This is the seventh lecture of the course 'Irrigation based Agro-ecosystems' conducted at the Faculty of Social Sciences and Humanities of the Rajarata University of Sri Lanka

1. WRMG 2212
Theory 20 hrs
Practical 20 hrs
Rajarata University of Sri Lanka
P.B. Dharmasena
0777-613234, 0717-613234
dharmasenapb@ymail.com, dharmasenapb@gmail.com
https://independent.academia.edu/PunchiBandageDharmasena
https://www.researchgate.net/profile/Punchi_Bandage_Dharmasena/contributions
http://www.slideshare.net/DharmasenaPb
c,

18. 485 202 416 1,403 509 50 54 70 414 2,112 2,693 1,691 10,099

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22. (3000 – 600 )
( ) ( ) ( )
( )
(2554 – 2517
)
( )

23. bmerKs ,l oi foi

25. % %
10 28
15 16
15 07
16 16
17 07
15 10
12 16
tAldnoaO c, iïm;a l<ukdlrKh mokï
lr.;a mßmd,k udhsï

26. •
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27. 1
2
3 5
3

30. kdÉpd¥j
lkord jej
yqre¿ jej

31. .iaf.dïuk

32. taldnoaO c, iïm;a l<ukdlrKh hkq l=ulao @
• taldnoaO ùu
• úúO c, Ndú;hka tlg f.k ie,lSu'
• Ndú;hkaf.a wfkHdkH n,mEu ie,lSu'
• iEu wxYhlgu .e,fmk mßos m%;sm;a;s ieliSSu'
• ish¿ Ndú;d lrkakkag ^f.dùka" m%cdjka" mßirfõoSka
''''''&' iyNd.s;ajfhka ;SrK .ekSug yelsùu'
• bosß mrïmrdj i|yd os.= ld,Sk ;sridr;ajh ;yjqre
lsÍu'
tAldnoaO c, iïm;a l<ukdlrKh - iudc" wd¾Ól yd
mßird;aul wruqKq i|yd c, iïm;a ;srir f,i ixj¾Okh"
iemhSu iy úu¾Ykh Wfoid jk úêu;a ls%hdj,sh

35. 585 mcm
435 mcm
350 mcm
97 mcm from
Paranki Aru
4,000 acres
can be
cultivated
annually
25%
64 mcm from
Aruvi Aru

36. 1990 2025 2025
1.72
22
70
14
37 %
1.3
70
2.49
35
70
23
37 %
1.3
112
2.49
35
100
17
45 %
1.6
70

37. c, kdia;sh
osia;s%lal fhdackdl%uh fnodyßk
,o ^uilg
>k óg¾&
Ndú; l<
^uilg >k
óg¾&
] ydksh
fld<U fld<U 8,913,925 4,407,044 50.6
uykqjr ydr.u 71,134 39,337 44.7
yïnkaf;dg w.=Kfld<
me,eiai
68,230 46,396 32.0
mq;a;,u y,dj; 125,228 99,782 20.3
mq;a;,u mq;a;,u 218,018 150,585 30.9
mq;a;,u oxfldgqj 24,578 14,181 42.3
Source:NWSDB

38. •
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taldnoaO c,
iïm;a
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IWRM

39. taldnoaO c, iïm;a l<ukdlrKfha l=¿Kq ;=k
Three pillars of IWRM
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45. (54%)
(18%)
(13%)
(15%)

46. (3%)
(87%)
(8%)
(2%)

47. 0.3%
72.6%
18.5%
8.6%

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49. 0
10
20
30
40
50
60
70
80
90
0
5
10
15
20
25
30
1870 1920 1970 2020

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Dublin, 1992

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58. • rch jHdmD;shla l%shd;aul lrkafkl=g jvd myiq lrjkafkla
iy md,lfhla úh hq;=h
• tAldnoaO c, iïm;a l<ukdlrKfha oS .x.dfødaKsh tys
;d¾lsl N+f.da,Sh tAllh njg m;afõ
• wdh;ksl ieliSï wjYH jkafka
– ;SrK .ekSu" iudcfha ish¿u fldgia j, ksfhdackh jk fia
md¾Yjlrejkaf.a ;=jla
– c, úoHd;aul iSud mokï fldg .;a c, iïm;a
l<ukdlrKhla
– fødaKs iy WmfødaKs uÜgfï ixúOdk jHqyhka
– ish¿u c, Ndú; lrkakkaf.a l%shdoduh i|yd cd;sl lñgqjla
iïnkaëlrKh i|yd rdcH ueosy;a ùu

59. 59

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64. ld¾hNdrh iy j.lSu

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67. • wksjd¾h
– jHdmD;s l<ukdlrKh iy lKavdhï kdhl;ajh
– ikaksfõok iy idlÉPd l=Y,;d
– mßmd,kuh iydh
• wNsu;
– c,iïm;a ie<iqï lsÍu iy ixúOdkh
– foaYmd,ksl" wdh;ksl iy ffk;sl l=Y,;d
– ;dCIK l=Y,;d ^c, úoHd" b,a¨u we.hSu wdosh&
– iudc wd¾Òl úYaf,aIKh
– wd¾Òl iy uQ,Huh

68. •
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71. 
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72. mdrAYjlrejka iyNd.S lr .ekSfñ
mshjrhka
 m%Odk mdrAYjlrejka
y¥kd .ekSu'
 mdrAYjlrejkaf.a
Wkkaÿj we.hSu iy ta
khska jHdmD;shg
we;s jk n,mEu'
 mdrAYjlrejkaf.a
n,mEu iy jeo.;alu'
 iyNd.S;aj WmdhudrA.
fm< .eiau'

73. 
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