The project delivery specialists Modelling of Sedawgyi Irrigation Network with RIBASIM Internship assignment Sebastiaan Quirijns 1.

The project delivery specialists

Modelling of Sedawgyi Irrigation Network with RIBASIMInternship assignment Sebastiaan Quirijns

1

Welcome

Thank you all for contributing to my study,

by sharing all of your resources

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Contents

• Introductions• Goal of project• Scope of project

• RIBASIM Background• RIBASIM Requirements• Initial Analyses• Scenarios• Results• Conclusions and Recommendations• Q & A• End

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Scenarios- Base Case

- Do Nothing Case- ADB Reference Case

- Sustainable Urban Drainage System

- Irrigation Efficiency (CTA)- Secondary Open Channel

- Separation of Water Resources System

Introductions

• Introduction speaker:• Netherlands

• Delft• Technical University of Delft• Hydraulic Engineering• Graduating in July 2015• Internship for Peter Kerssens of

Haarlem Hydraulics

4

Introductions

Current issues of the Sedawgyi Irrigation Network• No clear distinction of the main function of the Sedawgyi dam• Too high shortage of water for irrigational purposes• Too much water which is spilled during rainy season

The main goal of the study is:

“Modelling of the water resources in the Mandalay Region in order to increase the water usage efficiency”

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Introductions

Scope of the study• Four natural boundary limits

• North Sedawgyi reservoir• East Shan Hills• South Dokhthawaddy• West Ayeyarwaddy

• RIBASIM applications• Modelling of water resources for rivers and basins

• Depth of study• Mandalay is simplified into two subjects

• Public Water Supply• Moat flow

• Sedawgyi Dam controls inflow into basin• No groundwater flow included in the model

6

Introductions

Four natural boundary limits• North Sedawgyi reservoir and

mountains• East Shan Hills• South Dokhthawaddy• West Ayeyarwaddy

7

RIBASIM Background

RIBASIM (RIver BAsin SImulation Model)• Generic model package for analysing the behaviour of river basins under

various hydrological conditions, developed by Deltares (the Netherlands)• Simulation of water allocation in a water resources model

• Main classification of the nodes are Demand, Control and Layout.• Time step size is daily, weekly, half monthly or monthly basis• Demand nodes determine flow in the links

• Basin performances• Water allocation• Water shortages• River basin water volumes • Flow composition• Crop production• Flood control• Water supply reliability• Etc.

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RIBASIM Background

Important aspects for

Agriculture in RIBASIM• irrigation water distribution• topography and lay-out of the irrigation

area• crop and soil characteristics• crop plan• expected and actual rainfall• reference evapotranspiration• agriculture practice• operation and irrigation water

management• actual field water balance• crop survival fraction• potential crop yield and production costs

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RIBASIM Background

Typical applications• long term basin planning - time horizon of 20 to 25 yrs.• short term water allocation - time horizon 0,5 to 1 yrs.

scheduling• In season operation - during the season based on the

scheduling actual situation in the field• flow forecasting system - any time at various locations

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RIBASIM Requirements

Primary data required for modelling with RIBASIM• Time series

• Rainfall• Five locations

• Dependable rainfall• Five locations

• Water balance of Sedawgyi reservoir• Inflow• Evaporation

• Reference evapotranspiration

• Fixed data• Catchment areas• Reservoir volume• Cultivated areas• Crop data

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Initial Analyses

Sedawgyi Irrigation Network Map• Sedawgyi Reservoir• Mandalay (±1,2 million

inhabitants in 2014) • Madaya (±30000 inhabitants in

2014)• Three rivers and/or canals

connected to Sedaw Weir• Mandalay Main canal• Yenatha canal• Chaungmagyi

• Many agriculture• Many distributaries

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Initial Analyses

Non Revenue Water

Mandalay 63%• Physical losses

• Leakages• Overflow

• Commercial losses• Under counting• Illegal connections• Unbilled consumption

Mandalay’s demand• 101 l/capita/day• 15 % supplied by surface water• 15 l/capita/day

Note: Mandalay does not get water from Sedawgyi Water Resources System. It is assumed this way, because of modelling’s sake.

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Saying in modelling

“Prove from the absurd”

Initial Analyses

Index DY’sLength [m]

Depth [m]

Q[m3/s]

Summer paddy [ha]

1Shwetha-Chaung 3810,0 1.0 56,6 5608,4

2 Thamok-So 10363,2 1,4 54,1 1827,6

3 Nandar 5852,2 1,1 34.0 1633,2

4 Alebon 6370,3 0,9 29,2 1594,4

5 Htanpingon 6446,5 0,9 22,4 1276,8

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• 5 Largest cultivated areas (of total 20) connected by distributaries (DY’s) to the Mandalay Main canal

Initial Analyses

Agriculture in Sedawgyi Irrigation Network

Crops Total Area [ha] percentageSummer Paddy 29883 64%Winter Paddy 29883 64%Sesame 593 1%Sunflower 0 0%Pulses 3236 7%Corn 2929 6%Ground nut 446 1%Garlic 0 0%Wheat 4059 9%Soybean 229 0%Banana 3655 8%Sugarcane 5279 11%Vegetables 286 1%Cattle 684 1%Total 46939 100%

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Initial Analyses

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• Primary canals• Mandalay Main

Canal• Yenatha• Chaungmagyi

• Secondary canals

• All DY’s

Initial Analyses

Climate Change effects

Forecasted changes at Mandalay (Dry Zone)• Slight increase of Annual Rainfall (10% in 2040)• More drought in the pre- and post-monsoon periods (May,

June & October: 35% lower rainfall)• Decrease in monsoon duration• Increase in intensity of rainfall (25%) during monsoon period

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Initial Analyses

Season Period Average temperature (°C)

Expected increase in temperature in 2020 (°C)

Average temperature in 2040 (°C)

Change in periods

Climate change factor for rainfall

Winter November to February

16 to 30 +1.2 +2.2October to februari

98.35%

Summer March to April 21.5 to 37 +1.0 +2March to June

98.35%

Monsoon May to October 25 to 34 +0.6 +1.6July to September

100.37%

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Climate Change effects

Initial Analyses

Sedawgyi Dam key values• Length of dam 1256 m• Top of dam 131,4 m• Max water level 130 m• Full Reservoir level 128 m• Dead capacity level 111 m• Catchment area 342500 ha• Hydropower cap. 25 MW

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Initial Analyses

Water spread/Capacity curve for the Sedawgyi Reservoir

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0.06.212.337.086.3103.6154.2283.7678.4

0.0 6.2 12.3 37.0 86.3 103.6 154.2 283.7 678.4

0.00

20.00

40.00

60.00

80.00

100.00

120.00

140.00

160.00

Reservoir Capacity

Waterspread

Reservoir capacity [ 106 m3]

Water level [m]

Water spread [ha]

Scenarios

The scenarios for long term modelling have to be included with some effects:• Long term effects

• Population growth of Mandalay to 2,3 million• Urbanization of Mandalay

• Increase in paved open areas• Madaya is connected to Sedawgyi Resources System• Climate Change

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Scenarios

Design Criteria

Hard design criteria Direct results, easily measurable • Reservoir volume• Reservoir spillage• Net flow in and out of reservoir• Generation of hydropower• Actual cultivation areas• Supply/demand ratios for cultivations• Irrigation efficiency• Supply/shortage for PWS• Continuous flow in the moat canal

Soft Design Criteria Indirect results, difficult to measure• Quality of life, food security, food diversification, environment, ‘Green cities’,

sustainable development, etc…

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Scenarios

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Base Case 2013-2014

Main function of the ‘Base Case’ is to visualize the current situation

Second function is for calibration of

the model

Scenarios

Do Nothing Case 2039-2040

Effects• long term effects are included

Main goal• visualize issues

Ideology• see what happens, autonomous

developments (population, urbanization, CC), but no corrective measures (yet)

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Scenarios

ADB Reference Case 2039-2040

Effects• Network Coverage is increased to 95% (2,2

million people)• Surface water dependency is increased to

47% (68 liter/capita/day)• NRW is reduced to 10%

Main goal• Increase welfare in Mandalay• Increasing demand of Mandalay• Reduce losses

Ideology• Since most of these plans have a large

probability of being executed. This case serves as reference case.

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Scenarios

Sustainable Urban Drainage Systems 2039-2040 (SUDS)

Effects• Increasing soil permeability→runoff via

groundwater → return flow to the surface water

• ADB reference plan

Main goal• Reduce flooding in the city• Beautification of Mandalay

Ideology• By achieving the main goals the ‘Qualitiy

of life’ will increase in Mandalay

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Scenarios

Irrigation Efficiency 2039-2040 (via Capacity Training Agriculture)

Effects• Increasing field irrigation Efficiency to 90%• ADB Reference Plan

Main goals• Increase yields/production• Save water• higher supply/demand ratios for

Agriculture

Ideology• If the efficiency of irrigation is increased,

by supplying new technology and training, this will lead to an high effective supply, and result in more water available for PWS purposes.

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Scenarios

Secondary Open Channel

2039-2040 (SOC)Effects• A collector drain is connected to Mandalay

Main Canal• Flood flow from Shan Hills is redirected and

redistributed in the Southern Irrigation Network System

• ADB Reference Plan

Main goals• Increase safety of Mandalay• More efficient use of flood flow

IdeologyIf the the water from the flood flow is redisitributed, this should lead to a lower demand to Sedawgyi in the southern area.

Thus an increase in supply in the northern area.

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Scenarios

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Catchment area: DetailedCatchment area: Simplified

Scenarios

Separation of Water Resources System 2039-2040 (SWRS)

Effects• Removing Mandalay Nodes for PWS and

Moat• ADB Reference Plan

Main goal• Increased water availability for irrigation

purposes and PWS of Madaya

Ideology• Mandalay’s water supply will come from

any other sources, except Sedawgyi Water Resource System

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Results

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1 4 7 10 13 16 19 22 25 28 31 34 37 40

-2.00E+02

-1.00E+02

0.00E+00

1.00E+02

2.00E+02

3.00E+02

4.00E+02

5.00E+02

6.00E+02

Calibration Sedawgyi Reservoir 2013-2014

Measured Data

Simulated Data

Difference

Timesteps [ts], 1 year = 24 ts

Rsv Volume [Mm3]

Results

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1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 390.00

2.00

4.00

6.00

8.00

10.00

12.00

Calibration Generated Hydropower

Measured

RIBASIM

Timesteps [ts] 24 ts= 1 year

Hydropower [GWh]

Results

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1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 490.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

450.00

500.00

Sedawgyi Reservoir Volume

BC

DNC

ADB

CTA

SOC

SWRS

Timesteps 1ts=half month

Volume [Mm3]

Results

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1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 490.00

50.00

100.00

150.00

200.00

250.00

300.00

350.00

400.00

Sedawgyi Reservoir Spilling per scenario

BC

DNC

ADB

SUDS

SOC

SWRS

Timesteps

Flow Spilled [m3/s]

Results

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0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48

-400.00

-300.00

-200.00

-100.00

0.00

100.00

200.00

300.00

400.00

500.00

Net flow Sedawgyi Reservoir

Base Case 2013-2014

DNC 2039-2040

ADB 2039-2040

SUDS 2039-2040

CTA 2039-2040

SOC 2039-2040

SWRS 2039-2040

Timesteps

Netflow [m3/s]

Results

36

0.00

3.00

6.00

9.00

12.0

015

.00

18.0

021

.00

24.0

027

.00

30.0

033

.00

36.0

039

.00

42.0

045

.00

48.0

00.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

Generated Hydropower

BC

DNC

ADB

SUDS

CTA

SOC

SWRS

Timesteps

Generated Hydropower [GWh]

Results

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NC_AIr_

Seikth

aDY

NC_ AIr_

Feede

rCut

DY

CW_A

Ir_Shw

eTaC

haun

gDY1

CW_A

Ir_Shw

eTaC

haun

gDY2

NC_Air_

LatK

aung

DY

NC_AIr_

Alebon

DY

NC_AIr_

Htanb

ingon

DY

NC_AIr_

Kabed

DY

NC_AIr_

Lund

aung

DY

SC_AIr_

Nanda

DY

SC_AIr_

Kyauk

than

batD

Y

SC_AIr_

Pathe

ingyiD

Y

SC_AIr_

Yankin

gtau

ngDY&Ye.

..

SE_AIr_

168M

inor

SC_AIr_

Wan

gingo

nDY

SC_Air_

Kyauk

MiD

Y

S_AIr_

Tadain

gShe

DY

S_AIr_

Tamok

soDY

S_AIr_

Kinbak

DY

NE_AIr_

DY1

N_AIr_

DY2

N_AIr_

DY3-4-

5

NW_A

Ir_DY6-

7

CE_AIr_

L1-L

160.00

1000.00

2000.00

3000.00

4000.00

5000.00

6000.00

7000.00Cultivated Areas Sedawgyi Irrigation Network

Total Planned AreaBase CaseDO Nothing CaseADB Reference CaseSUDS CaseCTA CaseSOC CaseSWRS Case

Distributaries

Area [ha]

Results

38

CE_AIr_

L1-L

16

NC_AIr_

Seikth

aDY

NC_ AIr_

Feede

rCut

Dy

SE_AIr_

168M

inor

S_AIr_

Tamok

soDY

S_AIr_

Tadain

gshe

DY

SC_Air_

Kyauk

MiD

Y

S_AIr_

Kinbak

DY

CW_D

iv_Shw

eTaC

haun

gDY2

SC_AIr_

Kyauk

ThanB

attD

Y

SC_AIr_

Pathe

ingyiD

Y

SC_AIr_

Nanda

DY

NC_AIr_

Lund

aung

DY

NC_AIr_

Kabed

DY

NC_AIr_

Htanb

ingon

DY

NC_AIr_

Alebon

DY

NC_Air_

LatK

aung

DY

CW_A

Ir_Shw

eTaC

haun

gDY

SC_AIr_

Yankin

gtau

ngDY&Yek

yiDY

SC_AIr_

Wan

gingo

nDY

NW_A

Ir_DY6-

7

N_AIr_

DY3-4-

5

NE_AIr_

DY1

N_AIr_

DY20%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100% Supply Demand ratios in Sedawgyi Irrigation Network

Base CaseDo Nothing CaseADB Reference caseSUDSCTASOC

Results

BC DNC ADB SUDS CTA SOC SWRS

Gross Supply [Mcm] 13437,7 42476,9 42073,7 42364,2 37967 43351,8 45665,7

Effective Supply [Mcm] 5662,1 13932,6 17765 17897,4 28943 18313,7 19321,3

Overall Irrigation efficiency 42,1 42,2 42,2 42,2 76,2 42,2 42,3

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• Irrigation Efficiency per scenario in 2013-2014 and 2039-2040

Results

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BC DNC ADB SUDS CTA SOC SWRS

Average Monthly supply 2013-2039

0.27371125 0.326463908333333

1.2229581625 1.22252697916667

1.35654595833333

1.21764873333333

0

Average Monthly short-age 2013-2039

0.05474225 0.155267820833333

0.6921655 0.692596666666667

0.558577708333333

0.697474958333333

0

Average Monthly supply 2014-2040

0.3147679375 0.341226641666667

1.2652659375 1.26415363333333

1.500329875 1.2652659375 0

Average Monthlyl Shortage 2014-2040

0.0136855625 0.1405050875 0.64985775 0.650970041666667

0.4147938 0.64985775 0

0.250.751.251.752.252.753.253.754.25

Average Monthly flow for supply and shortageMandalay

Flow [m3/s]

Results

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DNC ADB SUDS CTA SOC SWRS

Average Monthly supply 2039

0.0270061658333333

0.0270061658333333

0.0270061658333333

0.027006165 0.0270061658333333

0.027006165

Average Monthly Shortage 2039

0.0000000046566125

0.000000005587935

0.0000000046566125

0.00000013411044

0.0000000046566125

0.0000000046566125

Average Monthly Supply 2040

0.0270061658333333

0.0270061658333333

0.0270061658333333

0.0270061658333333

0.0270061658333333

0.0270061658333333

Average Monthly Shortage 2040

0.0000001117587

0.0000000046566125

0.0000000046566125

0.0000000046566125

0.0000000046566125

0.0000000046566125

0.01

0.03

0.05

Average Monthly flow supply and shortage Madaya

Yearly Supply & Shortage [m3/s]

Results

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Base Case DNC ADB SUDS CTA SOC SWRS

Average Monthly Supply 2013-2039

7.94733098333333

6.10068497 6.02503871166667

6.09462284625

6.41915845833333

6.02307430833333

0

Average Monthly Supply 2014-2040

9.58333325 6.00725438333333

5.94594887916667

6.00642379583333

7.05462455833333

5.9459489625

0

Average Monthly Shortage 2014-2040

0.416666746139542

3.99274555437981

4.05405114197288

3.99357615122479

2.94537541280621

4.0540510625

0

Average MonthlyShortage 2013-2039

2.05266899806976

3.89931499004262

3.97496128780621

3.9053771192093

3.58084153780621

3.97692570833333

0

2.50

7.50

12.50

17.50

22.50

Average Monthly Water Supply-Shortage Moat

Yearly Supply & Shortage [m3/s]

Conclusions & Recommendations

• The increased dependency of surface water from the Sedawgyi for PWS in Mandalay is very unlikely to occur in practical sense, since the Ayeyarwaddy and groundwater are the major sources for water supply. Nevertheless, the cases have been modelled this way, because it is always a good modelling incentive to prove from the absurd/extreme values in order to show the differences between the scenarios the best.

• The model shows clearly, given the current operational settings of the Sedawgyi dam, that in 2040 as a result of the expected population growth and increased urbanization, large water shortages. Solely the Sedawgyi Reservoir can not supply both, public water supply and irrigation, if no additional corrective measures are taken (do-nothing scenario)

• The effect of the water supply situation will be exacerbated by the expected climate change effects in 2040.

• Sustainable Urban Drainage Systems (SUDS) are strongly recommended to improve urban drainage and flood management in and around Mandalay city, but will have a relative small effect on the water resources /water supply conditions.

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Conclusions & Recommendations

• One of the most effective measures to improve the situation is to increase the irrigation efficiency, reducing losses in the system and ensuring that irrigation water will be delivered at the right moment and the right place.

• A collector drain at the Shan plateau foothills is strongly recommended as it will be effective to reduce the flooding problem in Mandalay city, but will not do much for the water supply situation.

• Separation of the Water Resources System of Mandalay and Sedawgyi is very effective for increasing the cultivation areas and ensuring the city water supply. These cultivations react correspondingly by having an acceptable supply demand ratio, if compared to the other cases.

• In some cases the North-Eastern parts of town (and people) get flooded due to reservoir releases from Sedawgyi dam. This generally happens without any warning, and in winter time when water levels are high already. Rescue service is provided by the government, but it would be better to provide flood early warning. Further emergency assistance is given by Red Cross and other NGOs.

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Conclusions & Recommendations

Final Conclusion

Given the current operational settings of the Sedawgyi Dam, it clearly shows that in 2040 Sedawgyi Reservoir could not support both Public Water Supply and irrigation systems. So the water resources systems of Mandalay and Sedawgyi Irrigation Network should be separated. Sedawgyi will supply the irrigation and Mandalay will be provided by surface water of the Ayeyarwaddy and Dokhthawaddy. The modelling results of this study support the choices made by ADB PPTA.

If the irrigation efficiency is increased (ie. In steps of 50% to 60% to ... to 90%) in the long term (20 to 25 yrs) high yields can be achieved, by investments in training, technology and resources. This will also include lower losses and spillages in the water resources systems.

The current allocation of the dam is not efficient, in a way that there is still a high shortage of water supply in the downstream area of the Sedawgyi. In the future the allocation of Sedawgyi Dam should be based upon a hydrological study and including the demands of all stakeholders.

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Questions and Answers

Any Questions??

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Final

Thank you for this amazing experience here in Myanmar