成本-收益-风险三元驱动的大坝退役评估决策方法研究

Dam decommissioning, as an important stage of the entire dam life-cycle, has been considered as an inevitable trend in developed countries under the background of dam aging, reservoir function-loss, recession of economic benefits and the resulting ecosystem degradation. However the basic theories and evaluation methods considering the subject in China is relatively underdeveloped. Based on the database of the decommissioned dams home and abroad and the relevant of downgraded and decommissioned cases, the measurement system for decommissioning assessment has been established; The slow-varying and sudden-varying features of the time-varying effect for the measure of the decommissioning assessment are characterized by highlighting the time-varying uncertainty according to certain probability distribution. By considering the impact of the sedimentation on the reservoir storage capacity, the additive effect between the dam operational time-varying risk and the reservoir sedimentation incremental risk is researched; Through conducting the investigation and field experiments of the corresponding river habitat, the river habitat is evaluated by the spatial contrast method based on GIS; The PSR evaluation model for the ecological influence of the dam retirement is then established to characterize the three logical relations, pressure-state-response, of the ecological measurement system. The subjective and objective six-point-scale measurement and evaluation method of the pressure-factor sector model under the tangential and radial dimensions is studied for the decommissioning measurement; Based on the round shooting diagram between the costs and benefits of the dam retirement, the systematic and transparent quantitative multicriteria decision-making model for the dam retirement is established based on the risk-driven theory. The research results are of certain theoretical and academic values for eradicating severe dam dangers, protecting the river ecological environments and improving the disaster-prevention and reduction system.

退役是水库大坝全生命期的重要阶段，在发达国家已成大坝病险老化、功能丧失、经济效益衰退及生态系统退化背景下的必然趋势，在我国的基础理论和评估方法则相对落后。基于国内外退役大坝数据库及降等报废案例，构建退役评估测度体系；按照一定概率分布突出时变不确定性表征退役评估测度时变效应的缓变和骤变特征，考虑水库泥沙淤积对库容影响，研究大坝运行时变风险与水库泥沙淤积增量风险的叠加效应；通过开展研究区河流生境调查与试验，基于GIS采用空间对比法评估河流生境；在此基础上建立表征生态环境测度体系压力-状态-响应三层逻辑关系的大坝退役生态环境影响PSR评估模型；研究退役测度压力因子扇形模型环向与径向维度主客观六点度量评估方法，以及基于风险驱动的大坝退役成本效益圆形分射图，建立系统化与透明化的大坝退役多目标决策量化模型。研究成果对根除大坝严重病险、保护河流生态环境、完善减灾防灾体系具有重要理论意义和学术价值。

项目以我国水库大坝中面广量大的土石坝为主要研究对象，基于病险、溃决、退役大坝数据库及典型退役工程案例，构建水库大坝退役评估测度体系；针对风险因子的“缓变”与“骤变”时效特性，建立水库泥沙淤积与工程运行风险叠加时变增量风险的分析方法；鉴于水库大坝退役可能引发的洪水和生态系统风险，模拟退役方案在雨洪和溃坝洪水发生时下游区淹没情况，评估社会、经济和生态三准则下的洪水风险；在此基础上，通过河流生境调研与试验，基于河流水生态系统和生物多样性时间累积与泥沙淤积空间叠加效应，建立退役生态系统价值时变评估模型；在此基础上，构建“收益-成本-风险”三元驱动的水库大坝退役评价向量，由“信息-特征-决策”信息融合理论建立多层次退役决策模型。发表相关学术论文27篇，其中SCI/EI检索论文10篇；出版英文专著一部，待出版中文专著两部；获批软件著作权6项；参编行业技术标准2部、团体标准1部；两项技术被列入《2020年度水利先进实用技术重点推广指导目录》；获中国标准创新贡献奖二等奖1项、中国大坝工程学会科学技术奖二等奖1项。研究成果对根除水库大坝严重病险、保护河流生态环境、完善减灾防灾体系具有重要理论意义和学术价值，目前部分研究成果已纳入水利行业技术标准，科学指导全国范围内的水库及水电站大坝降等报废评估工作。