1. WATER RESOURCES ALLOCATION AND CONFLICTS: The case of the Euphrates and the Tigris Mehmet Kucukmehmetoglu Gebze Institute of Technology Turkey Jean Michel Guldmann The Ohio State University U.S.A.

2. INTRODUCTION History: Conflicts over the control of fertile and irrigable agricultural lands. Today: Conflicts over the control of scarce water resources. The Southeast Anatolia Development Project (GAP). Ethnicity & Religion: Turks, Arabs, Kurds, Sunnis, and Shiites. High population growth rates: Doubling over 20 years. Inelastic water supply.

3. LITERATURE REVIEW Applications of Cooperative Games Dinar & Wolf (1994) – Introduction of an international WM (Water Market) – Utilization of game theory and optimization – Incorporation of political feasibility analyses Rogers (1969) – The Ganges – Game theory (non-zero sum games) Rogers (1993) – ‘Reasonable and Equitable’ sharing – Pareto-Admissibility – Game theory

4. Application of Spatial Equilibrium Models to Water Allocation Problems Flinn & Guise (1970) First application of spatial price equilibrium model Hypothetical river basin and water allocation Vaux & Howitt (1984) Average cost pricing v.s. marginal cost pricing Water Market in California Results 1) Reduces the need for large supply-augmenting conveyance facilities 2) Provides welfare gains Booker & Young (1994) Colorado River Institutional Model (CRIM) Water market for efficiency

5. The Euphrates and Tigris River Basin Model (ETRBM) Goal: Development of a methodology and its application Content: Benchmark Model Application of cooperative game theory concepts to define sustainable benefits and water resources allocations

6. Model Assumptions Same agricultural productivity throughout the region; Environmental problems are ignored (e.g., salinization, low BOD); Same energy prices throughout the region; Water unit values in urban and agricultural areas do not vary throughout the region; In Iraq and Syria, only cities exceeding 100,000 are incorporated; Groundwater resources are ignored due to lack of spatial information; Constant water transportation unit costs throughout the region; The optimization model maximizes the total net benefits, rather than the benefits of any country or of any sub-portion(s) of the basin; Supply-to-supply internodal link unit costs are assumed to be the same as agricultural transport unit costs between supply and demand nodes; Water withdrawals per acre and per person are constrained by upper limits, to prevent excessive withdrawals.

7. Spatial Structure of the ETRBM 45 Supply Nodes (j) Turkey has 15 supply nodes Syria has 7 supply nodes Iraq has 23 supply nodes 63 Demand Nodes (i) Turkey has total of 24 demand nodes Syria has 16 demand nodes Iraq has 23 demand nodes Three Interbasin Links All links from the Tigris to the Euphrates from j=21 to j=12: Turkey to Syria from j=28 to j=14: In Iraq from j=31 to j=16: In Iraq

8. Mathematical Structure of the ETRBM Optimization Technique: Linear Programming Objective function (Maximize) – Agricultural benefits – Urban benefits – Energy benefits – Delivery costs to urban and agricultural uses – Transshipment costs over the links Constraints (Subject to) – Node balance constraints – Feasibility constraints (Supply to Supply & Supply to Demand) – Minimum & maximum withdrawal constraints – Equalities

9. Objective Function Sets: i: demand nodes (1 to 63) j & l: supply nodes (1 to 45) agr: set of agricultural demand nodes urb: set of urban demand nodes

10. Constraints: Node Balance

11. Constraints

12. Data and Parameter Estimates Supply Data – Tributary Flows – Return Flows – Evaporation Demand Data – Agriculture & Urban Use VALAG & VALUR MINAGR & MAXAGR MINURB & MAXURB – Water Conveyance Cost and Energy Price Data Transportation Costs Energy

13. General Summary of the Benchmark Solution Energy benefits constitute nearly 50% of overall returns; Return flows make up almost 50% of the water input from tributaries, and are available for reuse; Total water withdrawal is very close to the total tributary flow input, whereas water released to the Gulf makes up to 35% of the total tributary inflow.

14. Net benefits of Turkey and Iraq are almost the same – Turkey obtains most of her benefits from energy generation (75%) – Iraq obtains hers from agriculture (90%) – Syria obtains 56% from water withdrawals and 44% from energy generation Energy generation potential at the upstream nodes Agricultural uses potential at the downstream nodes – Turkey has the lowest transport cost – Iraq the highest transport cost Total urban transportation costs constitute an insignificant share of the total transportation costs in the whole system and in each county Benefit Allocation by Country and Use

15. Water Resources Allocation by Country, Basin, and Use The highest withdrawal (61,934 Mm 3 ) in Iraq Iraq obtains its major benefits from agriculture water withdrawal Turkey (with nearly 2/3 of Iraqi land) withdraws only 1/6 of Iraqi withdrawal (10,263 Mm 3 ) Urban withdrawals (1,022 Mm 3 ) Agricultural withdrawal (77,505 Mm 3 ).

16. COOPERATION AND CONFLICT IN WATER RESOURCES ALLOCATION: Game – Theoretic Analyses

17. Objective Functions Individual Country Objectives Coalition Objectives Grand Coalition Objective (Equivalent of Objective in the Benchmark Model)

18. Core Conditions

19. Models for Core and Subsidy Determination Maximize Subject to

20. Shapley Allocation (e.g., Iraq) Iraq joining the “empty” coalition Iraq joining either the Turkey or Syria coalition Iraq joining the Turkey-Syria coalition

21. Core Analysis Summary

22. Differences Between Shapley, Core, and Minimum Benefits

23. FURTHER RESEARCH Environmental issues – Gulf area preservation (intrusion), salinization, drainage Utilization of nonlinear objective functions Incorporation of groundwater resources Multi-period river basin analyses – Utilization of large reservoirs More details for the demand nodes (smaller size) Projections for the future demands Water transfers to the other countries – From where to where? – Impacts to the system Evaluation of impacts of important projects and government subsidies – e.g., Urfa Tunnel