Water Resources, Floods and Agro-Environment in Monsoon Asia

Takao MASUMOTO, Ph.D.

National Institute for Rural Engineering (NIRE), NARO, Japan Outline 1) Water resources: “visualization” of water circulation ・Quantity side in basic process: Agricultural water use plays an important role. ・Agricultural water circulation = complicated 2) Agro-environmental problems tackled in water resources fields ・Causes: climate change (extremes), food crisis, energy shortage, catastrophic earthquake ・Solutions: how to cope with those problems through “Visualization?” 3) Proposals for future subjects in agro- environmental research 2 Background  Rice cultivation in paddies = Not only high productivity, but also sustainable and environmentally friendly economic activity (Ex: 7,000-year-old rice cultivation in China)  Share of Agricultural water use  70 % Domestic Use Transition of  Coexistence of Variety i) Distinct wet and dry water use seasons  [Large amount in the Industrial Use /year) ＦＡＯ vulnerability, Extremes 3 world ( ) (droughts and floods)] ii) Various types of paddy irrigation  Agriculture→Human use Water (km activities→Anthropo- Agricultural Use genic change 3 Complicated agricultural water use (Tone River Basin as an example)  Diversity of  Difficult to grasp water irrigation (Various resources under complicated types) water use  [Visualization  Dissimilarity of water circulation] between dry Yagisawa Dam ▲Ashio Akaya River Naramata River r areas (field crop) e r Amami- Aimata v Naramata Dam veKusaki Dam ▲ i i ▲ yama Dam R OomamaR H.W. Rainfall Station and humid (paddy e ▲Fujiwara n ● Takatsudose ● River Obs. Point o Fujiwara Dam a T Ohtar H.W. Dam ▲Katashina ta rice) areas Ouraa H.W. Head Works, W Diversion Weir Repeated use of Agatsuma ○ Intake Facility  Katashina River River Sonohara P Pump Intake Facility

Dam H i r e N . W . irrigated water Iwamoto ● ○ Hirose-momonoki ▲ Gunma Bando D.W. Sano Omoi River Tenguiwal a n Toneka Tonea D.W. Oura Watarase Reservior C Kitakawaberyo r Toneka P.S. Pi e sh v ●Yattajima a i Kabura River s ●Tone D.W. ●Kurihashi R ○ u o Nanmoku H.W. d M Minuma E Wakaizumi ● Tone D.W. Kasai Kanna H.W. Hanyu Shimanaka Shimokubo Dam Bizenkyo 4 Kanna River ▲Manba A Typical Irrigation Dominant Basin Seki-River Basin • Area：1,140km2, Length：64km

5 5 A Typical Irrigation Dominant Basin Diversion Weir Delivery channels

Sasagamine Reservoir Effective Storage : 9.2MCM

Paddy areas

6 6 Part １ Method and Approach for the Visualization (A) Hydrological Phenomena, (B) Anthropogenic (Human/ Artificial/ Agricultural) Activities

7 Mechanism of Agricultural Water Use (Observ. & Model Which Target Basin?)

 Paddy agriculture (global dissemination) 8  Monsoon Asia (East, South-East, South）, Australia, Europe [Italy, Spain, France etc.], USA [California St. etc.] Mekong River B.: A huge river basin in Monsoon Asia China, Myanmar, Laos, Thailand, Cambodia, and Vietnam (6 countries)  Area size (800,000 km2)  River length: 4,880km （the longest in S.–E. Asia)  Flooding in lower reach  Min/Max of dis.): 40～50 3 -1 3 -1 [1,800m s / 43,000m s ] 12  Paddies dominant (70%) MRB 9 Mekong River B.: A huge river basin in Monsoon Asia China, Myanmar, Laos, Thailand, Cambodia, and Vietnam (6 countries)  Area size (800,000 km2)  River length: 4,880km （the longest in S.–E. Asia)  Flooding in lower reach  Min/Max of dis.): 40～50 3 -1 3 -1 [1,800m s / 43,000m s ] 12  Paddies dominant (70%) MRB 10 Extremes in the Mekong

Record Flood in Year 2000 in the Mekong River Basin (An event of once in 30-60 years) 11 Components in Runoff and Water Allocation & Management System i) Basin-wide Runoff • DWCM-AgWU Model ii) Reservoir Management • To compare river discharge Snowfall/Snowmelt (available water) at division weir and water requirement Reservoir in irrigated paddies • To release water for Diversion Weir

irrigation Water Allocation River Flow Irrigated Paddies iii)Water Delivery in Irrigation Canal

Irrigated Paddies Root Zone •To decide intake, Unsaturated Zone water allocation, Saturated Zone infiltration, drainage 12 Calculation algorism of DWCM-AgWU (distributed water circulation model) Meteo. Geological & Celled Land Use Rainfall but Rainfall geomorphologic Basin Data Data Data Data Data

Estimation Model for Reference ET

Reference ET

Estimation Actual ET Model for Surface Runoff Paddy Water from the Estimation Upstream Mesh Model for Planting Use Time & Area, Planting Time Harvesting Area and Area Channel Flow Actual Intake, Calculation Soil moisture Paddy Storage Depth

Surface Runoff into Runoff Model the Downstream Mesh

Inflow into GroundwaterModel Flow for Reservoir GroundwaterRelease from the Dam into the Down- Flow from thethe Up -Dam 13 stream MeshOperation stream Mesh 13

Variability of agricultural water use modelled in the basin [Rain-fed paddy: 3 types] Using only rainfall Supplementary water use (small ponds) Using Flood water

14 14 Variability of agricultural water use modelled in the basin [Rain-fed paddy: 3 types] Using only rainfall Supplementary water use (small ponds) Using Flood water

15 15 Variability of [Irrigated paddy: agricultural water use 6 types] (0.1 degree中国 =10km cell) modelled in the basin China [Rain-fed paddy: 3 types]

Using only rainfall ラオス Using only rainfall Laos SupplementarySupplementary waterwater useuse (small(small ponds)ponds) Pakse TypeUsingUsing FloodFloodClassification waterwater Area (km2) Gravity irrigation (Weir) 11,870 タ Pump irrigation 3,580Thailandイ Irrigated Reservoir supply 6,030 Colmatage system 890 Tidal irrigation (Sluice) 1,830 Vietnamベトナム Tube-well (Ground water) 730 カンボジア Cambodia Rainfall 100,140

Rainfed Supplemental water use 42,920 16 Flooding water 6,830 16

Modeling of Release and Water Delivery System

Reservoir貯水池

Qresioutresiout

Qrsfrsf 河川 River /Channel Qrivriv 頭首工Head Work Qdivdiv 灌漑地区Irrigation Area

Qresiout : Release for Irrigation Qrsf : Runoff from Remaining Area Qriv : Discharge at the River Qdiv :Intake at Head Work, Qintake : (Qresiout + Qrsf) Delivery Water, Qrf :Return Flow, Qdiv : Intake at Head Work Qriv :River Discharge 17 Verification of DWCM-AgWU Model (i)Natur. runoff, ii)Dam manag., iii)Water allocat.)

400

100

200

18 Part ２ Agro-Environmental Problems Tackled in Water Resources Fields → “Visualization” did not abruptly occur, but it has been involved in social conditions (problems) 19 occasionally (5 applications). [Application 1]Climate Change Issue (Core tech.: Impact Assessment Method) Basic technology DWCM-AgWU Model Characteristics Able to carry out quantitative estimation at any time and space Able to estimate agricultural intake, planting/harvesting time/area, under various social scenario 20 Assessment on Extremes (Irrigation, Flood: “Itakura” Div. Weir Pt.)

1000 Used GCM: MIROC Itakura /s) 3 100 Discharge (m

1981−2000 2046−2065 13.9m3/s 2081−2100 1 1 2 3 4 5 6 7 8 9 10 11 12 Month

0 200 400 600 Apprehension not to intake enough water to “water right amount” in the future 21 Future change of irrigation water Ratio of irrigation water in the future compared to the present

（The rate of the end of the 21 C. [2081-2100] to the present [1981- 2000], (ex.: prediction during ） puddling periods 22 [Application 2] Overseas Assistance Problems in Agro-Environments  Basins for the application trials The whole Mekong River Basin Pursat River Basin (Cambodia) (Irrigation development in areas with scarce data) Nam Ngum River Basin (Lao PDR) (New water res. development for hydro-power) Xe Bang Fai River Basin (Lao PDR) (Annual flooding in paddies of the lower reaches) Mun-Chi River Basin (N.E. Thailand) (Irrigation by large- & medium-scale dams) Chao Phraya R.B.(Thai) (2011 flood & agri. water use

 All Monsoon Asia All over the world ? 23 Disordered Development due to the Lack of Fundamental Data i) Disordered plan

24 Disordered Development due to the Lack of Fundamental Data → ii) Break of embankments→ iii) Severe damage in the downstream

•Necessity of seamless simulat. for low-flows & floods •Proposal of ”Basin-wide Irrigat.” 25 Extraction of Experiments and Assessment Method Present： 1979～2003 Near Future： 2015～2039 End of 21stC.：2075～2099 Meteo. data Daily Precipitation Daily Max, Min, Ave. Temp. Humidity, Wind Speed (6-hour interval) Pressure to mean sea level (6-hour interval) Fig.:Calculation Extract the Mekong R. B. Area domain by from results of MRI-AGCM20 GCM20 0.1°Interpolation, Bias Brown dots: Correction GCM20 Calc. Simulation by the nodes Assessment Method 26 A New Approach for Generation of Long-term Continuous Data DWCM-AgWU→Generation of Quasi-Obs. Data

27 (ex.) Daily simulation for 25 years in the Pursat River B. [Application 3] Extension to Food Problems, Socio-Economical Assessm.  To all the basins of Japan, impact and scio- economic assessments on foods, agricultural water, irrigation facilities

Seki River Sea of Japan Basin

Hokura River Shogenji Dam Takada WL St. Itakura Div.Weir

Seki River Elevation (m) Sasa. Dam

Nojiri Lake （c) “Seki” River Basin

（a)1～5km Cell （b) All Japan accuracy (336 basins 28 in the whole Japan） Verification of estimated values for all over Japan 5000 2000

Blue: Observed /s) /s)

Ishikari R. 3 Abukuma R. 3 4000 Red: Estimated 3000 （）（） 2000 1000 1998 2000 Discharge (m Discharge (m 1000 0 0 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 400 3000 /s) /s) Kumano R. 3

Seki R. 3 300 （1997） 2000 （） 200 1999 1000 100 Discharge (m Discharge (m

0 0 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 3000 5000 /s) /s) Chikugo R. Tsurimi R. 3 3 4000 2000 （1997） 3000 （1998） 2000 1000 Discharge (m Discharge (m 1000

0 0 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12  Satisfactory results of the estimations  To be improved for Industrial and Domestic sewage in urban- dominant basins 29 Application of the Regional Water Allocation and Management Model Daily Estimation by 5km Cells

Planting of paddies (Area: %) River flows (m3/s) Start/Stop: determined by Discharges (flow in a cell cultivation day, irrigation center plus upstream inputs) amount, rainfall, soil estimated at arbitrary points moisture condition etc. and times 30 Food Security (Develop. of AFFRC Water-Food Model)  Convergence with Various Sectors (Agronomy,

Socio-economics) Food supply and Supply demand model Price

Impact analysis on Demand Foods in paddy- Production

dominant areas Yield Harvested area Socio- Proposal of counter- Economy Production Crop Production model measures [land use prediction model change (develop.), Hydrological / Growth data Meteorological breeding, irrigation, environment Topography water manag. etc.] and Hydrology and water use model land use Evaluation of effects （Regional water resources） WaterWater Water supply and of mitigation & requirementdemand water use Meteorological （Farmland water balance） data （original） adaptation methods Water management/watermanagement and distributionallocation in ‘Food Politics’ AFFRC Water-Food Model 31 Measurement of Risks by a Socio- Economic Model  A model to analyze impact factors in productivity（TFP)

-0.0277 ln(Total ln(Flood Dischar.) Productivity of AR(1) Parameters are the 0.1824 Rice) ln(Yield) results estimated as 0.0863 paneled data (9 regions ln(Quality) 0.0799 0.3285 ×32 years). Kunimitsu, etc. (in Print), Paddy ln(Accumul. R&D) ln(Economic Scale) and Water Environment  Monte-Carlo simulation by an Applied General Equilibrium Model (a prototype) Kunimitsu, etc. (2011) , WIT Press

32 [Application 4] Issues on Agricultural Water Right Negos among Ministries → Needs for ”Return-flow rate” estimation Difficult to observe those, but possible to estimate through a model (DWCM- Inflow Points Q AgWU Model) Div. Weirs irrig Searches for in/out-flow points • Search an irrigation area for outflow pts.(◯) Outflow and inflow pts.(◯) from Points residual areas Irrigated Area Estimation of outflow amounts • Estimate return flow rate in an irrigation area 33 Estimation Example for Seki River Basin

052.5k10 m

Kenshoji顕聖寺頭首工Div. Weir

Name of In- Out- Irrigation flow flow Area (Div. pts. pts. Weir) (●) (○) Itakura 33 21 子安頭首工 Koyasu Seki R. Div. Weir 25 8 Koyasu 11 5 Seki関川頭首工 River Kenshoji 23 7 D. W. Return還元地点 Flow Inflow流入地点 Pts Main関川主河道 River 板倉頭首工 Itakura Channels河道網 Diversion 34 Weir Estimated Results of River Return Flow Ratio

Average + σ Average (1976-2008) Average - σ Return Flow Rate Flow Return

Itakura Seki R. Koyasu Kenshoji Irrigation Area Annual change of Comparison of return return ratio ratio in irrigated areas  Return ratio is larger than expected. → Applicable to any river basin in Japan35 [Application 5] ISO in Water Resources (Water Footprint) Results of WF Inventory Analysis

Ratio of River Return Unit Processes, Irrigation Ratio Items ton/kg yield** Water to ([Return to Potential Rivers] Water /[Irrigated Availability Water])* (R + Qirrig) Rainfall (R) 1.649 Irrigation water 1.776 (4.593) (Qirrig) Inflows from residual (6.491) areas (Qres) 0.518 0.696 Returns into rivers (11.410) (0.735) (Qreturn) Infiltration 1.158 Evapotranspiration 0.946

• Average for 33 yｒｓ (1976– Leads to an application 2008) of daily calculations, of 【Visualization of 76.3-km2 irrigated areas Water Resources】 36 Part ３ Proposals for the Future Challenges in Agro-Environment Research

37 Challenging Research in the Future

 Mechanism →Climate and irrigation (the longer observation is, the more chances to discover new phenomena)  Notion of a basin →Change of the concept of basins (ex.: upland agric. on the Kashima Plateau, aqua-research)  Oversea assist. →Educational and technical assistance in Cambodia  Extreme events →2011 Flood in Thailand (Seam- less model of irrigation and flood) →Exports of socio-infras 38 Participatory disas. prev. →Practices for reducing floods by controlling irrigation gates 0 1000

10 500 20

0 0 1000

10 500 20

0 0 1000

10 500 20

0 0 6 12 18 24 [Proposal 2] Concept of the Basin Paradigm Shift of “Basin” (Boundary for Ground Water and Fishery Research) Under climate change, Future Earth: Realization of boundaries of surface water safe society, basin boundary and ground water, the same ? on the surface only ?

Change of rainfall patterns

Dam managem.

Prevention of soil erosion Flood storage in paddies

Stable flows Floods in rivers Small reservoir Supply into groundw Drought damage management Ag-drainage Inundation in low- lying ag-areas Return flow into rivers

Urban floods Usage for domestic water supply

Preservation of fresh water 40 [Proposal 3] Development of a Seamless Model for the Analysis of Extreme Events  Occurrence of 2011(2013, again) Chao Phraya River Flood → Seamless model for Irrigation & Flood → Export of a Rural Infrastructure (a package)

水田供給水量灌漑水田

管理用水量

水田からの流出灌漑水路河道へ流出

Snowfall/Snowmelt

Reservoir （Inte- Diversion Weir gra- Water Allocation River Flow Irrigated Paddies tion ) Irrigation Canal

Root Zone Unsaturated Zone

Saturated Zone Regional Drainage and DWCM-AgWU Model Inundation Model 41 Conclusion 1) To tackle with agro-environmental problems through “visualization” of water circulation 2) Methods: Obs. and modeling =[visualization] Backgrounds: Big issues against agro- environments have occurred one after another as food, CC, energy, massive earthquakes, etc. Do not live against the tides of the times! Contents: Application 1), 2), 3), ・・・ Proposal 1), 2), 3), ・・・・・ Seamless treatment in irrigation and flood! 42 The End Thank you for your attention.