流域防洪联合调度下工程防洪风险分析与转移规律研究

The flood disaster occupies various kinds of natural disasters. The joint operation of food control by engineering system in river basin is the most effective method to improve the engineering benefit for flood control. However, the uncertainties in hydrology and hydraulic affect the joint operation of flood control which restrict the performance of this technology in the practical application. This program studies flood control risk characteristics and risk-based decision-making of joint operation in the middle reaches of Huai River. The main contents include the following: (a) the coupling dynamics model of river flow as well as optimization model and the rule-based model for reservoir, embankment and flood storage basin in joint operation of flood control with the corresponding calculation method; (b) the recognition of the combination of flood distribution and uncertainty in river flow hydraulic evolution and analysis of flood control risk rate of reservoirs, embankments, flood storage projects as well as their spatial characteristics; (c) comparison of engineering flood control risk transfer regular pattern between existing rule-based operation and joint optimization operation, and the division of threshold which allows the transfer of risk and using risk decision-making method of multi-objective flood control for the safety guidance of decision. This project aims to reveal the spatial distribution characteristics of flood control engineering risk under the joint flood control operation, and compare to the risk transfer regular pattern of existing rules which lay the theoretical foundation and technical basis for the comprehensive flood control and the safety evaluation of engineering flood control.

洪水灾害占据各种自然灾害的首位，流域工程系统的防洪联合调度是提升工程防洪效益的最有效手段，然而防洪联合调度中的水文、水力等不确定性因素的影响，制约了该项技术在实际应用中有效被执行。本项目以淮河中游水系为研究背景，对联合调度中的工程防洪风险特性及风险决策进行基础科学研究，主要内容有：耦合河流水动力学模型，构建水库、堤防、蓄滞洪区防洪联合调度的确定性优化模型和规则模型，以及相应的计算方法；识别洪水空间组合分布、河道水流水力演进的不确定性，分析水库、堤防、蓄滞洪区工程防洪风险率及其空间分布特性；对比现行规则调度和联合优化调度下的工程防洪风险空间转移规律，划分允许风险转移阈值，利用多目标风险决策方法指导防洪调度安全决策。本项目旨在揭示防洪联合调度下的工程防洪风险的空间分布特性，以及对比现行规则调度下的风险转移规律，为有效地进行综合洪水管理和工程防洪安全评估奠定理论基础和技术基础。

流域和区域洪水威胁是世界各国每年都需要面对的重大问题，深入开展洪水风险相关研究对于实现“从控制洪水向洪水风险管理”理念转变具有重要的科学意义和现实意义。本项目立足我国不同地区典型流域和区域防洪风险分析需求，采用了理论分析、数学模型的方法，研究提出了典型流域工程系统联合调度水文水动力学耦合模拟模型的建模方法与求解方法，分析了典型流域径流时空分布特征，构建了淮河干流、苏南运河等区域防洪排涝全过程水文水动力数学模型，模拟计算了流域/区域内不同暴雨洪水情景，实现水库、堤防、水闸、泵站等不同水利工程部件的防洪调度规则表征，编制了典型河流洪水风险区划图。重要结果及关键数据如下：.（1）在城市区域，考虑城市河道、地下管网、排水系统设施、闸泵水利工程及其调度的防洪、排涝、排水不可分割，需融合防洪排涝与排水关系，系统考虑防洪风险分析。以景德镇为对象，研究构建了其耦合的暴雨洪水水文模型、河道一维水动力模型及排涝片区模型，模拟分析现状和规划条件下不同重现期设计洪水的风险情况；基于Infoworks ICM软件，构建了苏南运河沿线平原河网精细化水文水动力模型，模型构建范围涉及2.16万km2；在淮河干流洪水模拟水动力模型中，提出采用PSO算法进行糙率系数校正，得到的值比人为经验估计平均大0.01，河道水位、流量过程与实测值拟合更优。.（2）在雅砻江流域，各控制站点特枯年份下基尼系数均介于0.3-0.4之间，表明天然径流年内分配相对均匀，但各控制站点偏丰和特丰年份下基尼系数均介于0.4-0.5之间，表明天然径流年内分配比较不均匀，径流时程分布主要受降雨影响；7座电站水库的水足迹范围为0.01-2.91 m3GJ-1，平均水足迹为1.13 m3GJ-1，小于其他同等空间尺度研究的水足迹，水电站水足迹主要受能效因子和地形因子双重影响。.（3）在沭河大官庄以上，综合考虑了水库泄洪、河道行洪、堤防溃决以及防洪保护区淹没等情景条件，利用将洪水风险等级分为低风险、中风险、高风险、极高风险4个等级，计算网格的综合风险度R指标，采用R<0.15为低风险，0.15≤R<0.5为中风险，0.5≤R<1为高风险，R≥1为极高风险的规则，研究绘制了洪水风险区划图。