基于CPLEX的水库群联合供水优化调度研究

Optimized joint water supply scheduling of reservoir groups using CPLEX

摘要

【目的】随着极端干旱天气的频发,城市水资源短缺是快速城镇化进程中面临的共性挑战。为缓解供需紧平衡条件下的城市缺水问题,建立一套基于线性规划的城市多水源联合供水优化调度模型及联合调度规则提炼技术体系。【方法】以昆明市主城区为例,采用CPLEX线性规划以及分层序列法构建了水库群联合供水优化调度模型,考虑水源工程在不同库容条件下供水能力变约束,利用1956—2021年长系列来水,针对2021年、2025年需水进行了优化调度研究,基于优化调度过程总结调度规则,提出了保障昆明城区供水的水库群联合调度方式。【结果】结果表明,1956—2021年昆明市主城区常规水源水库群多年平均径流量为6.21亿m³。2021年实际需水量约4.80亿m³,2025年预测需水量约5.88亿m³。在2021年和2025年需水条件下,常规水源联合调度的供水保证率分别为86%和57%。在考虑德泽水库联合调度后,供水保证率分别提升至92%和74%。从各供区缺水成因看,主城片区中,因云龙水库供水能力限制引起的缺水占67.9%,因水资源不足导致的缺水占32.1%;而清水海片区的缺水则100%由水资源不足引起。【结论】结果表明:昆明市主城区供水处于供需紧平衡条件下,遭遇偏枯或特枯年,供水将面临较大挑战,资源性缺水与工程输水能力限制是导致缺水的主要原因;利用CPLEX构建的水库群联合调度模型可有效协调多水源协同供水过程,通过优化调度基本可以解决2021水平年条件下的缺水问题,也可以明显缓解2025年条件下的供水紧张形势;基于优化调度过程,研究提出了适应供需特征和工程体系的“主水源稳供、辅助水源调剂、散小水源补充”调度规则,可为昆明市水源水库群联合供水调度提供参考。通过本次昆明主城区供水调度模拟,展示了利用CPLEX线性规划求解器进行水库群联合优化调度的适应性,进一步探索了基于优化调度过程的水库群联合调度规则提炼方法,可为类似缺水地区的多水源供水优化调度提供理论依据与实操框架。

Abstract

[Objective] With the frequent occurrence of extreme drought weather, urban water shortage has become a common challenge during rapid urbanization. To alleviate urban water shortage under tight supply-demand balance conditions, a technical framework for the construction of an optimized joint water supply scheduling model for multi-source urban water supply and the extraction of joint scheduling rules based on linear programming is established. [Methods] Taking the main urban area of Kunming as an example, a joint optimized scheduling model for water supply of reservoir groups was developed using CPLEX linear programming and the lexicographic method. The variable constraints of water supply capacity of water source projects under different storage conditions were considered. Using the long-term inflow series from 1956 to 2021, optimized scheduling studies were conducted for water demand in 2021 and 2025. Scheduling rules were summarized based on the optimized scheduling process, and a joint scheduling method for the reservoir groups to ensure water supply for the urban area of Kunming was proposed. [Results] The result indicate that the average annual runoff of the conventional water-source reservoir group in the main urban area of Kunming from 1956 to 2021 is 0. 621 billion m³. The actual water demand in 2021 is approximately 0. 480 billion m³, and the forecasted water demand in 2025 is about 0. 588 billion m³. Under the water-demand conditions of 2021 and 2025, the water-supply guarantee rates of joint dispatching of conventional water sources are 86% and 57%, respectively. When the Dez e Reservoir is included in the joint operation, the water-supply guarantee rates increase to 92% and 74%, respectively.Regarding the causes of water shortage in each supply zone, in the main urban area, 67. 9% of water shortages are attributed to the supply capacity limitations of Yunlong Reservoir, while 32. 1% are caused by insufficient water resources. In contrast, water shortages in the Qingshuihai area are entirely(100%) due to insufficient water resources. [Conclusion] The result indicate that the water supply in the main urban area of Kunming is under tight supply-demand balance conditions. When encountering dry or extremely dry years, the water supply will face great challenges. Resource-based water shortage and limitations in engineering water transmission capacity are the main causes of water shortage. The joint scheduling model of reservoir groups constructed using CPLEX can effectively coordinate the synergistic water supply process of multiple water sources. Through optimized scheduling, the water shortage problem under the normal year conditions in 2021 can be basically solved, and the water supply pressures under the conditions in 2025 can be significantly alleviated. Based on the optimized scheduling process, scheduling rules of “stable supply from primary water sources, regulation by auxiliary water sources, and supplementation by scattered small water sources” which adapt to the supply-demand characteristics and engineering system are proposed. These rules can provide a reference for the joint water supply scheduling of the water source reservoir groups in Kunming. Through the water supply scheduling simulation of the main urban area of Kunming, the adaptability of using the CPLEX linear programming solver for the joint optimal scheduling of reservoir groups is demonstrated, and a method for extracting joint scheduling rules for reservoir groups based on the optimized scheduling process is further explored. This can provide a theoretical basis and a practical framework for the optimized scheduling of multi-source water supply in similar water-scarce areas.

关键词

多水源调度 / 线性规划 / 分层序列法 / 水资源管理 / 城市供水 / 昆明市 / 应急供水 / 影响因素

Key words

multi-source water scheduling / linear programming / lexicographic method / water resources management / urban water supply / Kunming City / emergency water supply / influencing factors

基金资助

国家自然科学基金项目(U2340211)

长江勘测规划设计研究有限责任公司自主科研项目(CX2024Z04-1)