Hedging Rule을 利用한 漢江水系 多目的댐 連繫 運營 最適化 = Optimization of multi-reservoir operation with a hedging rule in the Han river basin

다국어 초록 (Multilingual Abstract)

The major reason to construct large dams is to strore suplus water during rainy seasons and utilize it for water supply in dry seasons. Reservoir storage has to meet a pre-defined target to satisfy water demands and cope with a dry season when the availability of water resources are limited temporally as well as spatially. It is hard to determine reservoir operation policy because of the uncertain future data. In this study, a Hedging rule that reduces total reservoir outflow as drought starts is applied to alleviate severe water shortages. Five stages for reducing outflow based on the current reservoir storage are proposed as the Hedging rule. The objective function of this approach is to minimize the total discrepancies between the target and actual reservoir storage, water supply and demand, and required minimum river discharge and actual river flow. Mixed Integer Linear Programming (MILP) is used to develop a deterministic multi-reservoir operation system with the Hedging rule. However, this system does not consider the future uncertainties so the results cannot used as a hedge against the possible system failure due to the future realization. Two-stage stochastic linear programming(2-SLP), thus, is developed with the basically same objective function. The reservoir storage is determined in the first stage before knowing the future conditions and then, in the second stage when the future realization is determined, the water distribution to users and over the stream is designed. The inflow to the basin and water demand of users are considered as the uncertain data and various scenarios were examined to consider future uncertainty.
The developed systems are applied in the Han River basin that includes four multi-purpose dams and one water supplying reservoir. One of the four multi-purpose dams is primarily for power generation. Ten-day-based multi-reservoir system is developed and optimized by GAMS/CPLEX which is LP/MIP solver using a branch-and-cut algorithm. As results, most demands are satisfied when no uncertainty is involed in the system, and the discrepancies between reservoir target and real storage is more decreased than the real operation in year 2003. Only the most upstream subbasins where are no other water sources rather than natural inflow experienced water shortage at some periods. When the future uncertainties on the basin outflow and water demands are involved in the system, the water shortage of users and reservoirs in the system become severe under the extreme future conditions. Therefore the results can provide the guideline for preparing a emergency action plan under the various future climate and demand conditions.

목차 (Table of Contents)

• 제 1 장 서 론 1
• 1.1. 연구배경 1
• 1.2. 연구목적 및 내용 2
• 제 2 장 연구 동향 4
• 2.1. 댐 운영 방법에 관한 연구 4
• 2.1.1. Standard Operating Policy(SOP) 4
• 2.1.2. Space Rule 4
• 2.1.3. Packing Rule 5
• 2.1.4. Hedging Rule 5
• 2.2. 댐 최적 운영에 관한 연구 6
• 제 3 장 다목적댐 연계운영 모형 8
• 3.1. 네트워크 구성 8
• 3.2. 다목적댐 연계운영 모형을 위한 Hedging Rule 9
• 3.3. 확정론적 다목적댐 연계운영 모형 11
• 3.3.1. 혼합정수 선형계획법 11
• 3.3.2. 확정론적 다목적댐 연계운영 모형 구성 11
• 3.4. 추계학적 다목적댐 연계운영 모형 16
• 3.4.1. Latin Hypercube 추출법 16
• 3.4.2. 2단계 추계학적 선형계획법 17
• 3.4.3. 추계학적 다목적댐 연계운영 모형 구성 19
• 제 4 장 한강수계에의 적용 23
• 4.1. 한강수계 기초자료 23
• 4.1.1. 대상 유역과 네트워크 23
• 4.1.2. 입력자료 25
• 4.2. 적용 결과 36
• 4.2.1. 확정론적 다목적댐 연계운영 모형 36
• 4.2.2. 추계학적 다목적댐 연계운영 모형 43
• 제 5 장 결 론 74
• 참 고 문 헌 76