TECHNO ECONOMIC AND MANAGEMENT (TEAM) APPROACH TO RIVER BASIN PLANNING

Abstract

Multiple reservoir planning and management related to water resources mobilization within a river basin involves numerous rather complex physical, technological, economic and social aspects. Often, the most difficult engineering aspect of such a management planning effort is the development of a near optimal combination of reservoirs and water use facilities, their sizing, and sequencing. For large water resources system, the difficulty of the task is primarily due to the large number of possible alternative development and management strategies added with uncertainty of water inflow into the supply system. Any methodological approach to analyze the system should provide a rational guideline to decision making concerning interdependent water supply projects, and the elaboration of equipment programs, ensuring coherence and efficiency of various projects taking into account, the economic, social and environmental aspects and provide an objective information of the related organisms. For a large and complex system, a major challenge is to reduce the set of alternatives that need to be examined in detail to a reasonable number without mistakenly eliminating an attractive option. The most commonly suggested approach has been first to screen all alternatives with a mathematical programming technique to determine the most attractive alternative, then build a detailed simulation model of the most attractive alternatives. The simulation brings in the operation of various physical facilities, especially reservoirs- which significantly influence the alternatives. Therefore a combination of screening, reservoir operations study and ii simulation form an integrated approach to River Basin Planning and Management Study. The development of quick screening and rough simulation model supported by stochastic reservoir operation models, one used for sizing of the individual reservoir and the other used for development of rule curve for use in the simulation is the subject matter of this study. The specific problem is the screening of multiple reservoirs which is a subset of the river basin planning and is approached by a set of Techno - Economic and Management procedures called the TEAM-approach. The screening and sequencing of projects has been carried out by a two stage - two level - hierarchical analysis. In the first stage, development of discrete _economically viable projects, satisfying regional aspiration and environmental and social constraints is carried out. In the second stage, sequencing of projects is formulated as a integer 0-1 programming problem and is solved by a two level hierarchical heuristic procedure. A rough hydraulic simulation model is developed to examine the interaction of reservoirs. The distinguishing feature of this River Basin Simulation (RIBS) is its simplicity, the principles of allocation of water using a double sweep, once from upstream to downstream and then from downstream to upstream to meet all demands according to priorities and the reservoir management rules. Actual releases are affected from upper most reservoir downstream to account for return flows. The reservoir is zoned into components and each zone is assigned with release priorities. The double sweep concept is used to take maximum advantage of uncontrolled flows and iii allocation of reservoir waters under shortage conditions. The operation of reservoir is studied both for fixing of storage for flood control in developing discrete project levels and also to evolve an optimal operation policy which can be incorporated into the simulation. Both these models are formulated as stochastic dynamic programming models and are solved by policy iteration and successive approximation. A river basin LUSI - SERANG which is the eastern part of JRATUNSELUNA basin in Central Java Indonesia is analyzed to demonstrate the concept, efficiency and the appropriateness of the approach. The monthly critical flow sequence is used in initial screening and the historical inflow of 20 years is used in simulation and in deriving data for reservoir operation studies. Based on the results, it can be concluded that the approach is simple and can easily be used to analyze River Basins with personal computers. Several computer programs have been developed for supporting the screening, sequencing, reservoir operation and simulation studies. These programs shall be helpful in making task of analyzing river basin planning more realistic.