11/18/2011 1 Drainage in IRAN; 21 st International Congress on Irrigation and Drainage Drainage in IRAN; A Country Report ARDAVAN AZARI ARDAVAN AZARI Drainage & Environment Working Group of IRNCID Tehran‐ October 2011 Area: 1.648 million km 2 P l ti 75 illi Population: 75 million No. of provinces: 31 Average Rainfall: 271 mm Cultivable Area: 51 million ha Potentially good & moderately good Crop land: 37 million ha Cultivated area : 18.5 million ha Cultivated area : 18.5 million ha Irrigated area : 8 million ha •Mean rainfall Mean rainfall 1/3 of world mean rainfall of world mean rainfall •Mean evaporation Mean evaporation 3 times of mean world times of mean world evaporation evaporation Khazar Uromieh 70 70% of of rainfall rainfall over over 25 25% of lands of lands Rainfall Rainfall 75 75% non non‐irrig irrig. season . season Central Basin 160 2770 361 Khazar 464 1588 395 1610 Ghareh ghoom 240 2171 hamoon 132 3051 (fall (fall‐winter) winter) 25 25% irrig irrig. season . season (spring (spring‐summer) summer) 2899 Rainfall: Evaporation: 361 2899 Modern Irrigation & Drainage Networks in Iran Total irrigated area in Iran 8 million ha Main Irrigation Canals – million ha Total On study phases Under construction Constructed 3.91 1.84 0.27 1.8 47% On study phases 47% 7% 46% Under construction
Transcript
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Drainage in IRAN;
21st International Congress on Irrigation and Drainage
Drainage in IRAN;A Country Report
ARDAVAN AZARIARDAVAN AZARI
Drainage & Environment Working Group of IRNCID
Tehran‐ October 2011
Area: 1.648 million km2
P l ti 75 illiPopulation: 75 million
No. of provinces: 31
Average Rainfall: 271 mm
Cultivable Area: 51 million haPotentially good & moderately
good Crop land: 37 million haCultivated area : 18.5 million haCultivated area : 18.5 million ha
Irrigated area : 8 million ha
••Mean rainfall Mean rainfall 11//33of world mean rainfallof world mean rainfall
••Mean evaporation Mean evaporation 33times of mean world times of mean world evaporationevaporation
KhazarUromieh
7070%% of of rainfallrainfall
overover
2525%% of landsof lands
RainfallRainfall7575%% nonnon‐‐irrigirrig. season . season
Central Basin1602770
361
Khazar4641588
3951610
Ghareh ghoom2402171
hamoon
1323051
(fall(fall‐‐winter)winter)
2525%% irrigirrig. season . season
(spring(spring‐‐summer)summer)
2899
Rainfall:Evaporation:
3612899
Modern Irrigation & Drainage Networks in Iran
Total irrigated area in Iran 8 million ha
Main Irrigation Canals – million ha
TotalOn study phases
Under construction Constructed
3.911.840.271.8
47%On study phases
47%
7%
46%
Under construction
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Continue …Modern Irrigation & drainage Networks in Iran
RemainderOn study Under Constructed
On-Farm Irrigation Network- million ha
areaphases construction Constructed
2.130.900.080.82
2% ConstructedUnder construction
54%23%
2% 21%
On study phases
Remainder area
Iranian National Committee on Irrigation & Drainage (IRNCID)
Drainage challenges sessionswith collaboration of many drainage experts of the country
• First session(2001) Modification of drainage rate• Second session(2002) controlled water table• Third session(2004) Hydraulic conductivity & challenges • Fourth session (2006) Improvement of drained water• Fifth session(2007) Drain envelopsFifth session(2007) Drain envelops• Sixth session (2010) Drainage challenges in Khuzestan• Seventh session(2011) Use of models on drainage
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Subsurface Drainage In IRAN
• Backgrounds
• Present conditions
• Our experiences
• Our modifications
• Urgent need to drainage in the country
Subsurface drainage in Iran
Backgroundsfirst modern Irrigation & drainage network,1932
southern part of the country(Bushehr & Khuzestan)
Open drains(machine made) 1956 Shavoor, Khuzestan
Tile drains (by trenchers),1963 Ahvaz(Mollasani) 500 ha
Hafttappeh project 1960s North Khuzestan, 11000 ha
Army pilot farm, 1970s East Mazandaran, 7000 ha
Karoon project 1970s Khuzestan 24000 ha
Voshmgir project,1970s East Mazandaran 18000 ha
TotalDesignedUnderconstructtion
constructed
Deep open drains
Subsurfacedrains
General view of drainage in IRAN – year 2011
536,000236,00060,00026,000214,000
Total existing drained area240,000
Designed, 236,000Subsurface
drains, 214,000
Under
constructtion, 60,000
Deep open
drains, 26,000
The location of drainage projects in IRAN Constructed or
Under construction
Designed
Kuzestanprovince
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140,000 ha (58%) Khuzestan region
100,000 ha (42%) other parts
240,000 ha (100%) Total present drained area in IRAN
Present drainage networks
100,000 ha (42%) other parts
Khoozestanprovince58%
other regions42%
Under construction30,000 ha in Khoozestan
30,000 ha in other parts
Khuzestanprovince
Khuzestanprovince
TotalDesignedunder Under
Present condition & view of drainage in near future in KHOOZESTAN
TotalDesignedconstructionoperation
406,000236,00030,000140,000
Designed
Underoperation
34%Designed 59%
Underconstruction
7%
The sugarcane has a main role of drained area in Khuzestan:
Type of drains: Mostly subsurface pipe drains. (deep open drains alsoexists)
Type of pipes : Corrugated & perforated plastic pipes. (in the past, tile &yp p p g p p p p ( p ,concrete pipes also used)
Envelope materials: Sand & gravel. (recently synthetic envelopsalso used, but not yet evaluated).
Installation technique: Trenchers with laser grade control.( in the past backhoe & excavators also used)
Type of collectors: Mostly concrete pipes. (some open drains also used)Inspection system: Manholes & flushing pipe system.Inspection system: Manholes & flushing pipe system.Drain installation depth: In the past 2.2 to 2.5; recently 1.5 to 1.8 mControlled water table depth: In the past 1.2 to 1.5; recently 0.8 to 1 mDrainage rate: In the past 3 to 6; recently reduced up to 2 mm/day
Drainage in Moghan regionDeep open drain
Open collector(singular
system)SubsurfaceDrain outfall
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of field investigationsTwo different characters of waterlogged areas of Iran
A: The wide & low slope plains
Drainage is necessary if irrigation is done.Drainage must start when irrigation begins.Drainable area is the same as the irrigation area.The location of drained area follow the irrigated area
B: The alluvial plains with or without lowland on downstreamB: The alluvial plains with or without lowland on downstream
Not always drainage necessary if irrigation is done.The drainage problems appear few years after introduction of irrigation.Drainage is need only in the part of area(downstream).The location of drainable area may not follow the irrigated area.
Samples of two types of drainable area in IRAN
A: flat plains with low level ground water B:Alluvial plains, lowland area on downstream
lakeWaterlogged area
All the area need drainage
Waterlogged areaAll the area need drainage
Slopping upland irrigated area
L l l l dLow slope lowland waterlogged area
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About 60 years experience of design & implementation ofmodern drainage exists in Iran.
More than 30 years of our experiences are absolutely withIranian consultant & contractors.
We have both successes and failures about planning, design,
construction and operation of drainage projectsconstruction and operation of drainage projects.
Nowadays we are modifying some of our criteria on bothdesign and construction of the drainage projects.
Nowadays all drainage works could be done by Iranianexperts.
The laterals installed alternately in some projects ,the results was Okthe results was Ok.
Causes:Over estimated Drainage rate.Not counted the direct discharge of the collectors & deep openNot counted the direct discharge of the collectors & deep open
drains
projectYearDrainage
rate(mm/day)5.0
6.0
7.0
Examples of reducing of drainage rate in the recent years
Sugarcanedeveloping19995‐6
Dalaki20003.5
Moghan20012.6
behbahan20012.5
Shadeghan20102
SalamatUnder construction2
0.0
1.0
2.0
3.0
4.0
Drainage rate
(mm/day)
1999 2011projects
Ra’d-kosarUnder construction2
vaisUnder construction2
Nowadays the drainage projects are designed with drainage rate of about 2 mm/day
projectYear Installation
depth( )
2.5
les of reducing of drain installation depths in the recen
(m)Moghan19802.2
SugarcaneDevelopment co.19991.8
Dalaki20002.2
Moghan20012.2
behbahan20012.2
Shadeghan20101.60.0
0.5
1.0
1.5
2.0
Inst
alla
tion
dept
h -m
SalamatUnder construction1.5
Ra’d-kosarUnder construction1.5
vaisUnder construction1.5
1980 2011
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Our experiences in alluvial plains with lowland in downstream
Constructing the deep open drains in depressions, instead the pipedrains, in some plains; drainage problem reduced or solved completely.
Drains installed only in the part of waterlogged area( downstream &critical waterlogged); the problem solved in other parts.
constructing the local open drains through the natural slope , shift theg p g pproblem to the uncultivated desert area on downstream
Our Urgent Needs of Subsurface Drains in the country
700 000 h d d i i ti t k700,000 ha. under modern irrigation networks (Rough estimated)
400,000 ha. in Khuzestan including 350,000 in Karkheh basin
