Hydrology, hydrogeologyand hydrochemistry of wetlands:a case study in IzmirBird Paradise, TurkeyA. Melis Somay Æ Sevki Filiz

Abstract Izmir Bird Paradise is one of the mostvaluable wetlands in Turkey, but this area is nowbeing threatened by the drying out of marshes andwater pollution. This wetland consists of twoecosystems: fresh- and saltwater. The recharge ofmarshes is from rainfall, the Gediz River andgroundwater from Can Suyu Pond. The water type ofthe river is Ca–Mg–Na-HCO3–SO4, whereas thegroundwater is a Na-Cl water type. The reasons forthe drying are long-term drought (evapotranspira-tion at 894 mm is >> rainfall at 546 mm), andexcessive pumping of groundwater and seawaterintrusion into Menemen Plain. Therefore, an addi-tional freshwater resource is necessary. This watercan be supplied from the limestone levels of Neo-gene sedimentary rocks in and around Izmir BirdParadise that have a Ca-HCO3 water type. Waterpollution levels were also analysed. In the freshwaterecosystem Cd, Cr, Fe, Mn, Ni, Pb, Sb and Zn values,in the open channel in Izmir Bird Paradise Sb, Fe, Niand Cd values, and in the river Fe, Pb and Sb valuesexceed the TSE 266 and EPA 2000 standardsprobably due to agricultural and industrial sources.

Keywords Bird Paradise Æ Hydrochemistry ÆHydrogeology Æ Izmir Æ Turkey Æ Wetland

Introduction

Hydrology is probably the single most important deter-minant for the establishment and maintenance of specifictypes of wetlands and wetland processes. Water is almost

always the major source of nutrients to wetlands (Eser andRasen 1999). Wetlands receive surface water inputs fromstreams (surface runoff), precipitation and overland flow,and subsurface water inputs from surface infiltration,stream hyporheic zones and groundwater (Mann andWetzel 2000). Hydrochemical processes in coastal aquifersare important in sustaining water quality conditions infreshwater wetlands. As such, wetlands are importanthabitats that contribute to the biodiversity of the coastalzone: it is important that these processes are understoodand maintained (Malcolm and Soulsby 2001).Izmir Bird Paradise is located in the southern part ofLower Gediz Basin, which includes the Menemen Plain andIzmir (Fig. 1), and encompasses an area of approximately8,000 ha. Izmir Bird Paradise is one of the most valuablewetlands in Turkey caused by the Gediz River, and it formsfresh- and saltwater ecosystems that provide habitats for205 bird species (Siki 1999) and 308 vegetation species.Izmir Bird Paradise is included in the 1997 RamsarConvention for the protection of wetland areas.Until now, there has been scarce hydrogeological dataabout this wetland. Thus, this study is the first compre-hensive hydrogeological investigation, which was done inand around Izmir Bird Paradise, reporting on the hydro-geological, hydrological and hydrochemical data of IzmirBird Paradise.The specific objectives of this study are (1) the preliminaryinvestigation and interpretation of the hydrochemicalproperties of the fresh- and saltwater ecosystems, (2) tosuggest an alternative freshwater source for the dried reedsin Izmir Bird Paradise, and (3) to determine the waterpollution level and sources in and around Izmir BirdParadise.

Methodology

A total of 22 water samples from different places in andaround Izmir Bird Paradise were collected during 2000.The water samples were analysed according to APHA-AWWA-WCPF (1975), APHA-AWWA-WCPF 3110 (1992)and TSE 266). AQUACHEM 3.7 computer code was used toevaluate the hydrogeochemical data.Determination of pH, conductivity and both major andminor ions were made in the laboratory using theanalytical methods shown in Table 1.

Received: 9 April 2002 / Accepted: 26 August 2002Published online: 8 October 2002ª Springer-Verlag 2002

A.M. Somay (&) Æ S. FilizDokuz Eylul University,Geological Engineering Department,35100, Bornova, Izmir, TurkeyE-mail: melis.somay@deu.edu.trFax: +90-232-3887865

Original article

DOI 10.1007/s00254-002-0697-6 Environmental Geology (2003) 43:825–835 825

Climate and rainfall

Menemen Plain is dry–subhumid, with a third mesother-mal season of deficiency, with a large seasonal surplus anda temperature-efficiency regime third mesothermal(C1B1

3S2W2b13) according to the Thorntwaite classifica-

tion system (1948). The dry season occurs in summer(May through October) and the wet season occurs inwinter (November through April). According to the data ofKoy Hizmetleri Menemen Research Institute, the meanyearly temperature has been �16.9 �C in a 45-year period.June is the hottest month, January is the coolest. Averageyearly rainfall in Menemen Plain is estimated to be about546 mm. Average yearly actual evapotranspiration is about894 mm according to the Thorntwaite method. The mainfeatures regarding rainfall, temperatures, evaporation,relative humidity and wind are presented in Table 2Evapotranspiration was calculated using the Thorntwaitemethod (Table 3) and an evapotranspiration–rainfalldiagram is shown in Fig. 2.According to Fig. 2a, the amount of rainfall is greater thanpotential evapotranspiration in January, February andMarch; therefore, potential evapotranspiration is equal toreal evapotranspiration. Excessive water from rainfall(water surplus) recharges the surface and groundwater.From Fig. 2b, it can be seen that soil moisture utilizationresponds to water deficiency in April, May and June.Potential evapotranspiration is greater than rainfall;

Fig. 1Location map of the study area

Tab

le2

Cli

mat

ed

ata

bet

wee

n19

54–

1999

inM

enem

enP

lain

(So

may

2000

)

Mo

nth

sI

IIII

IIV

VV

IV

IIV

III

IXX

XI

XII

An

nu

al

Rai

nfa

ll(m

m)

Ave

rage

92.5

71.8

65.3

42.0

27.2

6.3

33.

59.

632

.378

.311

4.5

546.

3D

aily

max

.79

.064

.083

.942

.044

.632

.321

.633

.972

.969

.411

9.8

75.8

119.

5D

ate

22.1

.98

20.2

.65

19.3

.62

5.4.

7816

.5.8

211

.6.8

64.

7.59

12.8

.71

9.9.

6615

.10.

7716

.11.

6324

.12.

6718

.11.

63T

emp

erat

ure

(�C

)A

vera

ge7.

98.

810

.915

.020

.024

.626

.926

.122

.217

.113

9.7

16.9

Max

.22

.826

.531

.633

.840

.242

.442

.044

.341

.439

.431

.325

.444

.3D

ate

22.1

.98

28.2

.95

31.3

.77

17.4

.94

25.5

.94

14.6

.95

22.7

.94

24.8

.58

12.9

.94

2.10

.92

1.11

.92

21.1

2.64

24.8

.64

Min

.–

7.6

–5.

6–

4.4

–1.

42.

86.

710

.710

.86.

01.

2–

0.2

–4.

5–

7.6

Dat

e18

.1.6

49.

2.76

14.3

.87

10.4

.97

4.5.

903.

6.90

4.7.

6430

.8.9

528

.9.5

631

.10.

7428

.11.

7323

.12.

6818

.01.

63T

ota

l45

.351

.579

.811

2.1

169.

622

5.8

267.

323

3.3

164.

610

0.6

56.2

44.6

1,55

1E

vap

ora

tio

n(m

m)

Dai

lym

ax.

20.2

19.0

15.1

13.6

13.7

15.5

18.0

15.5

11.2

11.5

12.1

13.2

20.2

Dat

e29

.1.6

410

.2.7

29.

3.63

5.4.

6428

.5.9

94.

6.99

22.7

.83

4.8.

858.

9.70

16.1

0.75

5.11

.74

25.1

2.73

29.1

.64

Rel

ativ

eh

um

idit

y(%

)A

vera

ge64

.461

.060

.256

.954

.147

.946

.047

.352

.858

.261

.965

.156

.3M

ax10

0.0

99.0

99.0

100.

099

.099

.098

.099

.010

0.0

100.

010

0.0

99.0

100.

0D

ate

1968

1999

1999

1963

1991

1991

1999

1999

1959

1955

1959

1999

1955

Min

.14

.014

.012

.010

.010

.06.

06.

09.

09.

011

.012

.013

.06.

0D

ate

1997

1998

1989

1998

1998

1996

1996

1996

1996

1996

1996

1996

1996

Win

dsp

eed

(m/s

)A

vera

ge3.

93.

83.

32.

72.

52.

62.

92.

72.

42.

42.

73.

63.

0D

irec

tio

nE

EE

EE

NW

EE

EE

EE

E

Table 1Analytical methods (APHA-AWWA-WCPF 1975, 1992)

Ions Analytical method

HCO3–, CO3

2–, Cl– VolumetricSO4

2– GravimetricNa+, K+, Ca2+, Mg2+ Atomic absorption spectrometerFe, Mn, Ni, Sb, Pb, Cd, Cr Atomic absorption spectrometer

Original article

826 Environmental Geology (2003) 43:825–835

therefore, there is a water deficiency from June to Sep-tember. From Fig. 2c, it can be seen that in November andDecember, potential evapotranspiration is equal to realevapotranspiration as the rainfall is greater than potentialevapotranspiration. Soil moisture is recharged by excesswater. Other water recharges the surface and groundwater.

Geology and hydrogeology

Sedimentary and volcanic formations outcrop in theMenemen Plain (Fig. 3). Upper Cretaceous Bornova Me-lange (Erdogan 1990), which forms the basement rock ofthe area and consists of sandstone–shale intercalations, isnot suitable for groundwater storage and recharge due toits low permeability and porosity. Bornova Melange is notexposed in Izmir Bird Paradise.

Neogene sedimentary rocks that contain limestone–claystone–clayey limestone alternately overlay the BornovaMelange with an unconformity. Limestone, which hasrelatively high permeability due to its porous and frac-tured structure, is a good aquifer for water. Clayey levels ofNeogene constitute the impermeable base of the aquifers.Neogene volcanic rocks, which are composed of tuff,agglomerates and andesites, overlay the Neogene sedi-mentary rocks. Although the primary porosity of volcanicrocks is very low, tectonic activity has resulted in sec-ondary porosity, which gives rise to a significant increasein permeability. Therefore, tuff and andesite are suitablerocks to recharge and store groundwater, and high qualitywaters can be supplied from these rocks in the MenemenPlain. However, Neogene volcanic rocks are not found inIzmir Bird Paradise.The Quaternary alluvium that consists of clayey, silty,sandy and gravely levels overlays all of these rocks with an

Table 3Thorntwaite water balance. T Temperature (�C); TI temperature indices; PE potential evapotranspiration (mm); CF correction factor; CPEcorrected PE (mm); P precipitation (mm); DS storage change; S storage; ETR real evapotranspiration (mm); WD water deficiency; EWexcessive water; RO runoff (mm); MR moisture ratio

Date Jan. Feb. March April May June July Aug. Sept. Oct. Nov. Dec. Total

T 7.9 8.8 10.9 15.0 20.0 24.6 26.9 26.1 22.2 17.1 13.0 9.7TI 2.0 2.4 3.3 5.3 8.2 11.2 12.8 12.2 9.6 6.4 4.2 2.7 80.1PE 15.6 18.9 27.7 48.9 81.5 117.9 138.2 131.0 98.2 61.7 37.9 22.5 799.9CF 0.9 0.8 1.0 1.1 1.2 1.2 1.3 1.2 1.0 1.0 0.9 0.8CPE 13.4 15.9 28.5 53.7 99.5 145.0 172.8 153.3 101.1 59.8 32.2 18.7 893.9P 92.5 71.8 65.3 42.0 27.2 6.3 3.0 3.5 9.6 32.3 78.3 114.5 546.3DS –42.0 0.0 0.0 –11.7 –72.3 –16.0 0.0 0.0 0.0 0.0 46.1 95.8S 100 100 100 88.3 16.0 0.0 0.0 0.0 0.0 0.0 46.1 142.0ETR 13.4 15.9 28.5 53.7 99.5 22.3 3.0 3.5 9.6 32.3 32.2 18.7 332.5WD 0.0 0.0 0.0 0.0 0.0 122.7 169.8 149.8 91.5 27.5 0.0 0.0 561.4EW 121 55.9 36.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 213.8RO 60.5 88.5 46.4 18.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 213.8MR 4.9 2.8 1.4 –0.1 –0.7 –0.9 –1.0 –1.0 –0.9 –0.5 1.1 4.1 9.2

Fig. 2Thorntwaite evapotranspiration–rainfall dia-gram in Menemen Plain

Original article

Environmental Geology (2003) 43:825–835 827

Original article

828 Environmental Geology (2003) 43:825–835

unconformity. Alluvium is the most suitable layer tosupply groundwater for drinking water and agriculturalpurposes in and around Izmir Bird Paradise because of itshigh permeability. Data of groundwater depths aroundIzmir Bird Paradise, which were measured by DSI inOctober 1980 and October 1998, are shown in Table 4.According to the October 1998 data, the general flowdirection of the groundwater is towards to the MenemenPlain (Fig. 3). This flow direction can be explained asseawater recharges the fresh groundwater. From 1980 to1998, groundwater depths declined by about 8–13 m(Table 4). Long-term drought and excessive pumping inthe study area have resulted in these large drawdowns ofthe water table in the unconfined aquifer of the coastalarea.The formation period of the Izmir Bird Paradise and theMenemen Plain, which is the delta of the Gediz River, allbegan at the same time. During the redistribution of soilscarried down the seaward-bound Gediz River (the same areaas today’s reedy area), these residues were deposited and,eventually, the reedy area blocked the one-time connectionbetween Izmir Bay and the Aegean Sea. Human interventionin 1863 helped to transform the bed of the Gediz River andhelped to shape the present Izmir Bird Paradise and provideboth salt- and freshwater ecosystems (Atis 1999).

Hydrochemistry

Izmir Bird Paradise consists of two ecosystems, fresh-and saltwater, according to hydrochemical data. The

freshwater ecosystem is made up of surface water,marshes and the Gediz River, and the groundwater isfrom Can Suyu Pond. The freshwater marshes receivetheir surface water inputs from Gediz River and rainfall.In addition, some marshes were destroyed in 1980 dueto construction of Kozluca Set and drainage work (Siki1999). It is worth highlighting that the freshwaterecosystem is salinized as a result of the change in of theGediz River bed from 1863, a long-term drought andseawater intrusion. On the other hand, the Lower GedizBasin’s delta contains one of the largest salt flats inTurkey. The leaching of salts during subsequent rainfallevents, in combination with evaporation losses, increasesthe concentrations of Na and Cl in the soil andgroundwater (Malcolm and Soulsby 2001). These effectshave also dried the reeds; consequently, the reedsrequire a freshwater source. In order to address this,initial treatments were conducted in Izmir Bird Paradiseby DSI (Devlet Su Isleri) in the Can Suyu Pond Project.A well was drilled in 1992 by DSI in Suzbeyli to supplyfreshwater to the reed beds. About 30 l/s supplies theIzmir Bird Paradise with a pipe of 5,800 m in length.This groundwater constitutes a natural pond in thewetland and is released to the reeds. However, due tothe insufficiency of this method, the Gediz River watersand irrigation wastewaters accumulate at Bedir Bridgeand they are released by a cover that was constructed byDSI (D9 cover). Although all these treatments have beendone, brining of the reeds still continues. The waterlevel of the marshes in the rainy season is about 80 cm,but in the dry season the reed beds are dried out due tolack of fresh water.The natural weirs, Homa, Kirdeniz and Cilazmak, and thesaltpans, e.g. Izmir Camalti Saltpan, constitute thesaltwater ecosystem.The water samples were taken from fresh- and saltwaterecosystems, from dug wells in the Neogene Hills, fromopen channels in and around Izmir Bird Paradise andfrom Gediz River (Fig. 4, Table 5). Some physical andchemical properties of these waters are shown in Table 6.

Fresh- and saltwater ecosystems

In the freshwater ecosystem measured pH values rangebetween 7.6 and 8.8 (slightly alkaline) for surface waterand 6.46 and 7.8 for groundwater. Measured surface waterconductivity values range between 651–36,100 lmhos/cm,and groundwater conductivity values range between 420–4,490 lmhos/cm.Hydrogeochemical facies were used to describe the bodiesof groundwater in an aquifer that differ in their chemicalcomposition. The facies are the function of lithology,solution kinetics and flow patterns of the aquifer (Back1966). Classification of waters depends on the principles ofthe IAH (International Association of Hydrogeologist)1979. Total equivalents of cations and anions were taken as100% and ions, as more than 20% (meq/l), were evaluatedin the classification.

Fig. 3Geological map of Menemen Plain and groundwater flow directionaround Izmir Bird Paradise. Modified from Somay and Filiz (2001b)

Table 4Groundwater depths data around Izmir Bird Paradise (Somay andFiliz 2001a)

Location Water depth 1980 Water depth 1998(m) (m)

Eski Mezarlik vicinity – –6.45Tuzcullu +2.20 –6.70Suzbeyli – –3.10Kucukkoy Farm – –9.60Cakirkuyu – –9.40Karadede – –8.00Yerli Alani – –3.75Karaburunbagi – –8.00Haci Huseyin wells – –6.20Seyrek well – –12.10Seyrek vicinity –1.20 –8.80Seyrek – –8.43Degirmen Hill – –8.45Degirmen Hill – –9.91Kesikkoy –1.80 –13.00Gunerli water store –0.35 –12.50South of Gunerli – –12.00Orta Koy (2825 DSI) –2.82 –15.40Musabey well –2.10 –12.40

b

Original article

Environmental Geology (2003) 43:825–835 829

Fig. 4Location map of the sample points

Table 5Sample names and locations ofthe water samples

Samplename

Location Samplename

Location

1 Dug well at Poyraz Hill 12 Gediz River (Maltepe)2 Dug well at Orta Hill 13 Gediz River (Old Bergama Bridge)3 Fault spring at Lodos Hill 14 Gediz River (Muradiye Bridge)4 Drinking water (Tasli Hills) 15 Gediz River (Akhisar Bridge)5 Drinking water of Maltepe

Village (Tasli Hills)16 Saltpan

6 Marshes 17 Saltpan7 Marshes 18 Open channel in front of the Visitor Centre8 Can Suyu Pond 19 Open channel in front of the Seyrek municipality9 Can Suyu Pond 20 Open channel east of the Maltepe Leather Zone

10 Bedir Bridge 21 Open channel in front of Maltepe village11 Bedir Bridge 22 Seawater

Original article

830 Environmental Geology (2003) 43:825–835

The water type of the marshes is Na-Cl both in the dry andrainy season. Although the marshes are recharged by rain-fall and groundwater, the amount of rainfall is lower thanevapotranspiration and the groundwater is already mixedwith seawater. These waters are ‘slightly saline–saline’according to TDS values, which can be reach 22,174 mg/l.The samples of river water were taken from the source ofthe Lower Gediz Basin to Maltepe, where the river is spillsout to the sea, and also from Bedir Bridge in Izmir BirdParadise in the rainy season. The water type is Na–Ca–Mg-HCO3–SO4 at Bedir Bridge; the others type are Ca–Mg–Na-HCO3–SO4. These waters are ‘fresh’ water according toTDS with a maximum of 871 mg/l.At Can Suyu Pond, the major cation is Na and the majoranion is Cl. This can be explained by the seawater rechargeinto the groundwater at Suzbeyli. This water is classified as‘saline’ by TDS values.The behaviour of the marshes and Can Suyu Pond closestto the coast is of interest. These points show a rise inconductivity (values reach 36,100 lmhos/cm) and in Clcontent (more than 10,000 mg/l). This feature, combinedwith the changes in the other ionic relationships such asMg/Ca ratio, rises from 0.508 to 1.317, and the Cl/HCO3

ratio increases from 1.858 to 48.047.A preliminary characterization, carried out using the Pipertriangular diagram, shown in Fig. 5, shows the differentgeochemistry of the sampled waters. This diagram showsthat marshes, Can Suyu Pond and the saltpans are a Na-Cltype; Gediz River is a Ca–HCO3 type and Bedir Bridgewater is a mixed water type.In the Schoeller semi-logarithmic diagram (Fig. 6a) it canbe seen that all the freshwater ecosystems show the samepeak with seawater and this can be explained by seawaterintrusion. In addition to the long-term drought, reeds aresalinized and need fresh water. Gediz River water plots atlower levels on the diagram due to the lack of seawaterinfluence (Fig. 6b).The evidence of seawater intrusion between fresh- andsaltwater is reflected in the Piper triangular diagramshown in Fig. 5 and the Schoeller semi-logarithmicdiagram shown in Fig. 6, respectively.In this study, five water samples were taken from dug wellsin the Neogene Hills. The measured pH values range be-tween 6.46 and 7.4 (neutral) and the conductivity valueswere between 587 and 2,260 lmhos/cm. These waters areclassified as ‘freshwater’ by the TDS system. The majoranion is Na, except at Poyraz Hill, and the major cation isHCO3, except at Poyraz and Orta Hills. The general watertype is Ca-HCO3 according to the IAH (1979). The averageMg/Ca ratio is 0.197 and Cl/HCO3 is about 0.606. In a Pipertriangular diagram, the water from dug wells plots on theCa-HCO3 area except for Poyraz Hills water. Due to theinfluence of seawater at Poyraz and Orta Hills, the watertype is Na-Cl. In the Schoeller diagram, these waters plot ata lower part of the diagram, but give similar signatureswith seawater. According to these results it is widely ac-cepted that freshwater can be supplied from the limestonelevels of the Neogene Hills according to the water qualitycriteria for dried marshes.

Tab

le6

Ch

emic

alco

mp

osi

tio

no

fw

ater

sfr

om

inan

dar

ou

nd

Izm

irB

ird

Par

adis

e.V

alu

esin

mg/

l;T

DS

tota

ld

isso

lved

soli

ds;

EC

elec

tric

alco

nd

uct

ivit

y(l

mh

os/

cm);

SWse

awat

er

Sam

ple

no

.T

DS

Dat

ep

HE

CN

a+K

+C

a2+

Mg2

+C

l–H

CO

3–

SO2

–4

CO

2–

3%

Na

Wat

erty

pe

IAH

(1979)

11,

377

24.4

.00

6.75

2,26

034

238

7326

515

283

100

–73

Na–

Cl-

HC

O3

274

124

.4.0

07.

321,

100

110

2110

010

160

250

90–

48C

a–N

a-C

l–H

CO

3

330

124

.4.0

07.

4042

012

1260

454

122

37–

20C

a-H

CO

3–

Cl

452

826

.5.0

06.

4658

720

111

27

3628

171

–13

Ca-

HC

O3–

SO4

588

126

.5.0

06.

531,

127

814

107

4378

366

202

–29

Ca–

Mg–

Na-

HC

O3–

SO4

622

,174

24.4

.00

7.82

36,1

005,

417

313

696

1,33

412

,300

249

1,75

511

063

Na–

Mg-

Cl

73,

865

14.1

0.00

7.60

3,55

01,

255

1161

541,

830

556

98–

88N

a-C

l8

2,72

124

.4.0

07.

204,

320

885

3641

451,

050

565

99–

87N

a-C

l–H

CO

3

94,

860

14.1

0.00

7.80

4,49

01,

656

1141

542,

420

591

87–

92N

a-C

l10

775

11.5

.00

8.72

719

105

1061

3150

300

200

1846

Na–

Ca–

Mg-

HC

O3–

SO4

1187

114

.10.

008.

893

010

723

5146

8532

521

717

45N

a–M

g–C

a-H

CO

3–

SO4

1261

320

.8.0

08.

1971

656

2464

3156

262

114

635

Ca–

Mg–

Na-

HC

O3–

SO4

1364

220

.8.0

07.

9667

846

2365

3561

299

106

730

Ca–

Mg–

Na-

HC

O3–

SO4

1461

320

.8.0

07.

8965

146

2459

3343

299

9910

31C

a–M

g–N

a-H

CO

3–

SO4

1560

620

.8.0

08.

0665

943

2360

3245

287

109

713

Ca–

Mg–

Na-

HC

O3–

SO4

1622

,023

24.4

.00

7.75

22,4

004,

600

208

810

1,20

58,

000

150

7,00

050

60N

a–M

g–C

l–SO

4

1788

,933

24.4

.00

7.44

12,9

400

18,4

501,

199

3,29

28,

230

56,8

0012

478

058

50N

a–M

g-C

l18

59,4

7914

.10.

008.

3017

,500

16,7

361,

086

710

3,39

031

,800

237

5,44

872

71N

a–M

g-C

l19

560

26.5

.00

7.32

565

4510

6523

3322

715

7–

30C

a–N

a–M

g-H

CO

3–

SO4

201,

616

26.5

.00

7.26

2,12

034

814

8055

430

398

279

1265

Na-

Cl–

HC

O3-S

O4

2156

226

.5.0

06.

7755

945

1056

3433

225

159

–28

Mg–

Ca–

Na-

HC

O3–

SO4

SW39

,763

8.01

61,8

0011

,955

936

532

1,05

221

,850

373,

401

–83

Na-

Cl

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Environmental Geology (2003) 43:825–835 831

The water samples were taken from saltpans in the rainyseason. Measured pH values are approximately 7.6(slightly alkaline) and conductivity values range between22,400 and 129,400 lmhos/cm. The water type is Na–Mg-Cl according to the IAH (1979) and these waters are‘saline’. water according to TDS values, and can reach88,933 mg/l.A high concentration of salts in the irrigation water ren-ders the soil saline. This affects the salt intake capacity ofthe plants through their roots (Srinivasa Rao and others1997). The Wilcox diagram (1955) is used for the classi-fication of irrigation water. This graph is based on theelectrical conductivity (EC) and on the sodium percentage(%Na). The marshes, Can Suyu Pond and the saltpans are‘unsuitable’; Gediz River and Neogene Hills waters are‘good to permissible–excellent to good’, except PoyrazHill, which is ‘doubtful to unsuitable’ (Fig. 7).

Open channel waters in andaround Izmir Bird Paradise

Water samples were taken from some open channels in therainy season because these channels transport Gediz Riverand irrigation waste waters to Izmir Bird Paradise. One ofthem was taken in front of the Visitor Centre and theothers were taken around Izmir Bird Paradise. MeasuredpH values ranged from 6.77 to 8.3 (neutral to slightlyalkaline) and the conductivity values were between 559and 17,500 lmhos/cm. The dominant cation was Na andthe dominant anion was Cl in front of the Visitor Centre at

Izmir Bird Paradise (18) and east of the Maltepe LeatherZone channel (20). At the other channels, Seyrek (19) andMaltepe (21), the water type is Ca–Na–Mg-HCO3–SO4.According to TDS values, 18 and 20 are ‘saline’, and 19 and21 are ‘fresh’ water. When an area of low rainfall and ac-cumulated solutes is reclaimed by irrigation, the increasedwater supply tends to leach away the solutes and sulphateappears in the drainage water or return flow (Hem 1989).Therefore, these waters, like the river waters, have sulphateconcentrations of more than 20% (meq/l).These waters, determined by the Piper triangular diagram,are shown in Fig. 5. According to this diagram, 18 and 20are a Na-Cl type; the other channel waters (19–21) are aCa-HCO3 type.As shown in the Schoeller semi-logarithmic diagram(Fig. 6b), seawater and open channel waters that wereclassified as 18–20 give similar signatures due to releasedwaste water, which consists of high levels of dissolvedsolids from leather and agricultural processes.In the Wilcox diagram, these waters are classified as‘unsuitable’ except for the Seyrek and Maltepe channels(Fig. 7).

Water pollution in and aroundIzmir Bird Paradise

The sources of the environmental problems and heavymetal analyses are given in this section. In MenemenPlain there are two hazardous factors for Izmir BirdParadise:

Fig. 5Distribution of waters in the Piper triangulardiagram

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832 Environmental Geology (2003) 43:825–835

1. Industrial zones: one is constructed in the delta of theGediz River, and is named Ataturk Organized IndustrialZone; the other one is the Maltepe Leather IndustrialZone. This latter zone is constructed on the Tasli Hills,which consists of Neogene sedimentary rocks in thenorthern part of Izmir Bird Paradise (Fig. 1). Both ofthem do have purification systems, however, especiallyin the Maltepe Leather Industrial Zone, great quantitiesof water are used during leather processing. This resultsin wastewater that contains organic matter such as bothsolid and liquid proteins, bristles, wool, leather parti-cles, magnesium, calcium and chrome. The mostimportant characteristic of this wastewater is its highsalinity and low alkalinity (Somay and Filiz 2001b).Waters that include heavy metals such as chrome arereleased into open channels that transport freshwater toIzmir Bird Paradise, after being used in the leatherprocessing (Somay and Filiz 2001b). Heavy metalanalysis was done from the open channel (21) thatcarries water to Izmir Bird Paradise from in front of the

Leather Industrial Zone (Table 7). According to thisresult Cr and Pb values significantly exceed the TSE 266and EPA 2000 standards (2000). Dead fish are seen inthis channel, probably due to the high level of Cr that isused in the leather processing.

2. Gediz River: this river is already contaminated by do-mestic, industrial and agricultural wastes from differentplaces, especially Manisa (Somay and Filiz 2001b).Thus, this water cannot be available for treatment of thereeds. Heavy metal analyses have been taken fromthe beginning of Lower Gediz Basin to Maltepe wherethe river spills out to sea and are shown in Table 8.

In the river, Fe, Pb and Sb values are above the standards.This will have a tremendous effect for Izmir Bird Paradisebecause the open channels to the marshes transports thisriver water.The heavy metal contents analysed were taken from openchannels in front of Izmir Bird Paradise (18), Can SuyuPond (9), Bedir Bridge (10) and the reed beds (7). Theresults of the analyses are shown in Table 9.According to these results, the water from the openchannels contains high levels of Pb, Cr, Cu, Sb, Fe, Mn, Niand Cd. Because this channel acts as a kind of wastewater

Fig. 6Distribution of waters in the Schoeller semi-logarithmic diagram. AFresh- and saltwater ecosystems, B open channels and Gediz River

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Environmental Geology (2003) 43:825–835 833

and irrigation return flow channel, there is heavy metalcontamination. The heavy metal content of Can Suyu Pondis composed of Pb, Cr, Sb, Fe, Mn, Ni, Zn and Cd. In themarshes, Pb, Cr, Sb, Fe, Ni, Zn and Cd values are highaccording to TSE 266 and EPA 2000 (2000) standards.

Without any doubt, these results show that Izmir BirdParadise is being threatened. This contamination isprobably a result of the industrial zones and agriculturalprocesses.

Conclusions and recommendations

Average yearly rainfall in Menemen Plain is estimated tobe about 546 mm whereas the mean actual potentialevapotranspiration is 894 mm, which is estimated as‘drought’ according to the Thorntwaite method (1948).The mean temperature is about 16.9 �C.The groundwater flow direction is from SW to NE, indi-cating seawater intrusion occurs around Izmir Bird Para-dise. It is seen that groundwater levels have decreased byabout 8–13 m in a 20-year period because of long-termdrought and excessive pumping of groundwater.There are two ecosystems coexisting, salt- and freshwater,within Izmir Bird Paradise according to hydrochemicaland hydrogeological data. The freshwater ecosystem con-stitutes the marshes, Can Suyu Pond and Gediz River. Themaximum value of conductivity is 36,100 lmhos/cm in themarshes, and the minimum value is 651 lmhos/cm inGediz River. In the marshes, Can Suyu Pond and BedirBridge the major cation is Na and the major anion is Cl. Inthe saltwater ecosystem, the EC values reach129,400 lmhos/cm and the water type is Na–Mg-Cl. Onthe Schoeller semi-logarithmic diagram, all the freshwaterecosystem waters give similar signatures with seawater.Therefore, seawater intrusion plays an essential role inboth fresh- and saltwater ecosystems. However, GedizRiver waters plot at lower levels in this diagram. Accordingto the Wilcox diagram, all these waters are ‘unsuitable’except for Gediz River.It is very difficult to avoid the conclusion that the marshesin Izmir Bird Paradise are drying out due to the work onthe Gediz River bed in 1893, the long-term drought and theseawater intrusion in Menemen Plain. Therefore, surfaceand groundwater inputs have declined. In this study, afreshwater resource was investigated and water sampleswere taken from dug wells in Neogene Hills. At the dugwells (in Poyraz, Orta, Lodos and Tasli Hills) EC valuesrange between 420 and 2,260 lmhos/cm. The dominantcation is Ca, the dominant anion is HCO3, and the averageMg/Ca ratio is 0.197 and Cl/HCO3 is about 0.606. Thesewaters are also suitable for irrigation. These analyses on

Fig. 7Wilcox diagram for irrigation classification of the waters

Table 7Heavy metal analysis of the open channel in front of the MaltepeLeather zone (values in mg/l). Bold data are values that exceed TSE266 and EPA 2000 (2000) standards

Location Cd Cu Cr Fe Mn Pb Zn

21 Trace Trace 0.419 0.245 0.024 0.050 0.032TSE 266 0.005 0.100 0.050 0.200 0.050 0.050 0.100EPA 2000 0.005 1.300 0.100 0.300 0.050 0.015 0.150

Table 8Heavy metal analyses of Gediz River (values in mg/l; TSE 266; Somay and Filiz 2001b). Bold data are values that exceed TSE 266 and EPA 2000(2000) standards

Location Cd Cu Cr Fe Mn Ni Pb Sb Zn

12 Trace Trace 0.031 0.540 0.025 0.014 0.040 0.215 0.08613 Trace Trace 0.017 0.461 0.051 0.014 0.052 0.328 0.00714 Trace Trace 0.017 0.324 0.001 0.017 0.055 0.370 0.02115 Trace Trace 0.024 0.508 0.001 0.011 0.052 0.265 TraceTSE 266 0.005 0.100 0.050 0.200 0.050 0.050 0.050 0.010 0.100EPA 2000 0.005 1.300 0.100 0.300 0.050 – 0.015 0.006 0.150

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834 Environmental Geology (2003) 43:825–835

water from the limestone that forms the Neogene sedi-mentary rocks suggests that this could be used as a newfreshwater source according to the hydrochemistry data.For, the water samples that were taken from open channelsin and around Izmir Bird Paradise, the conductivity valuesranged between 559 and 17,500 lmhos/cm. The channelwaters that are found in Izmir Bird Paradise and in Mal-tepe are classified as ‘unsuitable’ in the Wilcox Diagram. Inthese channels, the major cation is Na and the major anionis Cl because the waste waters consist of high levels ofdissolved solids released from leather and agriculturalsources. The other channels (19–21) are ‘excellent to good’on the Wilcox diagram.The heavy metal contents of the freshwater in Gediz Riverand some open channels exceed the TSE 266 and EPA 2000standards (2000). In the freshwater ecosystem this in-cludes, especially, Pb, Cr, Sb, Fe, Mn, Zn and Cd; in GedizRiver this includes Fe, Pb and Sb; in the open channel inIzmir Bird Paradise it includes Pb, Cr, Sb, Fe, Mn, Ni andCd; in the open channel in front of Maltepe Leather Zone itincludes Cr, Fe and Pb, which clearly exceed the tolerancelimits of TSE 266 and EPA 2000 standards (2000). Thepollution load recorded from Gediz River to the marshes isprincipally caused by discharge from the industrial zonesand by periodic pumping of groundwater in MenemenPlain. Also, the presence of towns and human activities,such as agriculture and urbanization result in pressure onthe quality of surface and groundwater in the study area.From the point of hydrogeological practice, it is importantto note that in the near future this pollution will threatenthis wetland ecosystems. Therefore, the following pointsneed to be addressed:

• Excessive pumping of groundwater must be preventedin the Menemen Plain.

• The waste and waste waters should not be released toGediz River basin.

• Industrial zones must use purification systems.• Farmers must use fertilizers and pesticides conscien-

tiously.

References

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Table 9Heavy metal analyses results in Izmir Bird Paradise (values in mg/l). Bold data are values that exceed TSE 266 and EPA 2000 (2000) standards

Location Cd Cu Cr Fe Mn Ni Pb Sb Zn

7 0.013 0.019 0.110 0.677 0.050 0.150 0.180 1.477 0.5529 0.015 0.021 0.110 1.555 0.400 0.201 0.160 1.705 0.471

10 0.004 0.004 0.120 0.677 0.088 0.116 0.080 0.682 0.04718 0.086 0.170 0.440 8.929 1.050 1.343 0.560 5.909 0.087TSE 266 0.005 0.100 0.050 0.200 0.050 0.050 0.050 0.010 0.100EPA 2000 0.005 1.300 0.100 0.300 0.050 – 0.015 0.006 0.150

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Environmental Geology (2003) 43:825–835 835