Long-Term River Basin Planning:

GA-LP Approach Daene McKinney

Center for Research in Water Resources

University of Texas at Austin

Ximing CaiInternational Food Policy Research Institute

Leon LasdonDepartment of Management Science

University of Texas at Austin

Outline

• Sustainability in River Basin Planning

• Modeling Framework

• Solution Approach (GA-LP)

• Application

• Conclusions & Next steps

Sustainability in River Basin Planning

• Concepts of sustainable development – Demand management, supply reliability

and flexibility, environmental impact control, technology adaptation, economic efficiency, etc

• Broad guidelines – Provide guidance to planners, but– Not translated into operational concepts

that can be applied to specific systems

Modeling Framework

• Incorporate quantified sustainability criteria into long-term water resource systems models– Relations between water uses and their

long-term consequences – Tradeoffs in benefits received over many

generations

Application

• Water resources management in river basins with (semi) arid climate– Large diversions to irrigated agriculture– Potential for environmental degradation from water

and soil salinity

• Sustainability (one might define it as)– Ensuring long-term, stable and flexible water

supply capacity – Meeting irrigation and growing M&I demands, – Mitigating negative environmental consequences

Modeling Framework• Basic Premise

– Short-term decisions should be controlled by long-term sustainability criteria

• Long-term (Multi-year) Control– Inter-Year Control Program (IYCP) – Long-term model controlling short-term decisions

to approach sustainability

• Short-term (Annual) Control– Sequencing of Yearly Models (YMs) – Short-term models optimizing benefits for a year

Modeling FrameworkInter-Year Control Program (IYCP)

Inter-Year Control Variables (IYCV)

ws End of year water storageA Available area of a crop1 Water distribution efficiency 2 Water application efficiency 3 Water drainage efficiencytax Salt discharge tax rate

Yearly models

YM 1 YM 2 YM Y

Sustainability Criteria

RELi Reliability criterion, i = a or eREVi Reversibility criterion, i = a or eVULi Vulnerability criterion, i = a or e ENV Environment criterion SEQ Spatial equity criterionTEQ Temporal equity criterionEA Economic acceptability criterionEach is

NLP or LP

Solve by GA

Demand site (d)Area (a)Field (f)

WAF2

G

Q1

DP

ETA

DD

Groundwater

Crop (c)

WA

R

ER

RF P

Yearly Model

ObjectiveIrrigation benefitHydropower benefitEnvironmental benefit

ConstraintsFlow balancesSalinity balancesPolicy constraints

Solving the Yearly Model

IYCP

IYCP

IYCV(y) IYCV(y+1)

solution foryear y

solution foryear y+1

Stored water

Water salinity, Soil salinity,

Salt discharge

Flows

YM(y) YM(y+1)

FM(y) FM(y+1)

SM(y) SM(y+1)Water salinity,

Soil salinity, Salt discharge

Soil salinity, Salt discharge

Stored water

YM FM + SMDecomposeLinearizeLPs for each year

IYCP Objective Function • Weighted sum of sustainability criteria:

– Risk criteria (expressed in terms of agricultural and ecological water use)

• Reliability (frequency of system failure)

• Reversibility (time to return from system failure) • Vulnerability (severity of system failure)

– Environmental criteria • Max allowable water and soil salinities

– Equity criteria • Temporal (equitable access to benefits over time)

• Spatial (equitable geographic access to water)

– Economic acceptability criteria (impact of investment benefits)

Yeary=1,…,Y

Performance for year y

Performance of individual i:

F(IYCVg,i)=F(Risk, Env, Equity, Econ)

Performance of generation g:

Fi = F(IYCVg,i) , i=1,…,I

Individuali=1,…,I

Generationg=1,…,G

YM(y)

Igiggg IYCVIYCVIYCVIYCV ,,1, ,,,,

Yig

yigigig IYCVIYCVIYCVIYCV ,,

1,, ,,,,

ig

yd

ycd

yd

ycd

yd

yyig TAXAwsIYCV

,,,, ,,3,2,1,

Inter-Year Control Variables (IYCV)

ws Water storageA Area for crop1 Distribution efficiency 2 Application efficiency 3 Drainage efficiencytax Salt discharge tax rate

Solving the IYCP

IYCP

IYCV

YMs

Sustainability Criteria

IYCP

IYCV

YMs

Sustainability Criteria

IYCP

IYCVIYCV

YMs

Sustainability Criteria

Sustainability Criteria

Application – Syr Darya Basin

Syr Darya

Amu Darya

0

10

20

30

40

50

60

70

80

1930 1940 1950 1960 1970 1980 1990 2000

Flow

(km3), Level (m), Area

(103 km2)

0

1

2

3

4

5

6

7

8

Irrigated Land

(106 ha)

Flow

Area

Level

Irrigated Land

Aral Sea Basin XX Cent.

Aral Sea Basin (1989 – 2000)

0

10

20

30

40

50

60

70

80

90

100

110

120

130

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

Ru

no

ff a

nd

In

flo

w (

km3)

Basin Runoff

Aral Inflow

•Question: Can irrigated agriculture be sustained while minimizing environmental impacts?

Amount being used for Irrigation

ASB River System

PovodhashCanal

Karadarya R.AndijanRes.Side

Inflow

AndijanUse

SideInflow

Naryn R.Toktogul

Res.

KurpsaiRes.

TashkamurRes.

ShamaldysaiRes.

UchkurganRes.

Side Inflow

Toktogul-Uchkurgan Use

AdjarUse

KayrakumUse

KayrakumRes.

CharvakRes.

Charvak R.

UgamInflow Side

Inflow

ChirchikUse

SideInflow

Kayrakum-Chardara Use

Arnasai

Kyzlkum Canal

SideInflow

Chardara-Aral Sea Use

Aral Sea

Vahsh R.

NurekRes.

Pyandj R.

Kafirnigan R.

Kashka R.

Surhan R.Upper Amu

Use

BukharaCanal

KarshiCanal

KarakumCanal

TuyamuyunRes.

RightCanal

Dashauz

LeftCanalDrinking

Canal

Petniak-Tash-Urgench

Klichbaj-Kipchak-Gumabaj

Soviet-Oktjabra-Pahta

KizketkenCanal

LeninaCanal

PumpingIntake

SYR DARYA BASIN

AMU DARYA BASIN

Small River or Side Inflow

Main River Inflow

Run-of-the-river Reservoir

Storage Reservoir

Hydropower Plant (HPP)

Diversion to User

User

PovodhashCanal

Karadarya R.AndijanRes.Side

Inflow

AndijanUse

SideInflow

Naryn R.Toktogul

Res.

KurpsaiRes.

TashkamurRes.

ShamaldysaiRes.

UchkurganRes.

Side Inflow

Toktogul-Uchkurgan Use

AdjarUse

KayrakumUse

KayrakumRes.

CharvakRes.

Charvak R.

UgamInflow Side

Inflow

ChirchikUse

SideInflow

Kayrakum-Chardara Use

Arnasai

Kyzlkum Canal

SideInflow

Chardara-Aral Sea Use

Aral Sea

Vahsh R.

NurekRes.

Pyandj R.

Kafirnigan R.

Kashka R.

Surhan R.Upper Amu

Use

BukharaCanal

KarshiCanal

KarakumCanal

TuyamuyunRes.

RightCanal

Dashauz

LeftCanalDrinking

Canal

Petniak-Tash-Urgench

Klichbaj-Kipchak-Gumabaj

Soviet-Oktjabra-Pahta

KizketkenCanal

LeninaCanal

PumpingIntake

SYR DARYA BASIN

AMU DARYA BASIN

Small River or Side Inflow

Main River Inflow

Run-of-the-river Reservoir

Storage Reservoir

Hydropower Plant (HPP)

Diversion to User

User

Small River or Side Inflow

Main River Inflow

Run-of-the-river Reservoir

Storage Reservoir

Hydropower Plant (HPP)

Diversion to User

User

Irrigation Profit

0

0.5

1

1.5

2

2.5

3

3.5

4

n n w vw vd d n n n n n w n w d n w n n vd n d d d w n n n d d

Irri

ga

tio

n b

en

efi

t (b

ln U

S$

) Master

Baseline

Scenarios•Baseline: No change•Master: Area & efficiencies are DV’s•Low Irrigation: reduced area

Crop Areas(Master Scenario)

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

Baseline Year 1-10 Year 11-20 Year 21-30

Irri

gat

ed A

rea

(%)

Cotton

Wheat

Alfalfa

Other

Efficiencies(Master Scenario)

Application Efficiency

0.5

0.55

0.6

0.65

0.7

0.75

0.8

Baseline 6-10 11-15 16-20 21-25 26-30

Ap

pli

ca

tio

n E

ffic

ien

cy

(%

)

0.5

0.55

0.6

0.65

0.7

0.75

0.8

Baseline 6-10 11-15 16-20 21-25 26-30

Dis

trib

uti

on

Eff

icie

nc

y (

%)

Downstream

Midstream

Upstream

Distribution Efficiency

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

n n w vw vd d n n n n n w n w d n w n n vd n d d d w n n n d d

So

il S

ali

nit

y (

dS

/m)

Baseline

Low Irrigation

SoilSalinity

Salt

0

5

10

15

20

25

30

35

40

45

50

n n w vw vd d n n n n n w n w d n w n n vd n d d d w n n n d d

Sa

lt d

isc

ha

rge

(th

ou

s t

on

ne

s)

Low Irrigation

SaltDischarge

Sustainability Criteria

Scenario REL REV VUL ENV TEQ SEQ EA

Baseline 4 4 4 3 3 3 NA

Master 2 2 1 2 2 1 1

Low Irrigation 1 1 2 1 1 2 2

High Irrigation 3 3 3 4 4 4 3

Sustainability criteria

Conclusions

• Modeling framework developed – short-term decisions combined with long-term

decisions to find sustainable patterns in irrigation-dominated river basins

• Results – Both soil and water salinity sensitive to changes in

irrigated area over the long-term– Small increases in irrigated area without

accompanying infrastructure improvements places the environment at risk

Conclusions

• Next Steps– Linking water and salt to energy– WB GEF project has incorporated

sustainability criteria into their project and are beginning to use the models

– Agricultural policy in the region– Both basins together (linked by energy)– Water allocation agreements

CAR Energy System

X – SmallH – ThermalG – HydroA – UserO – Pool

Amu Darya

Syr Darya

CAEP

Tajikistan

Turkmenistan

UzbekistanKazakhstan

Kyrgyzstan

X1

H1 G1

G2

H2

X2

X3

H3G3

X4H4G4

X5 H5G5

A1

A2

A3

A4

A5

O1 O2

O3

O4O5

Water Results Display

Energy Results Display