Water allocation optimization in the Orontes River Basin

Georges Comair and Raquel Flinker

Outline

Description of the setting

UN Convention and Factors Associated with Equitable Water Use

Optimization function

Optimal allocation results

The Orontes River Basin

Factors Associated with Equitable Water Use

1. Geography 2. Hydrology 3. Climate 4. Past utilization of the waters 5. Economic and social needs6. Population dependent on the waters 7. Comparative costs of alternative means of satisfying

the economic and social needs of each basin state8. Availability of other water resources9. Degree to which the needs of a basin state may be

satisfied, without causing appreciable harm and substantial injury to a co-basin state.

Factor 1: Geography

Countries Catchment area

(km2)

Lebanon 2,208.73

Syria 16,979.18

Turkey 5,556.56

Total 24,744.48

Turkey22%

Lebanon9%Syria

69%

Factor 2: Hydrology

11%

44%

45%

Contribution to annual discharge

Lebanon Syria Turkey

Factor 3: Climate

Turkey Lebanon Syria

662

560

463

Precipitation

mm

35.3%

23.5%

41.2%

Climate

Syria Lebanon

Factor 4: Existing Utilization

89%

11%

Factor 5: Economic and Social Needs Water demand that meets Economic and social

needs.

Syria does not use its water resources very efficiently

CountriesCurrent Water Demand (million m3)

Lebanon 80

Syria 2,687

Turkey 500

Total 3,26782.2%

2.4%

15.3%

Economic and Social Needs

Syria - FAOLebanon - GovernmentTurkey - Es-timate

Factor 6: Population Dependent on Waters

63.1%36.9%

Population De-pendant on Wa-

tersSyriaLebanonTurkey

CountriesPopulation Dependant on Waters

Lebanon 0

Syria

2,528,000

Turkey

1,480,571

Total

4,008,571

Factor 7: Comparative Costs of Alternatives

CountriesGDP (million US$) World Bank 2010

Lebanon 39,006

Syria 59,147

Turkey 734,364

Total 832,517

7.1%

4.7%

88.2%

Comparative Costs of Alternative

SyriaLebanonTurkey

Factor 8: Availability of Other Resources

Water Stress Index

Syria Turkey Lebanon0

10

20

30

40

50

6054

2620

0

20000

40000

60000

80000

100000

120000

Total water demand in each coun-try

Total re-newable wa-ter re-sources

Factor 9: Appreciable Harm

82.2%

2.4%

15.3%Economic and Social

Needs

SyriaLebanonTurkey

Can be measured by impacts on social, economic and environmental needs.

Class Survey

1. Geography

2. Hydrology

3. Climate

4. Existing utilization

5. Economic and social needs (water demand)

6. Population dependent on waters of the basin

7. Comparative costs of alternative (GDP)

8. Availability of other resources (Water Stress Index)

9. Appreciable harm

Geogr

aphy

Hydro

logy

Rainf

all

Exist

ing

utiliza

tion

Wat

er d

eman

d

Popu

latio

nGDP

WSI

Appr

eciable

harm

0

5

10

15

20

25

6

108 9

15 14

9

15 14

8

15 14

20

1210

8 85

Factor Weights (%)

Class AcademiaExperts

Optimization

Minimize E = 2

Xij is the share of the ith factor for the jth country (%)

Aj is the proportion of the total water that each country should receive (%)

Wi (%) is the weight to be given to each factor taken from the class survey

Existence of Solutions Weierstrass Theorem

Describes conditions on the objective function and the constraint set so that we are guaranteed that solutions will always exist Constraint set is compact (closed and bounded) Objective function is continuous on the constraint set

Optimization results

58%23%

19%

Results - Class

Syria TurkeyLebanon

55%25%

20%

Results – Water Experts

Syria TurkeyLebanon

83%

10%7%

Agreement

Syria TurkeyLebanon

Questions

1. What additional factors do you think should be included in this analysis?

2. Do you agree with the assumptions made for each factor?