Ground Cover: Sanliurfa Province, Turkey

1990

Changing Agriculture: How the Ataturk Dam Impacted Sanliurfa’s Agricultural Production

Ground Cover: Sanliurfa Province, Turkey

1998

Change in Crop Yield By Province Cotton 1991-1998, Wheat 1991-1998

Background Methods Initial Observations

Comparative Analysis & Conclusions

TheAtaturkDamisthecenter-pieceoftheSoutheasternAnatoliaProject,amassivepublicworkspro-gramthatextendsacross9provincesandincludestheconstructionof22damsand19hydro-electricstationsontheTigrisandEuphratesRivers.1ThegovernmentoftheRepublicofTurkeyhasspent$32billiononthisproject,whichaimstoincreasedo-mesticenergyproduction,boostagri-culturalproductivity,andresolvetheeconomicimbalanceinthesoutheast-ernprovincesofTurkey. OncetheAtaturkDambeganop-eratingin1992,theman-made48.7km3reservoirprovidedasteady lowofwatertoirrigatehundredsofthou-sandsofhectaresofcroplandinneigh-boringprovinces,likeSanliurfa,viamassiveundergroundtunnels. Typically,irrigatedcropslikecot-tonaremorepro itableforsmallfarm-ers,manyofwhombeganreplacingtheirnon-irrigatedwheat ieldswithirrigatedcashcrops.Asaresult,theregionfacesanintensifyingriskoffoodinsecurity.2 Thisprojectusessatelliteimage-ryandTurkishAgriculturalCensusda-tatomeasuretheimpactthattheAtaturkDamhashadonagriculturalproductioninsoutheasternTurkey.UsingtheprovinceofSanliurfaasanexample,thesemapsdemonstratehowrapidlythelandscapehaschangedoverarelativelyshortperiodoftime.

ThesemapswereconstructedfromhighresolutionimagerytakenbytheUSGSLandsat7satellite.ImagesfromcomparabledatesinSeptember,whencottonisnearingharvestinTur-key,wereselectedwiththeGlobalVis-ualizationViewer.Theyears1990and1998representarelativelyshortpas-sageoftimebeforeandaftertheopen-ingoftheAtaturkDamandthesatel-litecapturedhigh-qualityphotographsinSeptemberoftheseyears.

Landsat7ThematicMappercap-turessevendistinctwavelengthsofvisibleandinfraredlightastheyre-lectofftheearth'ssurface.3Aftercompilingthedifferentbandsintoasinglerasterimage,twoadjacentras-tersfromeachtimeperiodwere'mosaicked'together.

Aftermaskingtheassembledras-terimagestotheborderoftheSan-liurfaprovince,itwasapparentthatseveralpixelsweremissingdata.Thisslightde iciencywasdisregardedduetothelimitedscopeoftheproject,andtheexcessiveresourcesthatwouldhavebeenrequiredtodownloadandmosaicthemissingsegmentoftheLandsatimagery.

Next,eachyear'sderivedrasterunderwentseveralexperimentalIso-ClustersandMaximumLikelihoodClassi ications.Aftermuchtrialanderror,therastersweredigitallyorga-nizedinto25classesaccordingtosim-ilaritiesacrossthesevenbandwidths.Theclassi icationsweremanuallycomparedwiththefalse-colorRGB

compositesforaccuracyandthenpainstakinglyreclassi iedinto ivegen-eralcategories:

WaterTheEuphratesRiver,irrigationchan-nels,reservoirs,etc.AgriculturalVegetationGreencropland,readytobeharvestedNon-VegetativeCroplandInactivefarmlandor ieldsgrowingnon-irrigatedcropsonadifferentcycleNon-ArableLandRock,mountain,pavement,buildings,towns,etc.SaltSaltaccumulatesasaresultoftheriver'snatural lood/droughtcycle. ThemapsinFigure1representastaticpictureofgroundcoverbeforeandafterthecompletionofthedam.Toobservechangeovertime,the1998mapwasreclassi iedagaintoaspeci icnumericalsystem.TheRasterCalcula-tormultipliedthenewmapwiththe1990mapandcreated25newclassi i-cations,showninthetabletotheright. The inalmap(Figure2)requiredanotherreclassi ication,groupingto-getherthepixelsthatdidn'tchangebe-tween1990and1998andgroupingtherestaccordingtotheir'changed'statusin1998.Becauseeachpixelmeasures30mx30m,calculatingthetotalareaofeach'class'simplyre-quiresmultiplyingthequantityofpix-elsby900andthendividingby1,000,000togetaresultinkm2.

Thisproject’sobjectivewasnotsimplytovisualizethechangingland-scape,butalsotoquantifytheimpact.Inthetableabove,theshadedboxesindicatelandthatwasleftunchangedbytheconstructionofthedam.There-mainingboxes,whichtotal6,996km2,revealhow36%ofSanliurfa’sland-scapechangedinjusteightyears.

Thetotalamountofagriculturalland(vegetativeandnon-vegetative)declinedby2,961km2,buttheboxeshighlightedinredshow1,210km2ofagriculturalvegetationwasadded.Asaresult,vegetativeagriculturallandmakesupamuchhigherproportionofthetotalagriculturallandin1998.

Inshort,lesstotallandisbeingcultivated,butinSeptember—whenir-rigatedcropslikecottonarereadyforharvest—moreofitisvegetative. 

ThisresultiscorroboratedbytheresultsofthecropyieldanalysisinFig-ures3and4,ontheleft.Figure3indi-catesthataveryclearincreaseincot-tonproductionoccurredinprovinceswheretheSoutheasternAnatoliaPro-jectimprovedirrigationfromtheTi-grisandEuphratesRivers.

Simultaneously,cottonproductiondecreasedinmostotherprovinces,sig-nifyingageographicshiftinthecoun-try'scottonproduction.

TheUSDAForeignAgricultural

Servicenotesthattheregionexperi-enceda50%increaseinlandusedforcottonproductionbetween1994and2001.Overthesametimeperiod,thesoutheastregionwentfromproducing25%ofthecountry'scottontoproduc-inghalfofthewholecountry'ssupply.6 

Withalargeruralpopulationthatreliesonsubsistencefarming,almosteveryTurkishprovincegrowswheat.Again,thesoutheasternprovincesout-strippedthegrowthoftherestofthecountry'swheatproduction,butnottothesameextentthatitdidwithcotton. 

Between1991and1998,sixprov-inces(allinthesoutheast)morethandoubledtheircottonproduction.Sir-nakproduced18timestheamountofcottonitproducedjustsevenyearsearlier!Meanwhile,Sanliurfawastheonlyprovincethatsawmorethana100%increaseinwheatproduction.

Whilethisstudycannotconcludethatfarmersreplacedtheirwheatieldswithcotton,thedatashowsthattheincreaseintheproductionofcash-cropsisoutpacingtheincreaseintheproductionoffood-crops.

ThemapinFigure2accentuatestheincreasingconcentrationofagri-culturallandinSanliurfaandsupportsthehypothesisthatlarger,commercial-scaleagricultureisreplacingafrag-mentedsubsistencefarmingsystem.

Itisdif iculttouseLandsatimagestopreciselydifferentiatebetweencrops,buttheTurkishAgriculturalCensusrecordsan-nualcropproductionandorganizesthedataintodifferentlevelsbeginningin1991.Fig-ures3and4demonstratethechangeoversevenyearsinnationalcropproductionac-cordingtoprovincewhereproductionismeasuredintons.

Wheatandcottonwerestudiedtoob-serveiffarmerswerereplacingstaplefood-cropswithcash-cropsinresponsetothein-creasingavailabilityofirrigation.Increasingcash-cropproductionchangestheeconomicandsocialclimatebyencouraginglargermonocultureoperationsandnon-subsistencefarmingpractices.

DatafromtheAgriculturalCensuswasreformattedandjoinedtothegeocodedvec-torshape iles.Percentagechangewascalcu-latedbytheformula:

ClasseswerethenselectedtobestdemonstratechangingtrendsandthecolorschemeimportedfromColorBrewerwasmodi iedtoemphasizethedifferencebe-tweenpositiveandnegativechange.Prov-incesthatdidnotgrowthespeci iedcropinbothyearswereclassi iedandcodedsepa-ratelyas"nodata."Majorriversandsigni i-cantcitieswereselectedfromlargerESRIdatasetstoprovidevisualcontext.

Asexplainedpreviously,anareaof~83km2ismissingfromthe inalmosaickedrasters.Asaresult,the inaldataforSanliurfaispartiallyincom-plete.

TheIsoClusterreclassi ication,thoughhighlyaccurateformostoftheprovince,misclassi iedasubstantialnumberofpixelsalongthenortheastborderoftheprovince.In1990and1998thenon-vegetativecroplandareaappearstobemountainousandrockyinthefalse-colorRGBphotos.Becauseitrepeatedtheerrorinbothmaps,thisshouldnothavegreatlyimpactedthedatainthecomparativeanalysis.

Theprocessofreclassifyingintothe ivegeneralcategorieswassome-whatsubjectivebecausethereclassi i-cationtheprocesswasdonemanually.Theclassi icationsystemalsofailedtodistinguishbetweenman-madeimper-viouscover(urbanization)and‘natural’non-arableland(rock).TheIsoClusterwouldlikelybeunabletodistinguishthedifferenceiftheman-madestructuresweremadeoutofma-terialcutfromthe‘natural’non-arableterrain.

Amoredetailedanalysisandlarg-er-scaleprojectwouldbene itfromacloserexaminationofothercropsandanexpansionofscaleintoneighboringprovinces.

Thesigni icantchangeingroundcoveroveraneight-yearspanisimme-diatelyevidentwhencomparingthemapsinFigure1.Theeyeinstantlyno-ticesthelossofbrown,non-vegetativecroplandandthematerializationofadistinctpatchofgreeninthesouthernportionoftheprovince.ThealmostrectangulargreenpatchistheHarranPlainanditistheprimaryareairrigat-edbythetwinSanliurfaTunnelsthatusegravity- lowtodeliverwaterfromLakeAtaturk.4Onlyoneofthetunnelshadopenedby1998,soitispossible

toimaginethattheareawouldcontainevenmoreagriculturalvegetationto-day. Theexpandingblueareainthenorthisalsoeasilydiscernible.TheEu-phratesRiver lowssouthwestalongthenorthernborderoftheprovinceandtheAtaturkDamislocatedjustbe-lowthepointwherethewaterbeginstoaccumulate.HalfofLakeAtaturkissituatedinSanliurfawhiletherestofthe817km2reservoirextendsnorth-wardintotheprovinceofAdiyaman.

Thesaltpatches,visibleinpinkinFigure1,aretheresultofthenatu-ralseasonal lood/droughtcycleoftheEuphrates.5Becausethedamreg-ulatesthe lowoftheriver,thebanksnolongerover lowandthesaltpatch-eshaveeitherbeen looded(inthenorth)orreplacedwithagriculturallandorimperviouscover(inthesouthwestcorneroftheprovince)asindicatedinthe1998mapandthechartbelow.

Limitations

Cartography, writing and analysis all executed by Eric Joseph Siegel according to requirements for ENV107. A special thanks to Instructor Carl Zimmerman and TA Carolyn Talmadge for their guidance and support.

Maps created on ArcMap10.1 with data courtesy of USGS Global Visualization Viewer (www.glovis.usgs.gov), Turkish Statistical Institute (www.turkstat.gov.tr), Global Administrative Areas (www.GADM.org), and ESRI. Projection: WGS 1984 UTM Zone 37S May 6, 2013

1. Republic of Turkey Ministry of Development Southeastern Anatolia Project Regional Development Administration. www.gap.gov.tr 2. Mustafa Yilmaz, “The Effects and Impacts of the Southeastern Anatolian Development Project.” State University of New York at Binghamton, (2012). 3. For more information see “FAQ about Landsat Missions,” www.landsat.usgs.gov/band_combination_browse_images.php 4. NASA Visible Earth: Ataturk Dam (2003). www.visibleearth.nasa.gov/view.php?id=3796 5. Dogan Altinbilek, “Development and Management of the Euphrates-Tigris Basin.” International Journal of Water Resources Development. vol. 20, no. 1 (2004). 6. FAS online, “Southeastern Anatolia Becomes a Major Cotton Producing Region for Turkey,” (2001). www.fas.usda.gov/pecad2/highlights/2001/08/turkey_gap/pictures/

turkey_gap.htm

(Production1998—Production1991)————————————————————————— x100 Production1991

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