河道—泛区二维水动力耦合数值模拟及其在洪水风险分析中的应用

发布时间：2018-04-10 06:27

本文选题：河道-泛区　切入点：二维水动力模型　出处：《天津大学》2014年硕士论文

【摘要】：由于水土流失严重且河道淤积加剧,洪水特征渐向峰现提前、洪量骤增及洪水历时短发展,以致洪灾频繁发生,造成重大生命财产损失。目前,我国正处于由控制洪水向洪水管理的转变时期,综合采用工程措施和非工程措施应对洪灾是防洪减灾事业发展的必然趋势。对洪水管理区域建立水动力数值模型,模拟洪水演进全程并获得淹没水深、洪水流速、淹没历时及到达时间等洪水风险信息,并基于此绘制淹没区洪水风险图,已成为防洪减灾非工程措施建设的必要组成部分。本论文在防洪减灾非工程措施全面建设背景下,所做研究包含以下结论:(1)结合当前洪水特征发展态势及所致洪灾特点,针对多种模型无法模拟溃口附近水流复杂流态及水力要素动态衔接问题,提出河道-泛区二维水动力动态耦合模型理论,并据此建立模型。(2)采用多种技术措施对所建河道-泛区二维动态耦合水动力数值模型进行优化,主要包括:考虑溃口展宽、漫溃堤分流理论、热启动和溃口形状变动处理技术实现河道与堤防动态无缝耦联;利用干水深和湿水深理论提高模型稳定性和运算效率;综合采用糙率分区法和真实地形法解决密集构筑物对水流运动的影响;综合遥感影像、DEM和实测断面数据还原河道地形。(3)研究洪水风险分析方法、风险分析与模型检验方法、洪水影响评估与避险转移分析及风险图绘制,为洪水分析计算及风险图绘制提供技术理论支撑。(4)为满足黄河内蒙段冰凌封开河漫堤及汛期溃堤的洪水风险分析需求,对河道及两岸灌区建立二维动态耦合水动力数值模型,实现漫堤和溃堤洪水联算功能,模拟分洪洪水在灌区内的演进情况,并根据计算结果绘制洪水风险图。(5)根据黄河宁夏段漫滩及堤防风险分析需求,对河道及青铜峡河东防洪保护区建立二维动态耦合水动力数值模型,实现河道洪水自由漫滩和溃堤洪水联算功能,模拟洪水漫滩运动及其在防洪保护区二维平面内的演进情况,并基于模型计算结果绘制洪水风险图。本文所建河道-泛区二维动态耦合水动力数值模型考虑了漫、溃堤位置处流态的复杂变化,弥补了一、二维耦合模型的不足,并可实现二维宽浅河道漫滩、漫堤、溃堤及其任意组合的洪水联算,为相关部门制定避险转移路线、评估洪灾损失及防洪管理决策提供技术支撑。
[Abstract]:Due to serious soil and water loss and aggravation of river siltation, flood characteristics gradually peak ahead of schedule, flood volume increases and flood duration is short, which results in frequent flood and great loss of life and property.At present, China is in the transition period from flood control to flood management. It is an inevitable trend of flood control and disaster reduction to adopt comprehensive engineering and non-engineering measures to deal with flood.The hydrodynamic numerical model is established for flood management area, and flood risk information such as flood depth, flood velocity, flood duration and arrival time are obtained by simulating the whole course of flood routing. Based on this, the flood risk map of flooded area is drawn.It has become a necessary part of non-engineering measures for flood control and disaster reduction.In this paper, under the background of comprehensive construction of non-engineering measures for flood control and disaster reduction, the research includes the following conclusions: 1) combined with the development trend of current flood characteristics and the resulting flood characteristics,In order to solve the problem of complex flow state and dynamic connection of hydraulic elements near the gully, a two-dimensional hydrodynamic coupling model theory is proposed.Based on the above model, model No. 2 is established. Several technical measures are adopted to optimize the 2-D dynamic coupled hydrodynamic numerical model of river channel and pan-area, which mainly includes: considering the widening of breakers and the theory of overflow and diversion of embankment.The dynamic and seamless coupling of channel and embankment is realized by the technology of hot start and change of burst shape, and the model stability and operation efficiency are improved by using dry water depth and wet water depth theory.The flood risk analysis method, risk analysis and model checking method are studied by comprehensive use of roughness zoning method and real terrain method to solve the influence of dense structures on water flow movement, and synthetic remote sensing image Dem and measured cross-section data to restore river topography.Flood impact assessment, risk avoiding transfer analysis and risk map drawing provide technical theoretical support for flood analysis and calculation and risk map drawing.) to meet the flood risk analysis needs of the flood risk analysis of the Bingling Fengkai River embankment and the embankment in flood season in the Inner Mongolia section of the Yellow River.A two dimensional dynamic coupled hydrodynamic numerical model is established for the river course and the irrigation area on both sides of the bank to realize the combined calculation function of the overtopping and break flood, and to simulate the flood routing in the irrigation area.According to the needs of flood bank and embankment risk analysis in Ningxia section of the Yellow River, a two-dimensional coupled hydrodynamic numerical model is established for river and Qingtongxia River East Flood Control Reserve.The combined calculation function of flood free floodplain and embankment flood is realized. The flood flood flood beach movement and its evolution in the two dimensional plane of flood protection area are simulated. The flood risk map is drawn based on the results of the model calculation.In this paper, the two-dimensional coupled hydrodynamic numerical model of river channel and pan-area has considered the complex variation of flow state at the location of overflowing and break embankment, which makes up for the deficiency of the first and two-dimension coupling model, and can realize the two dimensional wide and shallow channel flooding and overtopping.The combined calculation of the breakwater and its arbitrary combination provides technical support for the relevant departments to formulate the route of avoiding risk and to evaluate the flood loss and the decision of flood control management.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV122

【引证文献】