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Monetary Assessment on Multiple Functions of Irrigation Water for Paddy Fields in the Asian Monsoon Region
March 18, 2009
Kazumi YAMAOKA, PhDInternational Network for Water and Ecosystems in paddy fields
(INWEPF)
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Background of monetary assessment
Multiple functions of irrigation services provide huge benefit to many beneficiaries in addition to farmers.
To share the broadened concept of Multiple Uses and Functions (MUFs) of irrigation water by policy makers and tax payers, monetary assessment can be a tool to make its value virtually visible.
Flood mitigation, Ground water recharge, Preventing soil from erosion, Bio-diversity Stabilizing downstream river flow, Recreation, and etc.
Promoting momentum and sustainable activities which aim at efficient and equitable water use consistent with the regional and socio-cultural needs → Accelerate to achieve MDG’s target
Implement appropriate water policy by government
Support by NGO and other non-farmers
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Retardant flow to downstream rivers
Multiple Functions of Water Management in Paddy Fields
Flood mitigation
Infiltration Drainage
Flood mitigation
Temporary water storage during heavy rainfall
Heavy rain in river basin
Drainage canal
Diverted water from rivers
Irrigation canal
Agricultural road
Flood mitigation
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Multiple Functions of Water Management in Paddy Fields
Recharge of river flow and groundwater
Ground water level
Infiltration Drainage
River Stabilizing river flow
Recharging groundwater
Drainage canal
Agricultural road
Conservation of aqua-ecosystem
Re-use or Recycle of water for other sectors/users
Irrigation canal
Heavy rainfall
Rivers Oceans Seas
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Multiple Functions of Water Management in Paddy Fields
Prevention of soil erosion and land slide
Levees around paddy fields and standing pool of water in paddy fields protect farm soil from erosion caused by heavy rain.
Stabilizing infiltration at moderate level
Rain
Slope
Soil erosion
Drainage canal
Agricultural road
Irrigation canal
Rain
Direct impact from heavy rain
Easing of pore water pressure
Prevention of land slide
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Multiple Functions of Water Management in Paddy Fields
キンブナドジョウ
トウキョウダルマガエル
ゲンゴロウ メダカ
The water network (corridor) connecting irrigation canal, paddy fields, ponds and woods is formulated around paddy fields.
Through this network, aquatic ecosystem with a rich flora and fauna is formed.
Formation of aquatic ecosystem
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Multiple Functions of Water Management in Paddy Fields
Farmers have recognized irrigation canals as a social overhead capital. And their collective water management, such as allocation of water and maintenance of irrigation structures, has inevitably promoted community systems and social capital among them.
The water management has also been a base of traditional ceremonies, rituals and cultures with respect or worship to water and the nature.
Formation of social capital, culture and traditional events
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INWEPF, studied a trial calculation of the monetary assessment on 3 major multiple functions
・ Flood mitigation function ・ Groundwater recharge function ・ Soil erosion prevention function
Calculation Methodology
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Calculation Methodology
available water volume stored
by paddy field
Annual amount of depreciation cost per unit
efficient storage capacity of reservoirs
(USD/m3/year)
(1)Calculation Method: Replacement Cost Method (RCM)
(2) Data Collection: Sending the questionnaire to the INWEPF
member countries in July, 2008 and January, 2009. (But some data couldn’t be collected.)
Example: Flood mitigation function
Monetary value = ×
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Results of Assessment
Floodprevention
Groundwaterrecharge
Soilerosion
inhibitingTotal
Mill. USD Mill. USD Mill. USD Mill. USD USD/ha
Japan 27,157 586 327 28,070 8,783
Bangladesh 199 8 38 246 531
Cambodia 46 5 17 68 364
China 812 3,111 45 3,969 943
Egypt 24 0.3 0 24 2,363
India 1,293 1,867 147 3,306 472
Indonesia 294 382 266 942 962
Korea 1,038 145 27 1,210 3,371
Laos 15 3 5 23 425
Malaysia 106 24 33 162 702
Myanmar 49 41 50 140 463
Nepal 34 12 8 53 423
Pakistan 53 1,494 0 1,547 677
Philippine 171 1,440 127 1,738 647
Sri Lanka 68 20 4 92 565
Thailand 1,240 65 164 1,469 487
Viet Nam 147 490 47 684 594
Total / Average 32,746 9,693 1,305 43,744 1,340
Riceproduction
valueCountry
Annual Mometary Value
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Results of Study
• In the next step, refining the assessment and applying it to other functions are expected. Developing the tool for appreciating a holistic value of irrigation systems for rice paddy fields must realize more sustainable rice production in the future and contribute not only to eradicating hunger and poverty but also to solving global issues on food and energy.
• According to the trial assessment over 17 countries, the annual value of only 3 multiple functions out of various them are more than 800 USD/ha in average in addition to rice production value.
• Monetary assessment on 3 multiple functions of irrigation water for paddy fields can be carried out by RCM.
• Because of wide range of beneficiaries on the holistic value, it is important to facilitate sustainable investment by pubic sectors to irrigation systems for paddy fields.
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(Reference) The way to assess multifunctional roles of paddy fields
a) Flood Mitigation function
STEP1 Calculation of
function volume Efficient capacity
STEP2Calculation of
unit monetary value
Unit annual monetary value of flood prevention function of paddy
fields
Monetary Assessment of the Multifunctional Roles of Paddy Fields
×
available water volume stored by paddy fields
calculated by area of paddies, level of height of levee in average, etc
Annual amount of depreciation cost per unit efficient storage capacity of
reservoirs(USD/m3/year)
×
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STEP1 Calculation of
function volume
STEP2Calculation of
unit monetary value
Monetary Assessment of the Multifunctional Roles of Paddy Fields
×
the ground water recharge volume from paddy field out of using
ground water volume
calculated by area of paddies, daily water requirement rate of paddy fields, annual precipitation, etc
Water rate (USD/m3)(price of domestic water)
×
b) Groundwater Recharge function
The groundwater recharge volume
Unit substitution cost
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STEP1 Calculation of
function volume
STEP2Calculation of
unit monetary value
Monetary Assessment of the Multifunctional Roles of Paddy Fields
×
Different volumes between soil erosion volumes at cultivation
abandonment and them as usual(USLE method)
calculated by area of paddies, annual precipitation, slop length,
steepness, etc
Labor cost (USD/m3)
×
c) Soil erosion prevention function
Soil erosion volume prevented
Unit labor cost to excavate soil
eroded
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Monsoon and steep topography gives ample rainfall in the rainy season
Note: Mean in 1971-2000 Source: WMO
San FranciscoRoma
N.Y.
LondonBerlin
Yangon
Tokyo
Shanghai
Seoul
Kuala Lumpur
Bangkok
Ha Noi
DhakaColombo
Jakarta
• The rainy season exists in monsoon Asia
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Monsoon and steep topography gives ample rainfall in the rainy season
Note: Mean in 1971-2000 Source: WMO
San FranciscoRoma
N.Y.
LondonBerlin
Yangon
Tokyo
Shanghai
Seoul
Kuala Lumpur
Bangkok
Ha Noi
DhakaColombo
Jakarta
• The rainy season exists in monsoon Asia
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Humid climate in monsoon Asia characterizes…
• Nature side : Dynamic oscillation in water cycle •High precipitation and high evapo-transpiration affected by monsoon climate•Quick runoff in great number of river basins with steep geo-topography
Precipitation
(Average 1961-1990)
(mm/year)
2000
0
500
1000
1500
(mm/year)
1000
0
250
500
750
Actual Evapotranspiration
(Average 1961-1990)
• Human side : Strong ties and interaction with water cycle•High population density based on paddy rice agriculture
•Vast multiple values generated by multi-functional roles of agricultural water
•Traditionally developed agricultural water governance during drought and flood
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Monsoon Asia - Major production area of rice in the world
Source: FAOSTAT, Oxford Economic Atlas
Asia
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Importance of paddy rice production supporting massive population in monsoon Asia
Distribution of rice producing areaDistribution of rice producing area Distribution of population densityDistribution of population density
Proportion of rice to total calorie intake in countries and regionsProportion of rice to total calorie intake in countries and regions
Source ： IRRI: Atlas of Rice & World Rice Statistics, http://www.irri,org/science/ricestat/index.asp FAO: FAOSTAT, http://faostat.fao.org/faostat/collections?version=ext&hasbulk=0
About 54% of the world’s population survives in about 14% of the world’s terrestrial area
Country / region Bangladesh Cambodia Indonesia Japan Korea Rep Laos Myanmar Viet nam Asia Non-Asia World
Proportion of calories supplied by rice (%) 72 75 50 23 31 66 71 66 31 3 20
Population (mil.) 138 13 212 127 47 5 48 78 3,680 2,391 6,071
Source: FAOSTAT, Oxford Economic Atlas
Aquaculture, duck raising, washing, cleaning, bathing, cooling, gardening, fire fighting, etc.
Protect aqua-ecosystem, enhance water-related environment, form landscape, recharge groundwater aquifer, mitigate damage by flood, stabilize downstream river, etc.
･ Provide water from agriculture for domestic use during severe dry spells･ Increase performance of paddy fields as outflow-retarding reservoirs during extreme floods･ Create winter sanctuaries for migratory birds･ Restore groundwater level for downstream city, etc.
Multifunctionality of water collectively managed for paddy rice agriculture
A. Benefits spread to public society through agricultural activity
A-2. Benefits intentionally provided to the public
A-1. Benefits automatically generated to the public
B. Benefits gained by farmers and local community
B-1. Multi-purpose use of water by farmers
B-2. Supporting local cultural-religious activities
Diagram for categorizing multi-functionality
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B-1. Multi-purpose use of water by farmers
A-1. Benefits automatically generated to the public
A-2. Benefits intentionally provided to the public
B-2. Supporting local cultural-religious activities
Socio-economic development in Asian countries versus value of multifunctionality categorized into four characters
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Twin Spirals of Interaction between Governance and Social CapitalTwin Spirals of Interaction between Governance and Social Capital
Farmer
Farmer
FarmerFarmer
Farmer
Farmer
Farmers
Experience on
Governance
Experience on
Governance
A ： Spiral between governance on services for water distribution and social capitalB ： Spiral between governance on maintenances for infrastructure and social capital
A ： Spiral between governance on services for water distribution and social capitalB ： Spiral between governance on maintenances for infrastructure and social capital
Accumulation of Social
Capital
Accumulation of Social
Capital
Level
of
Govern
an
ce
Level
of
Socia
l C
ap
ital
A
AB
B
Government(Specialized
body) cashtechnique
cashtimelabor
A mechanism for enhancing governance and A mechanism for enhancing governance and accumulating social capitalaccumulating social capital
2323
Chart at the lower left provides negative correlation coefficients Chart at the lower left provides negative correlation coefficients between amount of water reserved in Makio reservoir and water-between amount of water reserved in Makio reservoir and water-saving ratiosaving ratio
Chart at the lower right shows that fluctuation of shadow price of water Chart at the lower right shows that fluctuation of shadow price of water at source level at source level
Temporary water transfer during abnormal dry spells brings enormous Temporary water transfer during abnormal dry spells brings enormous benefit to citiesbenefit to cities
Linear app.(1982)
Linear app.(1994)
Linear app.(2001)
highhigh Shadow price of water Shadow price of water lowlow
Relation between amount of water reserved and ratio on reduced amount of agricultural water discharged from Makio reservoir in 1982/1994/2001
Change of ratio on reduced amount of agricultural water discharged from Makio reservoir in 1982/1994/2001
low
h
igh
low
h
igh
S
ha
do
w p
rice
of
wa
ter
Sh
ad
ow
pric
e o
f w
ate
r
W
ate
r-sa
vin
g r
atio
(%
)W
ate
r-sa
vin
g r
atio
(%
)
2424
Total number of days under water- saving
0
50
100
150
200
250
300
350
400
450
5 10 15 20 25 30 35 40 45 50 55 60 65
Water- saving ratio for agricultural use (%)
Tota
l num
ber o
f day
s (d
ays)
Water- saving ratio for agricultural versus domesticuse in discharge from Makio dam reservoir
0
5
10
15
20
25
30
35
40
45
50
55
60
65
0 5 10 15 20 25 30 35 40 45 50 55 60 65
Water- saving ratio for agricultural use (%)
Wat
er-
savi
ng
ratio for
dom
est
ic u
se (%)
Water transferred from agricultural use to domestic use
About 800 days per 30 years
Water-saving ratio for agricultural versus domestic use in discharge from Makio dam reservoir (1973-2002)
Makio dam counts during 30 years (1973–2002) ;Makio dam counts during 30 years (1973–2002) ;
20 years when the discharged volume of 20 years when the discharged volume of water was restricted at a water-saving ratiowater was restricted at a water-saving ratio
16 years when the water-saving ratio for 16 years when the water-saving ratio for agriculture exceeded 20%agriculture exceeded 20%
15 years when agriculture granted water to 15 years when agriculture granted water to domestic use during abnormal dry spells by domestic use during abnormal dry spells by setting a relatively higher water-saving ratiosetting a relatively higher water-saving ratio
Repeated temporary water Repeated temporary water transfer in Aich-yousui systemtransfer in Aich-yousui system
愛知用水地区農業用水節水率（１９７３年～２００２年）
0
10
20
30
40
50
60
70
48昭
和49
昭和
50昭
和51
昭和
52昭
和53
昭和
54昭
和55
昭和
56昭
和57
昭和
58昭
和59
昭和
60昭
和61
昭和
62昭
和63
昭和
1平
成2
平成
3平
成4
平成
5平
成6
平成
7平
成8
平成
9平
成 10平
成11
平成
12平
成13
平成
14平
成
農業
用水
節水
率（％
）
夏季冬季
Annually highest water-saving ratio (1973-2002)
wat
er-s
avin
g r
atio
(%
)
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
Summer
Winter
