THE GUARDIAN, 22 MAY, 2012

lHEGtlAADlAN, T~ May22,2012

XlVI

For The Record Irrigation development and practices:

The good, the bad and the ugly (4)

Prof. Jeremiah Diu dele Ojediran

Being text of an nauglni lecture series 7 de- evapommsutr;ltioo. the gjlts left behind In tM rate o( O~ meter per yur Ix~n 1965 and soli: ilncetne~mount la.Iten ur. byplanLund ~ 1981 (Bhumbla.1981~ In NigerLl. Nwa(1982)rrliwnld by 1'" ,1.• " ...Wi Oiudefe Oledlran 01 m01lftlolllw'vest isqulle~ JtlIiIC. pontd • rue In Woller table rrom 105m below soil ladoke Akinlob Ut1IY'ef"Siry ofTechnology, Og- The mOil! and the region. dle lirgt;rls thequoln- surface 10o-6Ocm ilnd .. oem wilhin 610 10 of IrrI~tion watl!'T .md consequemljl. the ~.lrsorlrrlga[ion In the Kad.tw.r: seo.orofthe tit)' bonlOSO reantt) IYno RlverPJotKLott<iir.m (l001) reportM SOIluaoolll!'d.~nd thesmalll!'T Is the qll.lmltyor lnllOt ""I the design ;tOO construction COM pmm-omeltT(l'IiIlc I) TodOlilS 6U-degm ~

(OjftIir.m.I991.J.~ n,tpt:nttrom('terme~ures

aust~ngll bI" wl'enO-SONOIndd~o­ ISOmm with the I Id of ~ force tran.$tlUtef .utdan optlc.ll SWItch rn JHttw:i)t Output sIgnals from the mruduar.n d 'VOUli swilChOlrl!' n!CCIfded In a dau ~r'ia i (unn«tlon block Tbt pcnttronel:1 r\G5 found 10 Ix pomble (about 34Cm I Jn~ "6Imp~ to oprr.ltt'. facllililtl!$ rq)liGat:iomo,. Ingltcrusts;lmple. mcdSUrn

force .Inti depth II' nlu/mum of SON ;Uld ISOmm rnpKti\""f:lvaud ~ix.M: ..UIu5 large qOlllgeap.Kityln a aat I kJ ;gt:r The Q[l\(,U(( ry Il!lformance ot the COM pm~rtNTm:"wa' I.st cll,tlned in. study I conductrd

on thcefffCts.,f r. ir,f.l1lmensi[l~ and dulOltiollS onCI'\W stnn,¢l?f .. sandy Io.Im S(liI(OjfdIl;u\' 1992b~ lhestl1dy w,lSCdmtd OUt undrors.mu· tnt'tl r;JlnfOiIlI,te l5itles of IS, 30 ;md SO mm/hourforltur ucmso(s,15.10alld 60 mInutes. The sixty dq m! (600) COM penetrometer wuustd In m!as' tnngcrusc Sl.nnglhal depth D. l.5mm,D 10.Smm lair l) Thrdau otMillOI!' $Ilawrd that the 'Oil crUs:! strength I~I with rainfall duroltions (orn .. trmitlesoft5 .• ud Kmmfhour. whlk-;n iI hlg1m' Intensit)'ofSOmnl/hour there Willi a noticeJble reduction In nul strength tnlhl!'cou~oflhf: )OmlnsOind 6l1mi'ls trulml!'fl[S. willi attl!'ndanl surfacr flooding..

1hI!' srudysugC':'!'.eU ~I fOfp~efgl!'nCt' lnigilltlon on thl!' '.lmty-loam soli. low Interuilin with shortdtuatk ru should be apphl!'d which willenb.ance InftliratlOn olnd .wedlingelTM!fgence, ".,itlle I'f'du II'S runoff and erosion.

Watl!'T loggm& mel $illinlutlon Watwoggilllalllisaliniudon of soils ,II"!!' physl· cal probIemslUOllOited Wlthsurf.Ke IrrilPtion.

Wuerlou;fng ~llu pnnwily from (JY('r.jrrig;ation, huaiqu;nedn'llagund~page from anills ;iIIld rulLhe<o VIOIterlogglngconcentntes wlts.dnwn ur fl'(. m IowI!'r partofthesoil profile. in the pl.Jnts' hJOljnl1 zone. Alblluuon. Ihe bulld-tlpof sodlur I n soils. Is a pan!cululydeU'i' mental form 0' saJ'nlutKm which Is dillIcuil to r«tlfydue 10 hsd< Sl rucuweffKt on struc-

II

no ...

IOn

IrrigatiofHnduceI ' SlhmtYQllolnse <lS 01 rt:Sull of lhf: Indlscrimhu.u uw: ofll'TigJUon Wilter, IITigr lion of saJlnf' soHs. ill1d r1s1ngll!'Yl!'lsof wlilll!' groundwalffcom!lined with Inadequate It.lcbfng..Whmsurt.a ..... terorgroundwillrrcontoJinIns mineraI ulu b u;rd forlrr1gatiog crop5,wlu .tr~C.oln1f!d InO' m. rool .zonc..ln!.he procnsof

Consequenl ,., Ihe high seepage rales reported contlibutions to the groundwater table in rrigated areas have been stlbslan~ally Ihrough seepage losses from ca""ls and aggravaled by poor or sometimes lack of proper

drainage leading to rise in water table.

In recent times. the rate of rise in waler lable has hecome a global concern, having reached an alarming level in some iniga~on projecls.

nlnfa),'wl \s ..... II~blI!' to lucholl\v.1yrheollCCUmulatingwhs.

Excess gil wilhln the rOOf.zone Rduces planl growth due to Increased energyth.u th~ plolm must t'Xpt'nd toacquin! Willer-from U,e soil Thus olIcute soli dl!'gritdalioo ~Iu from wlinltYolnd consequently Willer logging. lbese physical problvns whICh nnollltlte on 1mgiliion schmIesafttrthecomrXellon of Infrastructunl constructions an! Of grt',t! concern olnd olin! tenTltd "bad-. as they ollIl!'<t the ~11 pcrfonnanu of the scheme 0100 JOfTIetlmes ~ suit in permilnmt damagl!'S. Thesor problems In elude Wilter loggl ns. Q,lInhy. rise In ground water [;1hle. seepage from can.tis.efOSlon and flood haurds.seepage. rise In Willer rnble. watl!'f" Ioggiog .00 glinlry art'dO$l!'tym<nl!'d with the 10creaSotd inddence of one leolding to the olggr;tYalian of the other.

It is generally bl!'lieved olnd ~I $ludiC':'! h.Ivr conflnncd that ~ high pe:n:enlolge of water enlerIng InigOilion CollltllS is lost to seepdge before Il'achlng:the Odd. Figurn bl!"tVoftn 4().60S hillIt bet!n widely R:pOnro while dontd ~ 0(» SO'll: tw.oI!' ~rlO been reponed. In Nlgena.14'0Ye'T.11 Irrlgatiof'l efficlmcy was rt'pon:i'd forKildolw..

SKtOf or Kilno River ProjKt(O!.u. 1<l91~ while Maury-a and Ibralum (1'J93)corroborated bysUtIng thiU im~tIoo protects In NIgt'ria suffer From low WOller uriliZallon effickncy wflh est:lmalC!5 of bel:Wft:n lS-l5S.tnd So.6OJoYI!'nll Irri,oltlon elf.. dency fOf" surfaa ilnd sprinkler IITIgauon S)'5tl!'ms mpKIM!ly., Consequml on 1M high ~gr folIes I"q)Ortl!'d contributions 10 the groundwaU'r uble In 1m pted ol~ haw: bH-n sutKwltiallv through seepage lonesfrom canalsolnd olggravatrd by poor Of sommmes I.Jck of pfOpI!'f"dninagt' 1eMl109 to rise inWoliter table.

In reant tlmes.therate of rise: In""al~rtOibie Ius bKolTII!' olI Jdob,1I conam.lwving rt'a<:hl!'d an alilnnlog ~ In some Irrig;mon projKlS.ln India. WOItert.lble In Bhaman.al uochmml an!ol was reportl!'d 10 hdYe nst:n ,11 .In OIi,lnnlng

NISUCO scheme due lO walef logging. The olIbow

10Sst:S of ilgrkulturallyoo«pn:KlUct1vr: l.tnds

due todl!'terlontlon Of soil qUillitYolireol negadon or theeffortsgurt'd loWmJs roodSKUr1t)' .00 rood and Obre production worldwldl!.

Olemk,ti proble:ms(wlinlt)') On~ m.ajor lhrt'olt to the permant'nce of Im.Iso lhilt withm IS yelr5 of IrrigalkKl on the burn PolderProjKt. dlt' walerlolbll!' hold risen gilU'd ~grlcullure World-wide is U,e deletiongent'rallylownhln]O -6Ocrn bdowsoil ,uMe tlonof soil andW<1t6qualityOO Impdon rrom Prl'-pfOjKt 1~1s of 10 -147Cm. schemes. nlt' ions I"8ponslble rOf this dt'tl!rlOf'ilThe const:qumcesofhlgh~ ~nd rise In Ikm In qUolllt)'lncJlJIk Na+, K+.c.u .., grouOOWollIft"[;1bleolll' Willer I~ng iilnd IllMg;z+~ndCl-.As the Nol+(sodlum) prMominol(1!'S. creased soil SoIl1nl~ Wolter-ioggmggeneraJly de- soils an bKotm sadie. Sallnit)' is aggm"iIlM by ve~duetoOOl!'on combinatlon of the KCUmulillton of SOffieSoilu In bolh soil and groundwatl!1"_ Thestalus of sud! chmucal facfollowmg facton: o obslruction oflhf: n.nunl Oowof run-off. lors olIS. pH.Sodlum(Na"~ (akium (Gal+ )",nd Ma.gneilum (MgJ.+)lon coocenlrations.)OInd • crt'atlon of a liok bt'lWt'm surfacl! and grOUndWiiltl!f". mostly by ~ge and high Elaincal Conductivity (Ece)detefmlnes (hi!' watel IOIble: salinity level ortllt'sollolnd Wolter rt'gImes. n,e • lacko! orpoordralnagl!. ronantr.ltlOnofSodium.C.tlctum olIOO MagneThesecood £actor has 6n-n ll'pOrted IOCOnsU- sium lonure used for the COmCdtion or tute iI dangl!'T resulti III In ~ waU'f Jogging Sodium Adsorption R.ll10 (SAR olnd conSt"qUl'ntly t.ht' IntroductkKl of dlssotvrd SoII5 of v<lrtous schemes have obsel"'o'fillO Sillllnto Ihe crop root lone. lllt'seIWO raCtors be ImpOlctM bylhe introduction 0( irrigation, ~vtrtlUollybecome serious mm.tCe 00 lnidue lolncreasc In lhf:lrwlinlt)'SIolIus. Which 15 gaLl!'d fltlds olS st:W:riIl h«t.ilrnoflands are been the wllY'queOCl!'oflncn:.ue inOn!!' or a combiabilndoned due to tht' low productivity or Judi ~tIon of the abow ItsrM wlu. landslmme(hatdy~1inlryand Willl'"rT?8$mg AboutltO] millIOn hKl<lmare going out o! ~ In. ~(t9'J4)n!~rtl!'d that worldWIde production WOfldwtdl!'t'ach yNrdUl!' tOSOl~Imty olboul halror ~ously productM' imgatfd problems. on Impled lands.sahmzallon IS 1M lands hil~ been affected bywilter Ioggingand rTIollorGluse oflould Ixlng lost 10 production hotve bern ~bmdonotd. olnd is oneortM most prolifIC adverscmYironmenlOlllmparuolSSOdolttd with lnigatJon. SpKiOcally.in Indlil, 2.189.400 I~ oflmgalM l..nd holvebft:n olff«t.HI byWiltl!'T to,OOng. while In qUolintityi.ug thceconomlc ImpOlCloflniga].469.100hol has been affl!'Ctl!'d~wTlnlt)'(l}'".tgi. lion Induced ~hnlsallon. measurements holve t'J96:Slngh.loos~StocldellOIl In a review esti- genel'illlytxen limited 10tM OImounla( IoindOlrmatM INI roughlyone-t.h rd the imgaled fecttd or ilbOindont'd.EstJmatesofthe "rea afI.md In ma~rlrrlgatlon countries Is already af- fected holY!! ranged from 10 t048"'11:ofworldwkl.e rKU'd bySollinit)'with ilbout OS In IsraI!'I.loJ In UM.olIllrrig.ued olreL The arid and semhilnd ilreolS AustraHa.ISl:in Chma,50Xln Iraq .00 10l In hilY!! bl!'en «,ported to havI!' t'Xlenslvesallnlt)' Egypt.. tn Nlgeria. Mudi.m ,,00 Moholmmed probIems(FNllOO7 In oln ilnalysls of quest10nlt.1i1"8 (rom thirty (30) (1987)reponed f!']Ilcrutve water logging In Ihe ic.1dawaSKIoroflM Kilno RlYn"f'TotKI. while counlril!'!ion ellvtronmenlilllmpKUoflrrfgr KoIOl'NOle(1993)est.ImOlLl!'d wtaboulSOSofthe lion, tM poliulionoC surface olInd ground w~ter5 surfacr Irrlgattlon ilr!:01 of the Balwlorilrrlgalion wen perceived as • moljorconcl!m In roughly I projKt In SOkoto nate Is ollrudvWiltt'rlogg!!d.. InS I"!!'pllC!5(Bubbl!nJ9"~olnd $oUwllnltyWilli otedlran (1997)01150 noted the ahilndonmenl o( dnctibotd as • real holurdon Irrigation seMmes.. once prodUCIiYl! olI~ on l1'I'P(Ag.II~ Ilolkin Worldwlde.o\"I!'r lOSoflrr1g.ttKi lolnds have RIa: Scheme(lRJ')oJ'Qs[uJrOshun Rtvrr Basin been damaged by this menace.withdlsmbullon (Fig..Il)olnd on the Surface IrrigatKi olIll'as of the asshown In Table s.. TheChrutiiln illilyMonilOf

~XV~IL_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _llIE~-"GUARD= 1AN,1~~M,y22,!z0I2

200) estimated th,n ~.rly 1.6 miUkHl h~.u

16,000 lcm2/yedf) Is IosIglciballydul!! losalln-

1In AuslraJl. salinity 15 <1fNjor conam UUOIL

ilS II hils been observed to Ix' nVJging ilgricullunl ~nds. Bruer, (2002) iu ~pon by;ll commln~ on environment comprising of OYU 100 sctmlists, glMflUnWt ..gende: i1nd pnv,ul! §KIM groups.sut~ thaI Soiliniryis InONSin,in!.he

Murny.[H:riingbasin. which provides 4~Or

AustralJa'$~rultul1ll villu!! i.1nd and thallI (~muy)posed a rukIOS7,OOO k:rnl ofLlIld In

2001, md 15 txPKted to impaa no,ooo km2 by 2OS0 Also In Southwesuem Aunnll.l, ••00 bn2. of l.lnd onu used .s cropland or ~fUre,

w

Me now .u:h..affetted In PerosomI! 300.000 hila' Ihn050.000 hot of Img<1ble land suffen: (rom Ihis problem.

In the Umted St,ues(US)o1bour 15\01 lIngatN

land 5uifrr from some degrre of s.thnlLllfon or Willi!r logging ,whUe Solll iCcumuloillon is ~ pon~ loDe lOweringCTOp)wklson 25-30" (50,000 iJn2)~ US Imgaltd land{San00,1992}-

In Chillol, 20).01 IrriPled I.:md art repontd 10 brsutreung fromSdlmluuofl .lOd Ifus h.1SCUI Yleld~on nearly25:=ofChln .. ') Impled uoo ,~.1In "'hilt The combm~non ofW~ttr 108gmB clnd sahmty has also mllxed producu'ilt), on 1St 01 Chm~'s lITlgatf'd land{BruCf', 2007).

In P-;Igtna, [he saliml)'SIOItus of some Irrip non seMmtS louted fn theold sill Nonhrm SI~16 rr.'t'.. led thl-~bstlKe of salmlryulllerin 1962 ~Ild 1973. Howt\"tt, Maury", (1982) 0100 OIu (199I)obsel'V'td Ilwl salil\llyof v~rY1n8stvffil)'

..

:-oC"."

:';I~f

m w:r~ of th05CU-t:cm~ pm1OU~'

known to br free of w.linll)l.

111U.·.i1LU1hull uftlic Jn~"lul~dr~'\.b uf wllll1t}',lhO! uhnny ruM of (be sod and wattr rrglma on tl1lft irrigJtion schemes(ZPPP, Slmm'Mbbl, NISUCO. 8a0l~ aud IRP, Itollon) 10 Nlgt!n.I _rt SI udli~d. OjedJnn~1004). OcIUi obI~inrd lrom t~ stu(heJ Il)(huue genenUy )ow salinity Ie\.~l SpKlfiuJ/y. soils Withm tM top lOcm In the ZJ>t>p~,r.. whKh we~ Sdllor (mean pH "'4.6; Eel' =.\lOX UHmmholcm.uld ~ =O.-fOMeqlloog)dl'l'ICtpt1on now lends 16WOI,d) alkaline srams (mun pH =6.4;Ece""lS ,10. lmmholOfl cln..! ~ "" 0.lTh 1eq[100g) whilt lh~ 'oI.ruundwaleflVllhm Ihe lop]O ~6OCm be; low \011 surfact ~ 0100 10\VclrdS OIlkilint wllh pH r~ngt of 6.)-7.0; Kw= o.OO-fO.01')mmho/cm and ~from 1.l2-l.J7..... IIRP. Ih~ mullS iooicattttwt INo wxl Olme projeCt dR f\Of'1'NIl With low wit concentration {Tablt 6}Al NISUCO. Barila IMTno!an pH, ECr .. nd SAA values in 1987lndicatt' tlwl sa.oflht' so~1 stnes wt'R Ifllhr sahn~ filngt (0ru.1981) but twd shown sigruticam pH lncruse in all SomeS by 1995(0Jt!dInnJ997)annbuGlbltlotht I~ dtstNCtM flooding of tM sc~ Vlcr Chanctllor, sir, dlSttngwsbed l.K11H and gt'nlJeffiC.'n. in the wakt ~oo rulizalkm of thest' mtn.K"r the world over, studies and revil"WSof tnvuonmcnGlI implications of irrigation pr..c· tiCa begiln to nwke calls for~nVlmnmenl'al I'"' paCt messmenr (EIA) for ~ scht>me:!;. enVironmm~1 aoomng of aisting 5Chrmts aoo ~uent tnvlronmmw survilililnu of major W:iorsf paramelel'S on irrigation scilCmes. "lht:rrJOlY,ontnvlronmmGl.! 1mpaa ollrrigalion on soils. we devcloptd a compuler pmSfolm d6igned for GlPk1aunsmento(lm~ of irrigadOO practia on Sodium, Gtloum and Magnesium IOn concenualions, pH. EiKtTial CoOOOCtJllity(ECi!} and Sodium Adsorption R.J11O (W) of schemt soils (Ojf'diran, 1997: rn..->dlr3Jl Jod Sangoooym,l000b).

The program Is .IDle 10 outpUt ba.si!line dOli.. for first time~menL Whilt for monitoring. surveillance or audilinJr: the program, as.sesst:S the difTere:Jla 'Ilerween tht prtYIous .100 currenlsrarusof each soil (aoor estiIbllshes the significancr ollhe dlfft'~ocr at 'illevel updJtes tbe SliUUS or these (aaon for IhI! pur· pose offutUft' monitonngand pndkU possible futuR dftclS through SlmuU-lion UJing pro}ected values of racton. lht'computcrprogram w.sVillid.Jtrd using fI~1d ~u from impact ~t/ audltill3 studlH of Ih~ irrigation schemes In NlgffIa. TIlt' schemes ~ OSun-Oshun RlWr &asln Deve1opm~nt Authonty(OORBDII) Ricr Scheme, Itoi!un, Zauro PoIde:r Pilot Projt'a (ZPPP) B1rnlnKdlbi ~oo NlgerU SugMCOmpany(NlsUco) Irrig,ltkJn scbemt BKit;1.

ImpKU of lnigadon· llU UGLY Mr. lliaChancellor,slr,1 wish to \l!ltBale that everyaspeo of anydevelopm~nt In wh.altver fonn ~nd In whateYer sphtnofhle, must bt' prosecuted with a vi~ 10 improving the kxJ of huma.ntty. However. ~r this obJectMe Is negated,orlhcdT«t{s)oIanycomponenl bedarimenU1l to the ~t popu1.Jtion. esprd.l ly 10 thtlrwdlbe:lng ilrid health,such

oomo('/

Several instances in the recent past have shown that substantial economic losses have rt ulted from low health status offanners, inigators and other agricultural workers on inigation schemes, For iJlslance, Shanna, (1987) reported that in parts of Nepal, India and Afghanistan certain lands could not be developed in part due to malaria, but once the disease was brought under control there was phenomenal groJth in ~ttlement and agricultural production. The debilitating effect of this disease was observed amongst cbtt~n growers in the Gezira, Sudan inl974 when over 20%of the nonnal labour force was down with malana /md soldiers and students had to be brought in to save the crops. Similarly, on Sura inigation scheme in Kenva, + 1 .a deaths amongst children were one of the main reasons why many first settlers abandoned the scheme.

pPOp)e~nnuallyin-

asprctJcompoJlPntolthedeveiopmenl,can. wilhoul mlOcing_wonb bt' describro cI$ UGLY and concentd effom muu bt made lotlthtr reYerw thrmnd. pTt'Yl'nt funherefJeat.,orm theleaSI mlmmistsuch ta~ lolfheron, m thiS l«lllrr,1 twt POSlfed Itwt If· Tl3auon deo.--elopment 01100 proktkes Is nonctplion 101M rathugrMl'oi' rule of ~'eJ)1hmgand everyone Iwvtng.lh~ good,lhe bad ..oo lfit- uglyaspt'(ts..l hOld ~Iso mentioned incre~ lood ,lind fibrrproduct:ion. food srrunlY tlC.~S pasinV!' etrt'CtiOrlmgalion dew!opmtnt ~nd prama which shoukl mosl.ut 10 ImjXO\'N health of tbe farnen.nd othel operalonoftM schtonlt'_ HOWfYi!r.dlametrlo ullyoppome elTeruon d\t' htalth or farmers and" OIh~roperOilors 01 ImgauonschemH Iwvr btoen obSi!M!d ilnd Eed.c.mer tl.L (1990);NEST,~1991);ntrrn. 1991).lenstn.(1991) cllK! olot"llt,llOOlj h.. \~ "'~ tlk' pin.... lenct of ctfUln disuses on dim siles.OO ifTlo ~ooo sdtemt'Sd{ varying ~ Mound Smgh.(I99I~.l5 ni,il.ri!m n~ 9,c~ttgonsed cU blologll::al prob~ms.,somt'advt'ne e.trectS whICh emanatt an~rtlltcompleLionof mfnstructural CO'iStruCUOflS and when Imp lion scht'mes h.:iveCOIllt InlO operauon 10 IIIciude,hum;m h<'olllh, pestund dlstasts,olnd werd mlrsuuon.Tht5ethlftappearinterrp. wted as tht Ill(re.ue monrilqr.wclltS tht mho!!'. Thr Rresenaofrt)Crwlnol'l.1rge sur· lace ....us 0( ~mpoUII[IN \Y~ler And open watC'rsurf;lo(t'S aU Q\CI thf' fldd ,whleli chen (halXlrnze Irrtga'lQn de-wlupm<,nfS~" Jenlly hal t ImpoKt on tNo mKTO<hmat~ Of ,iloo .. ~a. Ottdu<ln,(!OOl) rxxrd (onUSli!m high ReUllve HumldJry(RH)dunng crsnvlulellry penodspuono Imgauon dtYelopmemon IWO u-helJW!S studied 1fl Niger... ThiS high RH provldrC(lndllclytenVlronmellll~tsilnd

tenruoflhtnumberol fect'td, ,lIld who5e quaUl)'oflifeand working capaClt :.;ue m.luud.and in ttrmJof dtdlh f..lf' from il Work~lde. somi! 2 blllkm people h'o't' Inare.uwhercl~\ are .. 1 nu:ofconirolC1lOg mawnoi. n,e 101.011 nllmber of peopk mffflrQ With rn.li.n.l IHsllmaTrd at 100 .0200 million wllh brl~n I clnd 2 million de~ths JX'r ~'C'ar. wllh illmost 901 oj .he nses InAiric~ ~erililosianct's In the rKtnl poul haVf'shown Ihal sul>!.I.nt~1 «onomic Josws ha...... Jt')ulled from 10,," hulth Slnusof farmers, tmgillon .oJ oct,t'r .gncullurcll WOlurson lmgiluon Khellk .. for InStance. Stul'TJW..(1917) 11'porttd lhal m ,Wonsof Nt'pal.lnlhil dod Afghamnan (tonam Iilnds could not bt de\1!lopl"J In piUl due 10 malan.a.. but once Ihe disuse was broughl undercontroitheRw.u pMnomtnal ~h In'itl1lemrm clnd OIlU1cultural pnxtuc. liOn. The lkbtllldUOg efif(! of Ihl\JI.seaSl! was oh",,,,'t'fi o1m,mf Q muOll ~ 10 f hI' GeZlfiil. Sudan Inl9!-l " 'hrn ovrr l()';OI.he no, mal LJbourlOl'Ct' wclsdown Wllh maldria and soldlen~nd sludents had to be brought m 10 sa\'r Ihe~, Similarly. on Bun Img.lIion schtmtln Kenya. maLina dr.. ths.amongst chlldren w.:Rone oIll\.! main 11'<I.5On5 why man) 11m settlt'rs .lYndoned th~ schemt DruguCdLl1W:m hasbecormodnhcult rectntly b«aUk>IM p.1rastte hOI~ become .t'SI~lam 10 cenamdrugsthcll ha\'ebtrn ~foro1long tlml' In rn..an), p.m!! of .h~ \~OI kI Imenupuon 01 dlst..S<t IfanmllSSlon ,hemlc,lJs forlhtcontrol of 1M ~~'hx.• he ~UIW. h,;~ b.:comc I~HlkcnY'C' btc"l1~ \Omt mosqullo\"ec!or )p«ItS hOI\e btc'ome rC<OtSl.m IOPrP\II)USI\' el Iffl1\r 'nSduLldt'§ilnd wmt 1IlS«IICld<!S Iw~ been b.1nned 10rrnVlronmentaJ Il'awm (fAD.

ht.llih. SUKt thlstleal wllh d~ wdlbtmg 01

matN ~oo mllhon people olJr IIlfeaf'd loOO the trclnSmlil'Ionoccurs m some14 cOllnmes(FAO. !OO7} The IIIfecuon IS pdnlculariycommon In children who play III Wilt~rmh.abllro bylht snail mLt'rmmiatt hoSL Exposure to Woiterbomedlstasts around Kampr (oml)dOIm In Kogi St.. te Nlgtna.Ara~ (1002).

SeveR mffoakln In chlklhood. IeKlsto Ion8' lerm d.molge 10 bladder. kidneys ilfId liver, which mI.)'UUst wlh manyye.n ilfterlht' oriJdn~llnferIlon_lnfeclloli at any age may ma1.eOHlplefeellln_lIandreduceworldng

~~I~I:h~;e:U~~~'::I~h:tlf!t ~r~~~~on-

Iht ImmNI,ne bt'ndicldntSof Ihe de\."tlop-

menl ilnd those of.he nurby residents.

-f.),1 Waler-bome and \'rilttr-rew.ed DlliUses

nl~wat'b"telaled disuses p~lentln 1m-

g.rtd ..reu, In oroerol slgiillic~ll(t,.1R classlfied ilS wa,et basai; YKIOl"WUtr-bomt, waler-bomr ~nd WilteroWnhtd. (Olu.I99I)and tbest IlXlud~maLuia. bllh.IrZ1Ol(Schlstosomi... sis). no.'t'f blindness( OnchocertiilSis). yrllow fever and br.aln fever. These have been Singled OUI .sof p.lnJcular Importance beca.Ust thry either ulistdeathandf~Rdbablhl)'or

.. urge proponlOn of thr popui.1tiOn at !'Uk becomes W. or

tht')' art' pa.rticularly difficult to control onu rttey b«OmrwidrspTead orwhen theyue r~ denuc.or the mulunglll-hC'ahh lamalongtlmt.

(Tiffen.I99I)._ Olherlmgatioo-Rlated hcallh nsb include [host' oISSOCIilti!d With Increol.std use of agrocht'mk:a.1s, deteriOGltkln of ~er qualJty. and increil.Std populanon ~ in thraru. Th~ Ruse of wmewarer for lnigalioo has lilt pottnll.l,dependingon the utent oflreatm~nl, ofl.clnsmlttingCtlmmunlcabledlseases.. The popuutlon groups., riskJndude ilgricultural worktrs, consumers of Cf!lPS ~nd mt'at from lhe W4l$It'WiIlU'lrrigiUcd Rekls,.nd peopl~ It¥1"1 ntoillb)tSp~r irn.g.Iuon poses.m~ddj.. tiona! rult through tht poIrntial dispe:rsai of pathogens Ihroogh Ihr ,\ir.

The rlSktiw ORe or maRof walx:lvedls.o;\Sts Is introduced or has an Incrusrd Impact Is most likely In Irrigation schell\H wheR (FAG,

'OO7't

Soli dn{rus,r is poor,dralll~.Fc.m.J.1s ~re either dme:nl., Di<U)' designf'd a.ndJOr m;.1Illilined; rice orsugarcane lscult!v;J.lm; night SlOr.gt reservoln an consuua-td; bolTOW pllS o1~ left with ~[Willefj cana.lsa.re unlined and haytuncheck£d vrgel~ tlon growth.

Malana Mal.;uia. is byfilrtht ll\OU Important oflhe distasrsOCCUrringon irrigalion schemes. boch In

!007~

BJl~rz'iI

~~~~~~!~.t:m~rtk.~~~::I~;a.

IhtreareSl'fl~i Iubl~he ltbeo~ ,G,.,f~ma ~nd.

worv ilnd .. 'ieCjuenct"lln manycase o..>adUIlloI (198'7) ~ponl"O 1.1 5~-; Incn~R In prevall'flct kYoel of tchlJi piC'''~ In Malum-filShlaherlMCOnstr\l::l on .. s lleanh dams rnr.nt speclhead\' for 1m Ion. OnI(I!;90~ .also rtpundl inc usesm pre-proIff' li!'I~1 01 schluosoml.!5iS <f'd maliln.l from ~ O.... lh~ Ihan IO~ ro]u\ IflI.i 10\ ~t\'alfn(l! II.'Ye1s r~p«u.-cly one and )UI, rea!S afu!q.h~ (onnnJtl,lOl'l 01 me ..... mlld..trll_r .. o).:un. '(l9I7) repon~ Inctdrncl'1 ot s hlllD5Ol1llo1S1S Ifl the ayan Rl\'Pr~m prtlfK1.. *h If'(06Duit', 2001) RPOnN IhiU IhrConm Ufll~ Itl Oyan dam, Ogun ~1"lt, Wltnrss«! ill ou~,~tOT u,rin.ry sduslosomlaSI~ m19b3, OUi ar after IISCOnstnKt.on, Wlth.n ,*PId Ipi illtllaof aver '1010 .nd high rain in .lll ,gt ~y(lIlPS was r...corded. ln th~ NOllheQl Sidle 01 Kano. there IlolS bM1 WKii5Fn idlir1ri1!plflC'nI of COinlkunu. Many of 11K I w"Ii!T b9dltS have bf.o,m lound locontam P' Qr:~lol snaillOli~nntJi.. te h<b15 (8et:u.'rton ttll.. 1:Ji'i).lYblU{l007) 11'poned the presenceo ~ltJbosus and ~ peeffi!lri In/auroid.im(J(.;I1li Slaqe} I Gklb.h~ anl!Slilllolrrd l' 10 l"1illu)A people ~11' Infecttd by Ihlliduup.. nd lfiIoscnlSSlon IXLl1r'S In 74 cou mnr<;(Ttft 'n. 1 1~'~ Ibt'ellt("1 oIlhlsdiseaseon ~t'obdart1fib11' prodlJ~llOn tffons 00 sc \tnlh IS tnonnoU1ln -.a ml'(oon.asrudyof lflld ,rid prodt.Jcuvlry 01 nct!!rowl"n. ihO\lll'd I ldt ~ IO~ Itducupn m Ih~ In,;Klrnctof unnal) Sth!$tQS(lmu.sb~s .KeOfllp.1Altd byil-f. 'n, ro ... III ,nxttkllon. o,edu,Ifl..lOO-fbl III oio.l~~of II~ ffl.orUsof dnnual r~ponrd Ust~ II Ihl~ sc~emH in 'Ilg~r'ol®sef\..-d llul H USI~ (e.. tulrd prom'JlPnlly~1 NblXO ...nh.m ."nual a\-tra~ ,)1100 rtponed c.bts ~"!.e~~ ~t~t~~ilnE'P"no ,K"lrom Ihtl.cf·

,00

~ilons

SobslJmlJI tn ml RStwthWHf'gt'aRd tow.uds~n~lJl)fImenlallml"ct USdSmtnt of Imga 'lOfI EtTrnsof Irri),lIjoln p;,Kl IceS; on human h~~hh III NlgrJilwt teOOell.etptiOll tOtl'<ilnn, 1991;Oi~(lIrai anJ Sangod~m. lOOO;O)f'dlran.1004), f nvtl'OnmrntallmpacU ollmg.ulon schelTlH In Iht .!tsub-Kologlc LOnes in NigerU weft' Inlesllg,ned l"ht!se ..roelllt$ oi~ exempllfll!t I by the buro I'okkr PiIOlI'roject(zppp)SCI\e ptd the-Sokofo Rlmil RJver Basin Dew:~m,," 1....1ItOOI'1l}' (SRRSDII) Blmin·KrbbL in tlw!SUd m S;n'~nnah;lht Nw~nan S:Comili'rr~tsUCO)esl'ille sc emr,BilcQindlt ;J ",""Cuinr~SavanT-~ na.hz~;olndtheluo . \ R1.:rprojtct,oflhe ~Iha,::!t. is an Inftction c~usrd by parasllic Ogun - O!;un Rlytr ~ Dr-It.'q,menl Aurhorwonns or blood flukes of crrt~m species ollhr II)' (OORBDIIPt me R.Ur fol rst zone. The tffectS genus SChistOSOIDd. Adult p.1m.1tes 1M! in tht of irngalJon dew:loprntnt (;.n Hulth or openblood of ffid.mmals, bUllhelrUrecyrle requim tOllatld inlwblloJlltS II! "ad, orlhl'1or SChf'mti ~ phas.o of ilsexual mulnphcilnon Within a weR studIed. fresh,woJlgrsnall host. The flukes Infed humans As a rcrult 0( tack or dJI.,on prtirrigalion dtwho enter IhelrDposrd skin In water, usually velopmeut he~lth sliIlU of resKlenlS In .!.lIthe through SWImming. b.Jthlngor~ing. Thl'll! schtmes.only post-inigJlkn development exIst:s tltherunJLlltyor mtt'SUnaischu;(OSOlflW. ~ra, where ~v~bb&e,h.,vt' I~ used IP Inle!"'

SIlO. Th~ type and weill of health complications pret thr preY~ltnce oroJlt'lwisr 01 ceftil.in dUo assocu.tM With schistosomiasis appurlOVill)' ~ses In thtueas,whidl m~ybt' used.s wirh sprc\H 01100 smin of p.1ril.Silr a nd by tht' baseline for fuLU~ smd es. charactrrisllaofthe hum~n popul.rion. l NISUCOSci1cme Mr. Vke<hanct'lIor, pe:nnil me to brieflybnng nil' aV.J.Ilablt heahh 11K )rd:.on Ihe NlSUCO loour notiCt a feww.llent poinlS In tht' revi~ scheme Indlcatf'd that Il"itCommon1y reponed on t'fTecu of lnipflon lioI.ms In the prPNaJt'1la GlSt"I wert:: Malaria, D\'s<!ntryfDi.;uThota.. SChlsorbiltwrzw Iri our cootlnent. losomWls. AWYsls. ~ wally TnnsmiLrrd OtsA WHO I'q)Oft ofl978 observed thill un~O' e.ues(STD).and Onchqcm:tuls. f1gul'l!S 14 ~oo schlslO50miaslSWilS practkill!volbSl:'nt bf':fOR t5showth~ numbeorof u,St'J ~poned annUdI!y Akosombo I~kr IRiver Volu. Ghana) was filled ror these dlst.ses around d.e projK1.rta. in 1964. In 1967, ncklence or,he Infection was Millarla., DpK1.ed~ b tl e nlOSt pr~lent With teportl!d In school chikl~n on Ihrte stlectC!d OYer tWO IhousoI.nd (a.se.; JeIXlnM annually. si tes at a ratl! of9X. 3C and 42\ respecuytl~ ReThe hlght"lt number Q("CUIrcd in 1988, ~ ~oI.t in pori bv the Wnt medical tum a}'l'M Ialer rrwhich com~..Ove.Iy 10 jJ r..inU11 •.nd relative ~ed'ttwl the Infernon rate had listn by99X, humldll)'_~ mon,ie(l this lends losuggest.

99S~nd 1411t'Spl'tti~y; that intens~ Irrigilfion mi.Y ~w been cai1ied In Egypt, theconmuction of Aswin High ~m out that ~ilTwith theallendanllnauSt'd also uused KOlogical changes along lht Nile ilS open Wilttr surfaces for molgllitO bRedIng. It encouraKed mail breedlngclOO multlpUc...

Ne!ltt in preYllence on LI,Is st:fIerneo ISdJ:1IliOn. 'Tbe efTect.was tht sprrad of schistosomlaIrry/dlant\Of'a. Thisdist iISt' might be ue 10 the sis OYt'r are.s where only mlkllnfeaion had driIikin8pf tmgation l\o.ler bylirld aisttd.. workmtJdllDft1 during workinl hours in thr In Nigena..,ltlsallOrvident WI Woltrrresourca field de~Jopmt:m projects bilvt made bllhanlas TO 8E COND.UUED