Transcript Monetary Assessment of the Multifunctional Roles of Paddy

Monetary Assessment on
Multiple Functions of Irrigation Water
for Paddy Fields
in the Asian Monsoon Region
March 18, 2009
Kazumi YAMAOKA, PhD
International Network for Water and
Ecosystems in paddy fields (INWEPF)
Background of monetary assessment
Multiple functions of irrigation services provide huge benefit to many
beneficiaries in addition to farmers.
Flood mitigation, Ground water recharge, Preventing soil from erosion,
Bio-diversity Stabilizing downstream river flow, Recreation, and etc.
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.
Implement appropriate water
policy by government
Support by NGO and
other non-farmers
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
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Multiple Functions of Water Management in Paddy Fields
Flood mitigation
Heavy rain in river basin
Temporary water storage
during heavy rainfall
Flood mitigation
Diverted water
from rivers
Drainage canal
Agricultural road
Irrigation canal
Drainage
Infiltration
Retardant flow to
downstream rivers
Flood mitigation
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Multiple Functions of Water Management in Paddy Fields
Recharge of river flow and groundwater
Heavy rainfall
Oceans
Seas
Rivers
Irrigation canal
Drainage canal
Agricultural road
Ground water level
Infiltration
Drainage
River
Recharging groundwater
Stabilizing river flow
Conservation of aqua-ecosystem
Re-use or Recycle of water for
other sectors/users
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Multiple Functions of Water Management in Paddy Fields
Prevention of soil erosion and land slide
Irrigation canal
Drainage canal
Levees around paddy fields and
standing pool of water in paddy
fields protect farm soil from
erosion caused by heavy rain.
Agricultural road
Rain
Rain
Direct impact
from heavy rain
Soil erosion
Slope
Stabilizing infiltration
at moderate level
Easing of pore
water pressure
Prevention
of land slide
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Multiple Functions of Water Management in Paddy Fields
Formation of aquatic ecosystem
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.
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Multiple Functions of Water Management in Paddy Fields
Formation of social capital, culture and traditional events
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.
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Calculation Methodology
INWEPF, studied a trial calculation of the monetary
assessment on 3 major multiple functions
・Flood mitigation function
・Groundwater recharge function
・Soil erosion prevention function
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Calculation Methodology
(1)Calculation Method:
Replacement Cost Method (RCM)
Example: Flood mitigation function
Monetary value
Annual amount of
available water volume
depreciation cost per unit
=
× efficient storage capacity of
stored
reservoirs
by paddy field
(USD/m3/year)
(2) Data Collection:
Sending the questionnaire to the INWEPF
member countries in July, 2008 and January,
2009.
(But some data couldn’t be collected.)
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Results of Assessment
Annual Mometary Value
Country
Flood
Groundwater
prevention
recharge
Soil
erosion
inhibiting
Rice
production
value
Total
Mill. USD
Mill. USD
Mill. USD
Mill. USD
USD/ha
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
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
32,746
9,693
1,305
43,744
1,340
Japan
Indonesia
Total / Average
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Results of Study
• Monetary assessment on 3 multiple functions of irrigation water
for paddy fields can be carried out by RCM.
• 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.
• 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.
• 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.
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(Reference) The way to assess multifunctional roles
of paddy fields
a) Flood Mitigation function
STEP1
Calculation of
function volume
available water volume stored
by paddy fields
Efficient capacity
×
STEP2
Calculation of
unit monetary value
Unit annual
monetary value of
flood prevention
function of 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)
Monetary Assessment of the Multifunctional Roles of Paddy Fields
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b) Groundwater Recharge function
STEP1
Calculation of
function volume
the ground water recharge volume
from paddy field out of using
ground water volume
The groundwater
recharge volume
×
STEP2
Calculation of
unit monetary value
Unit substitution
cost
calculated by area of paddies, daily
water requirement rate of paddy
fields, annual precipitation, etc
×
Water rate (USD/m3)
(price of domestic water)
Monetary Assessment of the Multifunctional Roles of Paddy Fields
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c) Soil erosion prevention function
STEP1
Calculation of
function volume
Different volumes between soil
erosion volumes at cultivation
abandonment and them as usual
(USLE method)
Soil erosion
volume prevented
×
STEP2
Calculation of
unit monetary value
Unit labor cost to
excavate soil
eroded
calculated by area of paddies,
annual precipitation, slop length,
steepness, etc
×
Labor cost (USD/m3)
Monetary Assessment of the Multifunctional Roles of Paddy Fields
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Diagram for categorizing multi-functionality
Multifunctionality of water collectively managed for
paddy rice agriculture
A. Benefits spread to public society through agricultural activity
A-1. Benefits automatically generated to the public
Protect aqua-ecosystem, enhance water-related environment,
form landscape, recharge groundwater aquifer, mitigate
damage by flood, stabilize downstream river, etc.
A-2. Benefits intentionally provided to the public
･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.
B. Benefits gained by farmers and local community
B-1. Multi-purpose use of water by farmers
Aquaculture, duck raising, washing, cleaning, bathing,
cooling, gardening, fire fighting, etc.
B-2. Supporting local cultural-religious activities
Socio-economic development in Asian countries versus
value of multifunctionality categorized into four characters
A-2. Benefits intentionally
provided to the public
A-1. Benefits automatically
generated to the public
B-1. Multi-purpose use of
water by farmers
B-2. Supporting local cultural-religious activities
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