig. 13) indicate that they

are derived by silicate weathering (Stallard and Edmond

1983). Similarly Ca ? Mg Versus Total cations (TC)

scatter diagram (Fig. 14) indicates that most of the samples

lie below the 1:1 line. This also indicates the contribution

Fig. 7 Geochemical facies of

groundwater

Fig. 8 Mechanism of

controlling groundwater

chemistry


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Fig. 9 Temporal variations of chemical composition, groundwater

level and rainfall

Fig. 10 Relationship of Na versus Cl along with evaporation line of

groundwater with lowest ionic concentration

Fig. 11 Relationship of Ca versus HCO3 along with evaporation line

of groundwater with lowest ionic concentration

Fig. 12 Relationship between Na–Cl and Ca?Mg–HCO3–SO4

Fig. 13 Relationship between Na and Cl

Fig. 14 Relationship between Ca ? Mg and Total Cation (TC)


123


of Na and K to groundwater by silicate weathering. This

may be explained by the following weathering reaction (2).

Similar processes of weathering of pyroxene, amphibole

and calcic feldspar minerals, which are common in basic rocks

that are easily weatherable, controlled the concentration of

these ions in groundwater in certain other parts of southern

India and in Himalyan river basin (Jacks 1973; Bartarya

1993).

Dissolution of minerals

Mineral equilibrium calculations for groundwater are use-

ful in predicting the presence of reactive minerals in the

groundwater system and estimating the mineral reactivity

(Deutsch 1997). The SI of mineral is calculated using

SI = (IAP/Ks) (Appelo and Postma 1996), where IAP is

the ion activity product and Ks is the solubility product of

the mineral.

SI of minerals is very helpful for evaluating the

groundwater chemistry and to see if it is controlled by

equilibrium with solid phases (Appelo and Postma 1996).

If SI \ 0, the water is undersaturated, if SI = 0, the water

is in equilibrium with the mineral and if SI [ 0, the water

is oversaturated. The SI of all minerals were calculated

using PHREEQC by assuming that the groundwater of

lowest concentration of ions is evaporated. It was found

that the SI of calcite and dolomite increases to more than

zero when water is evaporated by 40 and 70%, respectively

(Fig. 15). All the other minerals do not reach saturation

level even after 100% of evaporation. It is expected that

calcite and dolomite may have been deposited in the soil

zone and well sections due to evaporation. Presence of such

calcareous material was noted in the well sections of this

area and also in the neighboring watershed of similar

geological condition by Reddy et al. (2010). The CaCO3%

of 26 soil samples collected from this area ranges from 0.4

to 27.3%. Jacks and Sharma (1995) also reported the

occurrence of dolomitic carbonates in this area. They also

observed preferential formation of calcite in the chromus-

ters while dolomite occurs only in the Rhodustalfs. The

soils in the Nalgonda region are of moderately to gently

sloping Ustrothents and Rhodustalfs (Gajbhiye and Mandal

Fig. 15 Calculated changes in SI of minerals during evaporation of

groundwater with lowest ionic concentration

Fig. 16 Temporal variations in rainfall, groundwater level and

mineral saturation index

2NaAlSi3O8 þ 2H2CO3 þ 9H2O ) Al2Si2O5 OHð Þ4Albiteð Þ Silicate weatheringð Þ Kaoliniteð Þ þ 2Naþ þ 4H4SiO4 þ 2HCO�3

ð2Þ


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2000). Hence, it is reasonable to assume that these minerals

are reactive in groundwater environment and they can

control solution concentration. The SI of calcite and

dolomite of groundwater of this area vary with time.

During recharge of rainfall, the groundwater level increases

and SI of calcite and dolomite decreases (Fig. 16). During

dry periods, when the groundwater level decreases, the SI

of these minerals increases which indicates the process of

evaporation. That is, the recharge of rainwater dissolves

these minerals deposited during the preceding dry months

in the soil zone, which increases the SI of minerals in

groundwater. If the rainfall continues for an extended

period, the saturation levels continues for an extended

period, the saturation levels of minerals decrease in

groundwater. Similar observation was made in a few other

regions of south India (Elango and Ramachandran 1991;

Rajmohan and Elango 2004). As it is an arid dry land

where irrigation is practiced with both surface and

groundwater, the water used for irrigation undergoes

evaporation leading to increase in concentration of ions.

This evaporation enriched irrigated water enters the

groundwater zone as recharge, which is pumped again for

irrigation. Thus pumping of groundwater for irrigation and

its evaporation from the irrigated area lead to increase in

concentration of salts especially carbonates in the soils.

Modeling of evaporation processes by PHREEQC also

indicates that water reaches the saturation level only for the

minerals of Calcite and Dolomite (Fig. 16).

The study of the Ca/Mg ratio of groundwater from this

area also supports the dissolution of calcite and dolomite

(Fig. 17). That is, if the ratio of Ca/Mg = 1, dissolution of

dolomite should occur, whereas a higher ratio is indicative

of greater calcite contribution (Maya and Loucks 1995;

Jacks and Sharma 1995). Higher Ca/Mg molar ratio ([2)

indicates the dissolution of silicate minerals, which con-

tributes calcium and magnesium to groundwater. In this

plot, the points closer to the line (Ca/Mg = 1) indicate the

dissolution of dolomite. Most of the samples which have a

ratio between 1 and 2 indicate the dissolution of calcite.

Those with values greater than 2 indicate the effect of

silicate minerals (Fig. 17).

Conclusion

The geochemical processes of groundwater in a part of

Nalgonda district, Andhra Pradesh, India were assessed by

systematic collection and analysis of groundwater samples

from March 2008 to September 2009. The dominant

hydrogeochemical facies of groundwater is Ca–HCO3,

Na–Cl, Ca–Na–HCO3 and Ca–Mg–Cl. Weathering and

dissolution of silicate minerals control the concentration of

major ions such as Na?, Ca2?, Mg2? and K? in ground-

water of this area. Ion exchange process also controls

the concentration of Ca2? and Na?. Relation between

groundwater level and saturation index of minerals reveals

the importance of evaporation process on groundwater

ionic concentration and irrigation practice in this arid

region. The temporal variation in groundwater chemistry of

this area is principally controlled by a combination of

factors such as evaporation, ion exchange, silicate weath-

ering and dissolution of minerals. The variation in

groundwater chemistry helped in the identification of

geochemical processes in this hard rock region.

Acknowledgments The authors would like to thank the Board of

Research in Nuclear Sciences, Department of Atomic Energy, Gov-

ernment of India (Grant No. 2007/36/35) for their financial support.

Thanks are due to Atomic Mineral Division for providing the litholog

numbers, YLR 31 and YLR 14. The Department of Science and

Technology’s Funds for Improvement in Science and Technology

scheme (Grant No. SR/FST/ESI-106/2010) and University Grants

Commission’s Special Assistance Programme (Grant No. UGC DRS

II F.550/10/DRS/2007(SAP-1)) are also acknowledged as the ana-

lytical facilities created from these funds were used to carry out part

of this work.

References

APHA (1995) Standard methods for the examination of water and

wastewater, 19th edn. American Public Health Association,

Washington, DC

Appelo CA, Postma D (1996) Geochemistry, groundwater and

pollution. Balkema, Rotterdam

Bartarya SK (1993) Hydrochemistry and rock weathering in a sub-

tropical lesser Himalayan river basin in Kumaun, India. J Hydrol

146:149–174

Brindha K, Elango L (2010) Study on bromide in groundwater in

parts of Nalgonda district, Andhra Pradesh. Earth Sci India

3(1):73–80

Brindha K, Murugan R, Rajesh R, Elango L (2010) Natural and

anthropogenic influence on the fluoride and nitrate concentration

of groundwater in parts of Nalgonda district, Andhra Pradesh,

India. J Appl Geochem 12(2):231–241

Brindha K, Rajesh R, Murugan R, Elango L (2011) Fluoride

contamination in groundwater in parts of Nalgonda district,

Andhra Pradesh, India. Environ Monit Assess 172:481–492

Deutsch WJ (1997) Groundwater geochemistry: fundamentals and

application to contamination. CRC, Boca Raton

Domenico PA (1972) Concepts and models in groundwater hydrol-

ogy. McGraw Hill, New York

Fig. 17 Relationship between Ca/Mg versus Total Cation (TC)


123


Elango L, Ramachandran S (1991) Major ion correlations in

groundwater of a coastal aquifer Journal of Indian Water

Resources Society 11:54–57

Elango L, Kannan R, Senthilkumar M (2003) Major ion chemistry

and identification of hydrogeochemical processes of ground

water in a part of Kancheepuram district, Tamil Nadu, India.

Environ Geosci 10(4):157–166

Fisher SR, Mullican WF (1997) Hydrogeochemical evolution of

sodium-sulfate and sodium-chloride groundwater beneath the

northern Chihuahua desert, Trans-Pecos, Texas, USA. J Hydro-

geo 5(2):4–16

Gajbhiye, KS, Mandal C (2000) Agro-Ecological Zones, their Soil

Resource and Cropping Systems, Status of Farm Mechanization

in India, Cropping Systems, Status of Farm Mechanization in

India, pp 1–32

Gibbs RJ (1970) Mechanisms controlling world water chemistry.

Science 170:795–840

GSI (1995) Geological Survey of India’s Geology and minerals map

of Nalgonda district, Andhra Pradesh, India

Jacks G (1973) Chemistry of groundwater in a district in Southern

India. J Hydro 18:185–200

Jacks G, Sharma VP (1995) Geochemistry of calcic horizons in

relation to hillslope processes, southern India. Geoderma

67:203–214

Jalali M (2005) Major ion chemistry of groundwaters in the Bahar

area, Hamadan, Western Iran. J Env Geo 47:763–772

Kumar M, Ramanathan AL, Rao MS, Kumar B (2006) Identification

and evoluation of hydrogeochemical processes in the ground-

water environment of Delhi, India. J Env Geo 50:1025–1039

Martinez DE, Bocanegra EM (2002) Hydrogeochemistry and cation

exchange processes in the coastal aquifer of Mar Del Plata.

Argentina. J Hydrogeo 10:393–408

Maya AL, Loucks MD (1995) Solute and isotopic geochemistry and

groundwater flow in the Central Wasatch Range. UtahJ Hydro

172:31–59

Menon RG(1979) Physical and chemical methods of soil analysis, A

laboratory manual prepared for the use of technicians working in

the soil laboratories of the FAO/UNDP/URT project ‘‘National

Soil Service’’ (English), FAO, Rome (Italy), Agriculture

Department 188

Parkhurst DL, Appelo CAJ (1999) A computer program for speci-

ation, batch-reaction, one-dimensional transport and inverse

geochemical calculations: Water resource investigation, US

Geological Survey, a report, pp 99–4259

Piper AM (1944) A Graphical interpretation of water- analysis. Trans

Am Geophys Union 25:914–928

Rajmohan N, Elango L (2004) Identification and evolution of

hydrogeochemical processes of groundwater environment in an

area of the Palar and Cheyyar River Basins, Southern India.

J Env Geo 46:47–61

Rao NVRM (1991) Hydro-geochemistry and fluoride in Nalgonda

district of Andhra Pradesh, India. International symposium on

applied geochemistry. Osmania University, Hyderabad,

pp 255–261

Reddy DV, Nagabhushanam P, Sukhija BS, Reddy AGS, Smedly PL

(2010) Fluoride dynamics in the granitic aquifer of the Waila-

pally watershed, Nalgonda District, India. J Chem Geo

269:278–289

Singh RV, Sinha RM, Bisht BS, Banerjee DC (2002) Hydrogeo-

chemical exploration for unconformity-related uranium miner-

alization: example from Palanudu sub-basin, Cuddapah Basin,

Andhrapradesh, India. J Geo Exp 76:71–92

Singh AK, Mondal GC, Kumar S, Singh TB, Tewary BK, Sinha A

(2008) Major ion chemistry, weathering processes and water

quality assessment in upper catchement of Damoda River basin,

India. J Env Geo 54:745–758

Stallard RF, Edmond JM (1983) Geochemistry of the Amazon: the

influence of geology and weathering environment on the

dissolved load. J Geophy Res 88:9671–9688

Wallick EI, Toth J (1976) Methods of regional groundwater flow

analysis with suggestions for the use of environmental isotope

and hydrochemical data in groundwater hydrology, pp 37–64


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Influence of hydrogeochemical processes on temporal changes in groundwater quality in a part of Nalgonda district, Andhra Pradesh, India