基于区间两阶段随机规划方法的 北京市水资源优化配置

针对缺水型城市水资源配置过程中的不确定性,建立了基于不确定性基本理论的区间两阶段随机规划模型,应用于北京市2025年水资源优化配置的研究。以北京市用水综合效益最大为目标函数,引入概率分布和区间数表示多重不确定性,求得北京市2025年城六区与郊区在生活、工业、农业与生态用水上的优化供水目标以及不同来水水平下的配水方案。结果表明:北京市2025年优化供水目标为47.39亿m~3,城六区工业用水与郊区农业用水的供水目标应采取保守值;不同来水水平下的优化配置水量为36.49,47.39]亿m~3,仅北京为丰水年时不存在缺水现象,北京与丹江口水库同时遇枯时的缺水量高达5.48,10.90]亿m~3,对北京市供水安全造成极大的威胁。该模型充分考虑不确定因素对水资源配置的影响,权衡用水收益与缺水风险的关系,并以区间的形式给出配置结果,可为北京市2025年供水目标与水资源优化配置方案的制定以及水资源安全保障措施的分析提供科学依据。

Optimal water resources allocation based on interval two2stage stochastic programming in Beijing

Considering the uncerta int y in the w ater resour ces allocatio n pr ocess of w ater2deficient cities, an interv al tw o2stag e sto chastic pro g ramming mo del w as established fo r the study o f o ptimal water resource a llo cation in Beijing for 2025. T his model took the max imum compr ehensive benefit of wat er use in Beijing as the objectiv e funct ion, intr oduced probability distributio n and interv al number to represent multiple uncertainties, and obtained the optimal w ater supply objectiv es and w ater distributio n schemes under different levels of w ater inflow for liv ing, industrial, ag ricultural and eco lo gical w at er use in six urban areas and subur bs o f Beijing fo r 2025. T he r esults show ed that t he o ptimal w ater supply ta rg et of Beijing in 2025 w as 4. 739 billion m3 , and the water supply t arg et of industrial w ater in six ur ban areas and ag ricultur al water in suburbs should co nserv ativ e. T he optimal allocation o f water under different levels of inflow was 31 649, and 41 739] billion m3 , r espectively, and there w as no water sho rtag e when t her e was a hig h flow year in Beijing . Likew ise in the same periods, the water shortage was 01 548, and 11 090] billion m3 , r espectiv ely, w hen ther e w as a low flow y ear in Beijing and Danjiang kou r eser voir. This scena rio posed a g reat threat to t he w ater supply security o f Beijing. This mo del fully co nsidered the impact o f uncertain factors on water resources al2 locatio n, evaluated the relat ionship betw een water use benefits and water shortage risks, and o bta ined the allocatio n results in the fo rm o f interval. T his study can pr ov ide a scientific basis for the fo rmulat ion of w ater supply objectives and optimal alloca2 tion of w ater r eso ur ces as w ell as t he analy sis of w ater r eso ur ce securit y measur es in Beijing fo r 2025.