assessment of water demand and supply under future climatic change conditions in the mae klong river...
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ASSESSMENT OF WATER DEMAND AND SUPPLYUNDER FUTURE CLIMATIC CHANGE CONDITIONS
IN THE MAE KLONG RIVER BASIN, THAILAND
Presented by
Chollada Rojrungtavee
Thesis Advisor: Dr. Mukand S. Babel
FoS: Water Engineering and Management
INTRODUCTION
Climate change impacts on water resources
• Hydrological uncertainties
• Uncertainties in water availability and demand
• Hydroelectric power production
• Water quality
• Habitats to living organisms
Objectives:
• To estimate the current and future water demand of the main water consumption sector in Mae KIong River Basin under climate change conditions
• To evaluate water balance situation and power production under climate change condition using reservoir operation
INTRODUCTION: Scopes of Study
Study Area• Mae Klong River Basin
Reservoirs• Srinagarind reservoir• Vajiralongkorn reservoir
Main Water Consumption Sector• Irrigation sector (GMKIP)• Inter-basin transfer sector• Salinity control sector
Years of Consideration• Base year 2005• Future years 2025, 2050 and 2095
Greater Mae Klong Irrigation Project
• Total area– 4,833.44 km2
• Provinces– Suphanburi– Nakornpathom– Karnchanaburi– Samutsakorn– Petchburi
Water Consumptions
Domestic Industrial IrrigationInter-basin transfer to Ta-Chin
Total
Water Requirement (MCM/year)
47.04 64.42 2,276.32 4,270.04 6,657.82
Percentage of Water Requirement
0.71 0.97 34.19 64.13 100
• Main water requirements• Irrigation• Inter-transfer to Ta-Chin River Basin
• Domestic and industrial together is less than 2%• Salinity control requirement at estuary
• 1,571 MCM/year
METHODOLOGY
Study Area Identification
Future Irrigation Water Requirements in the Greater Mae Klong Irrigation Project for 2025, 2050 and 2095
Future inflows into Vajiralongkorn and Srinagarind reservoirs for 2025,
2050 and 2095
Reservoir Operation Model(HEC-ResSim)
Future water balance situation in Mae Klong River Basin
Irrigation Water Requirement
Irrigation Requirement Estimation
Calculation of Reference Crop Evapotranspiration (ETo)
Calculation of Effective Rainfall
Upland Crops
USDA Soil Conservative Service Method
For Ptot < 250 mm:Peff = Ptot (125 – 0.2 Ptot)/125
For Ptot > 250 mm:Peff = 125 + 0.1 Ptot
Lowland Paddy Rice
Soil-Water Balance Method
Penman-Monteith Method
)34.01(
)(273
900)(48.0
2
2
u
eeuT
GRET
asn
o
• The estimation of irrigation water requirements is separated into two methods for upland crops and lowland paddy
Inputs: Maximum and minimum temperature, relative humidity, sunshine hours and windspeed
Irrigation Water Requirement
Upland Crops
Calculation of Reference Crop Evapotranspiration (ETo)
Calculation of Actual Crop Evapotranspiration (ETc)
Calculation of Effective Rainfall
Calculation of Irrigation Requirement
Penman-Monteith Method
ETcrop = Kc . ETo
USDA Soil Conservative Service Method
IRReq = ETcrop - Peff
Irrigation Water Requirement
Lowland Paddy
Irrigation Requirement
IR = U + LP + WL + P – ER + S2 – S1
Where IR = irrigation requirement
U = crop water requirement
LP = land preparation
WL = normal water level
P = percolation
ER = effective rainfall
S1, S2 = storages
Irrigation Water RequirementData Requirement
Comparison of Average Monthly Rainfall over the Great Mae Klong Irrigation Area
0
100
200
300
400
500
600
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Ave
rag
e M
on
thly
R
ain
fall
(m
m)
2005_ECHAM4A2 2025_ECHAM4A2 2050_ECHAM4A2
2005_OBS 2095_ECHAM4A2
Rainfall
Irrigation Water RequirementData Requirement
Paddy_wet44.2%
Sugarcane22.7%
Sweet corn2.6%
Maize6.8%
Green bean0.4%
Mango23.4%
Paddy_dry61.3%
Sugarcane5.1%
Sweet corn13.3%
Maize0.5%
Asparagus7.7%
Green bean12.1%
Wet Season Crops• Paddy = 1170.3 km2
• Sugarcane = 600.5 km2
• Sweet corn = 67.7 km2
• Maize = 179.4 km2
• Green bean = 11.7 km2
• Mango = 618.6 km2
Dry Season Crops• Paddy = 1208.7 km2
• Sugarcane = 100.3 km2
• Sweet corn = 263.3 km2
• Maize = 9.1 km2
• Green bean = 239.5 km2
• Asparagus = 151.9 km2
Cropping area
Irrigation Water RequirementData Requirement
Cropping Pattern
Reservoir Operation Simulation
Vajiralongkorn dam Srinagarind dam
GMKIP
Inter-basin transfer to Ta-Chin River Basin
Salinity control
Gulf of Thailand
Figure 3.5 Configuration diagram for simulation of Mae Klong river basin – minor demand tributaries not included
Required inputs for the simulation:
• Inflows into reservoirs
• Reservoir characteristics
• Operation rule curves
• Basin water demand
Reservoir Operation SimulationData Requirement
Inflows into the reservoirs
Comparison of estimated and predicted inflows into Srinagarind reservoir
0200400600800
1000120014001600180020002200
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Vo
lum
e (M
CM
)
SN_estimated2005 SN_predicted2025
SN_predicted2050 SN_predicted2095
Comparison of estimated and predicted inflows into Vajiralongkorn reservoir
0200400600800
1000120014001600180020002200
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Vo
lum
e (M
CM
)
VJK_estimated2005 VJK_predicted2025
VJK_predicted2050 VJK_predicted2095
Wet Dry Wet Dry Wet Dry Wet Dry
Volume (MCM) 3728 996 3583 1290 3605 1459 4074 1500Relative Change (%) -3.89 29.52 -3.30 46.49 9.28 50.60
Volume (MCM) 5057 413 4587 382 4799 484 4924 469Relative Change (%) -9.29 -7.51 -5.10 17.19 -2.63 13.56
2095205020252005
Srinagarind Dam
Vajiralongkorn Dam
Scenarios
Reservoir Operation SimulationData Requirement
Highest water level 180 m MSL
Lowest water level 159 m MSL
Tail water 55.5 m MSL
Highest storage 17,745 MCM
Lowest Storage 10,265 MCM
Surface area 418.8 km2
Annual evaporation 351.1 MCM
Power Plant
Installed capacity 360 MW
Spillway
Type Chute
Crest elevation 171 m MSL
Control gates 3 radial gates
Capacity 2,420 m3/s
Highest water level 155 m MSL
Lowest water level 135 m MSL
Tail water 87 m MSL
Highest storage 8,860 MCM
Lowest Storage 3,012 MCM
Surface area 388 km2
Annual evaporation 210 MCM
Power Plant
Installed capacity 300 MW
Spillway
Type Chute
Crest elevation 146 m MSL
Control gates 2 radial gates
Capacity 3,200 m3/s
Reservoir Characteristics
Srinagarind Reservoir Vajiralongkorn Reservoir
Reservoir Operation SimulationData Requirement
Water Levels of Srinagarind Reservoir
155
160
165
170
175
180
185
Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08
Month
Ele
vati
on
(m
. M
SL
)
Water Level Upper Rule Curve Low er Rule Curve Flood Control Curve Minimum Water Level
Existing Rule Curves and Water Level – Srinagarind Reservoir
Reservoir Operation SimulationData Requirement
Existing Rule Curves and Water Level – Vajiralongkorn Reservoir
Water Levels of Vajiralongkorn Reservoir
130
135
140
145
150
155
160
Jan-98 Jan-99 Jan-00 Jan-01 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08
Month
Ele
vati
on
(m
. MS
L)
Water Level Upper Rule Curve Low er Rule Curve Flood Control Curve Minimum Water Level
RESULTS AND DISCUSSIONIrrigation Requirements
Monthly Crop Irrigation Requirement_Upland Crops Only
0
100
200
300
400
500
600
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Cro
p Ir
rig
atio
n R
equ
irem
ent
(mm
)
Yr2005
Yr2025
Yr2050
Yr2095
Monthly Crop Irrigation Requirement_Paddy Only
0
50
100
150
200
250
300
350
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Cro
p Ir
rig
atio
n R
equ
irem
ent
(mm
)
Yr2005
Yr2025
Yr2050
Yr2095
Upland Crops
Lowland Paddy
RESULTS AND DISCUSSIONIrrigation Requirements
Monthly Crop Irrigation Requirement_TOTAL
0.00
100.00
200.00
300.00
400.00
500.00
600.00
700.00
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Cro
p Ir
rig
atio
n R
equ
irem
ent
(mm
)
Yr2005
Yr2025
Yr2050
Yr2095
2005 2025 2050 2095
Wet Dry Wet Dry Wet Dry Wet Dry
Volume (MCM) 637.48 1597.60 235.97 1739.82 302.94 1721.72 82.94 1814.85
Total 2235.08 1975.78 2024.66 1897.80
Relative change (%) -62.98 8.90 -52.48 7.769 -86.99 13.60
Total Irrigation Requirement
RESULTS AND DISCUSSIONWater Balance Situation
Control Points Available at CP Shortage at CP
Wet Dry Wet Dry
VJK 7182.29 335.92 0.00 0.00
SNR 5893.38 788.88 0.00 0.00
GMKIP 8339.69 5110.97 30.21 85.89
DIV to Ta-Chin 7067.24 1989.22 0.00 0.00
Salinity Control 6571.18 1596.34 125.28 212.44
Total 155.49 298.33
Control Points Available at CP Shortage at CP
Wet Dry Wet Dry
VJK 5467.98 385.31 0.00 0.00
SNR 4992.02 1436.55 0.00 0.00
GMKIP 5319.60 5591.04 0.01 23.41
DIV to Ta-Chin 4840.03 2204.15 0.00 0.00
Salinity Control 4282.82 1784.94 105.59 141.02
Total 105.60 164.43
Control Points Available at CP Shortage at CP
Wet Dry Wet Dry
VJK 6144.27 332.64 0.00 0.00
SNR 5188.08 858.62 0.00 0.00
GMKIP 5447.91 5417.17 0.05 7.68
DIV to Ta-Chin 4828.62 1973.80 0.00 0.00
Salinity Control 4289.92 1520.11 97.20 132.38
Total 97.25 140.06
Control Points Available at CP Shortage at CP
Wet Dry Wet Dry
VJK 6082.53 581.48 0.00 0.00
SNR 5853.01 1550.27 0.00 0.00
GMKIP 7211.38 5795.71 0.00 52.58
DIV to Ta-Chin 7037.53 2208.76 0.00 0.00
Salinity Control 6478.27 1757.59 12.01 97.47
Total 12.01 150.05
Year 2005 Year 2025
Year 2050 Year 2095
RESULTS AND DISCUSSIONWater Balance Situation
Monthly inflow and release_Sringarind dam
0
200
400
600
800
1000
1200
1400
1600
1800
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Vo
lum
e (M
CM
)
Inf low
Release
Monthly inflow and release_Vajiralongkorn dam
0
500
1000
1500
2000
2500
3000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
MonthV
olu
me
(MC
M)
Inflow
Release
Year 2005 • Inflow and release
RESULTS AND DISCUSSIONWater Balance Situation
Water availability, supply and requirement at Irrigation CP_2005
0
200
400
600
800
1000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Vo
lum
e (M
CM
)
Supply at CP Requirement at CP
Water availability, supply and requirement at Inter-transfer CP_2005
020406080
100120140160
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Vo
lum
e (M
CM
)
Supply at CP Requirement at CP
Year 2005 • Water supply and requirement at each control point
Water availability, supply and requirement at salinity control CP_2005
020406080
100120140160
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Vo
lum
e (M
CM
)
Supply at CP Requirement at CP
RESULTS AND DISCUSSIONHydroelectric Power Production
Power production of VJK
0
1000
2000
3000
4000
5000
6000
7000
8000
January-02 January-03 January-04 January-05 January-06 January-07 January-08
Month
Po
wer
(M
Wh
)
Pow er_act
Pow er_sim
2005_act 2005_sim 2025_sim 2050_sim 2095_simPower (MWh) 17878.38 16931.81 19200.26 28023.38 22335.88Relative Change (%) - - 13.40 65.51 31.92
Total Power Production (MWh)
Vajiralongkorn Reservoir
CONCLUSIONS AND RECOMMENDATIONS
• CONCLUSIONS• Rainfall tends to increase in large amount in wet season, but dry season
rainfall remains more or less similar to the present amount.• With climate change condition, the total irrigation requirements in Greater Mae
Klong Irrigation Project decrease significantly during the wet season and some increment during the dry season
• Large amount of water is available within the basin, but still small shortages occur for the dry season irrigation requirement and at the salinity control point
• RECOMMENDATIONS• Proper water management measures should be proposed to allocate enough
amount of water to each water demand points to avoid shortages• Further studies on estimating the impacts of climate change on inter-basin
transfer and salinity control demands could be done and included in the reservoir operation
• Land use and irrigation area changes could be considered for the future development in the basin
• Operation rule curves could be considered for the changes over the next 100 years
THANK YOU