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HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan C 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural Hydrology in Northeast Thailand FUKUI Hayao Faculty of Agriculture Khon Kaen University, Thailand
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HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Dec 29, 2015

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Page 1: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

HOSHIKAWA KeisukeCenter for Integrated Area StudiesKyoto University, Japan

PNC 2011 Annual Conference and Joint Meetings

Thamnop Irrigation and Natural Hydrology in Northeast Thailand

FUKUI HayaoFaculty of AgricultureKhon Kaen University, Thailand

Page 2: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Northeast Thailand:a rain-fed rice cultivation area

Northeastern Region

0

5,000,000

10,000,000

15,000,000

20,000,000

25,000,000

30,000,000

35,000,000

40,000,000

45,000,000

50,000,000

1933 1943 1953 1963 1973 1983 1993

rai

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

8,000,000

9,000,000

10,000,000

ton

0 200km0 200km0 200km

Rice planted area

Rice production

0.0 - 0.10.1 - 0.20.2 - 0.30.3 - 0.40.4 - 0.50.5 - 0.60.6 - 0.70.7 - 0.80.8 - 0.90.9 -

Irrigation project area/rice cultivation area

However, Northeast Thailand also has history and tradition of irrigation for rice cultivation.It was widely practiced before the expansion of rice area.Still in use.

Page 3: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

How is Thamnop irrigation?

“…paddy fields in Phanchana District mostly depend on water from thamnop as this district has many streams. Lam Chiang Krai River is one of the most important streams. Some thamnop on it are supplying water to paddy fields. If there are no thamnop in the district, rice cultivation should depend only on rainfall, and transplantation has not finished by until this month…”

Report of Ministry of Agriculture in 1912 (KS13/743 )

How is the thamnop irrigaion that played important roles in rice cultivation in the past?

Thamnop (ทำ��นบ): dike, dam, embankment, weir“Structures that block stream flow and prevent water from flowing downstream (สิ่��งก่�อสิ่ร้��งก่��นลำ��น���ไม่�ใหลำผ่��น)”

Page 4: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Topics

• How is thamnop irrigation?• How does it work?

– Structure and function different from “ordinary” irrigation weirs

• Why thamnop?– Local hydrological environment and thamnop

Page 5: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Earthen weir that block up rivers completely

How is Thamop?

Thamnop NonburiSurin Province, Thailand

Especially seen in Southern part of Northeast Thai and around Siemriap, Cambodia

Page 6: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Thamnop Khon MuangNakhon Ratchasima Province,Thailand

Page 7: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Blocked rivers sometimes make a detour channels

Buriram ProvinceThailand

Page 8: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Former river channel

Page 9: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Thumnup (Thamnop) around Ankor Wat

Angkor Wat

West Barai

East Barai

Page 10: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

North of West Barai

Page 11: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.
Page 12: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.
Page 13: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.
Page 14: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Stream flow is blocked completely with an embankment longer than width of river channel

Characteristics of Thamnop

Almost whole stream water directly flows into paddy fields around thamnop

Flooded water reaches sometimes several kilometers from a thamnop

Page 15: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Characteristics of Thamnop irrigation systems

Structure• They block up streams completely with

embankments that are often several times longer than width of river channels.

• No water gate to regulate water intake.

Function• Quantity of water intake is not controllable.• It depends on amount of river runoff.• As a consequence, thamnop often make flood

damage on rice plants.

Page 16: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

They sometimes cause flood damage on rice plants.

Characteristics of Thamnop

Page 17: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Image search for “weir”

File:Revin Meuse weir 20041230- 024.jpgFrom Wikipedia, the free encyclopedia

“Ordinary” weirs: raise and maintain river water level, but not block flow completely (allow overflow)

“Ordinary” weir

Page 18: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

“Ordinary” diversion weir

Weir that can release excess water

Water gate that regulate quantity of water intake

Diversion channel to send water to paddy fields

Spillway along a diversion canal to discharge excess water in a channel

Sophisticated system to take stable (or intended) amount of water from rivers

“Ordinary” weir

Page 19: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Traditional weir irrigation system

“Ordinary” weir

Myanmar, Jan 2003

Design and functions are basically same.

Page 20: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Spatial distribution of Thamnop irrigation

0m

900m

Weir irrigation

thamnop

Thamnop are constructed along “montainless” rivers

Page 21: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Hydrology of mountainless riversRunoff velocity

Sensitivity to rainfall

Runoff ratio(runoff/rain)

Shape of peaks

Rivers in plain areas(thamnop)

Low Low Low Gradual low peaks

Rivers in mountainous areas(weir irrigation)

High High High Sharp high peaks

Why thamnop?

Evaporation

Runoff (observed)

Rainfall

Runoff (initial)

Runoff ratio =Runoff/Rainfall

Page 22: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Hydrology of mountainless riversRunoff velocity

Sensitivity to rainfall

Runoff ratio(runoff/rain)

Shape of peaks

Rivers in plain areas(thamnop)

Low Low Low Gradual low peaks

Rivers in mountainous areas(weir irrigation)

High High High Sharp high peaks

Dai

ly ru

noff

(m3/

s)

Prec

ipita

tion

(mm

/d)

1995

Precipitation

Runoff

Mun Riv., Northeast Thai (thamnop)

390km2 (M101)Annual prec:1180mmAnnual runoff:233mm

Runoff ratio:0.20

Ping Riv., North Thai (weir irrigation)515 km2 (P021)

Annual prec:1180mmAnnual runoff:369mm

Runoff ratio:0.31

Why thamnop?

Page 23: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Quick runoff and slow runoffRainfall

Quick runoff (surface runoff)

Slow runoff(subsurface)

Stream

Base runoff

Peak runoff

Rainfall

Runoff

Why thamnop?

Page 24: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Hydrology of a weir irrigation river

• Runoff consists of peak flow and base flow.• Stable and rich base flow.

There is no reason to dare to use peak runoff, as peaks are sharp and short lasting.

Why thamnop?

Page 25: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Hydrology of a thamnop irrigation river

• Difficult to separate base flow and peak flow because of long lasting low peaks and unstable base flow

• Water resource is rather limited because of low runoff ratio.

It is better to take whole runoff at every moment

Why thamnop?

Page 26: HOSHIKAWA Keisuke Center for Integrated Area Studies Kyoto University, Japan PNC 2011 Annual Conference and Joint Meetings Thamnop Irrigation and Natural.

Conclusions

• Thamnop irrigation much depends on river runoff.

• This does not mean that thamnop irrigation is less efficient than weir irrigation.

• The thamnop irrigation system is well designed by local people for mountailess rivers.