Monetary Assessment on Multiple Functions of Irrigation Water for Paddy Fields in the Asian Monsoon Region

1. 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)

2. 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. Support by NGO and other non-farmers Implement appropriate water policy by government 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

3. 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

4. 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 Recharging groundwater Drainage River Stabilizing river flow Conservation of aqua-ecosystem Re-use or Recycle of water for other sectors/users

5. 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

6. トウキョウダルマガエル キンブナ ドジョウ ゲンゴロウ メダカ 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.

7. 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.

8. 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

9. Calculation Methodology • Calculation Method: • Replacement Cost Method (RCM) Example: Flood mitigation function Monetary value available water volume stored by paddy field Annual amount of depreciation cost per unit efficient storage capacity of reservoirs (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.)

10. Results of Assessment

11. 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.

12. (Reference) The way to assess multifunctional roles of paddy fields a) Flood Mitigation function available water volume stored by paddy fields calculated by area of paddies, level of height of levee in average, etc STEP1 Calculation of function volume Efficient capacity × × STEP2 Calculation of unit monetary value Unit annual monetary value of flood prevention function of paddy fields Annual amount of depreciation cost per unit efficient storage capacity of reservoirs (USD/m3/year) Monetary Assessment of the Multifunctional Roles of Paddy Fields

13. b) Groundwater Recharge function 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 STEP1 Calculation of function volume The groundwater recharge volume × × STEP2 Calculation of unit monetary value Water rate (USD/m3) (price of domestic water) Unit substitution cost Monetary Assessment of the Multifunctional Roles of Paddy Fields

14. c) Soil erosion prevention function 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 STEP1 Calculation of function volume Soil erosion volume prevented × × STEP2 Calculation of unit monetary value Unit labor cost to excavate soil eroded Labor cost (USD/m3) Monetary Assessment of the Multifunctional Roles of Paddy Fields

15. Yangon Jakarta Dhaka Bangkok Seoul Colombo Ha Noi Shanghai Kuala Lumpur Tokyo N.Y. Berlin London Roma San Francisco Note: Mean in 1971-2000 Source: WMO Monsoon and steep topography gives ample rainfall in the rainy season • The rainy season exists in monsoon Asia

16. Yangon Jakarta Dhaka Bangkok Seoul Colombo Ha Noi Shanghai Kuala Lumpur Tokyo N.Y. Berlin London Roma San Francisco Note: Mean in 1971-2000 Source: WMO Monsoon and steep topography gives ample rainfall in the rainy season • The rainy season exists in monsoon Asia

17. Precipitation (mm/year) 2000 1500 1000 500 (Average 1961-1990) 0 Actual Evapotranspiration (mm/year) 1000 750 500 250 (Average 1961-1990) 0 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 • 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

18. Monsoon Asia - Major production area of rice in the world Asia Source: FAOSTAT, Oxford Economic Atlas

19. Distribution of rice producing area Distribution of population density Importance of paddy rice production supporting massive population in monsoon Asia • About 54% of the world’s population survives in about 14% of the world’s terrestrial area Source: FAOSTAT, Oxford Economic Atlas Proportion 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

20. 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-1.Multi-purpose use of water by farmers B.Benefits gained by farmers and local community Aquaculture, duck raising, washing, cleaning, bathing, cooling, gardening, fire fighting, etc. B-2.Supporting local cultural-religious activities Diagram for categorizing multi-functionality

21. 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

22. A mechanism for enhancing governance and accumulating social capital Twin Spirals of Interaction between Governance and Social Capital Experience on Governance Accumulation of Social Capital B A Level of Social Capital Level of Governance cash technique cash time labor A B A： Spiral between governance on services for water distribution and social capital B： Spiral between governance on maintenances for infrastructure and social capital

23. Relation between amount of water reserved and ratio on reduced amount of agricultural water discharged from Makio reservoir in 1982/1994/2001 Water-saving ratio (%) • Change of ratio on reduced amount of agricultural water discharged from Makio reservoir in 1982/1994/2001 low high Shadow price of water highShadow price of water low Linear app. (1982) Linear app. (1994) Linear app. (2001) • Chart at the lower left provides negative correlation coefficients between amount of water reserved in Makio reservoir and water-saving ratio • Chart at the lower right shows that fluctuation of shadow price of water at source level • Temporary water transfer during abnormal dry spells brings enormous benefit to cities

24. Water-saving ratio for agricultural versus domestic use in discharge from Makio dam reservoir (1973-2002) Annually highest water-saving ratio (1973-2002) Water transferred from agricultural use to domestic use 1973 1974 1975 1976 1977 1978 1979 19801981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 Summer Winter water-saving ratio (%) About 800 days per 30 years Repeated temporary water transfer in Aich-yousui system Makio dam counts during 30 years (1973–2002) ; • 20 years when the discharged volume of water was restricted at a water-saving ratio • 16 years when the water-saving ratio for agriculture exceeded 20% • 15 years when agriculture granted water to domestic use during abnormal dry spells by setting a relatively higher water-saving ratio