Optimal Design of Barrage Profile on Anisotropic Soil Using Multi‐Objective Optimization Approach

Weirs and barrages are costly hydraulic diversion structures; therefore, any attempt to improve their design is a worthy contribution. Diversion structures, such as weir or barrage, may be designed on permeable formations considering homogenous soil properties. But in reality, soil properties are hardly homogeneous. In this paper, an approach is described to determine an economically efficient barrage profile by considering soil’s anisotropic behaviour. Hydraulic conductivity is considered to be an anisotropic soil property. An optimization-based methodology is developed to obtain the optimal barrage profile. The minimization of the material cost and minimization of the exit gradient is considered for multi-objective formulation. The multi-objective formulation is solved using NSGA-II, and a Pareto optimal front is obtained for different degrees of anisotropy. The flow interaction under a diversion structure in anisotropic soil is incorporated using the Modified Lane theory and is embedded in optimization formulation. The developed methodology is illustrated with a barrage profile as a hydraulic structure. A parametric study is carried out to study the effects of varying barrage design elements on the barrage’s optimum material cost.

     

共青河泄洪闸除险加固工程试验研究

共青河泄洪闸下游河道由于人为过量挖沙导致下游河床下切、水位降低 ,泄洪闸泄洪造成了下游左堤岸决堤。共青河泄洪闸除险加固工程方案的试验研究表明 ,在泄洪闸原消力池下游设置二级消力池 ,能较为妥善地解决消力池出流与下游河道水流衔接过渡的问题。     

改进遗传算法在高非线性水质模型参数估值中的应用研究

在标准遗传算法的基础上,提出了一种采用精英保留策略、小生境技术、适应函数调整,同时又能自适应地改变交叉和变异概率的改进遗传算法,使得算法在高维复杂水质模型多参数估值搜索时,不丢失最优解空间和后期有效分辨最优适应度。以测试函数Rastrigin为验证,得到了已知的最优结果;最后,以下水道高非线性水质模型的参数优化估值问题为实例进行验证,将优化后的水质参数代入模型中,模拟所得结果与给定的实测值吻合良好,实现了高维复杂水质模型多参数的同时估值优化功能。该算法对其他高非线性水质模型参数优化问题同样具有较好的适用性。     

海河口闸下泄流拖淤分析

海河口属淤泥质河口，其档潮闸下引河淤积问题极为严重，挖泥清淤虽然有效，但费用之高愈来愈连以承受，利用闸上有限泄流或闸下落潮流拖淤，寻找一种简捷，经济的清淤措施已引起海河流域水管部门的极大兴趣，本文对１９９４年海河干流挡潮闸下拖淤情况进行了全面的介绍和分析。     

Non-Uniform Flow Effect on Optimal Waste Load Allocation in Rivers

In this study, the effects of non-uniform flow due to: (i) inflow from tributaries and (ii) the presence of a downstream control structure (such as a weir or a barrage), on the optimal waste load allocation decision and the resulting cost-equity trade-off relationships, have been investigated. These effects are illustrated with in the framework of a typical cost-equity multi-objective optimization model for optimal waste load allocation in rivers. This framework consists of an embedded river water quality simulator with gradually varied flow and transport (BOD-DO) modules and a cost-equity multi-objective optimization model. A multi-objective evolutionary algorithm known as Non-dominated Sorting Genetic Algorithm-II is used for solving the optimization problem. The optimal fraction removal levels, the treatment cost and the system inequity measure are under predicted in certain reaches of the river, if the uniform flow assumption is made, while actually non-uniform flow conditions exist. This effect is quite pronounced when the flow non-uniformity results from a downstream control structure such as a weir.     

基于MATLAB 7.0的GA工具箱在渡槽优化设计中的应用

针对工程优化问题中的多变量、复杂非线性约束条件，运用GA工具箱，对某渡槽结构进行优化，得出了令人满意的优化结果。研究表明，遗传算法工具箱使用简单方便，且能根据不同的优化指标、计算精度寻找出最佳结果，充分体现了遗传算法的全局搜索性能。本优化方法具有计算可靠，快捷高效和图形结果可视化等特点，并具有广阔的应用前景。     

Development of Optimization Schemes for Floodplain Management; A Case Study

In this paper, two optimization models are presented. The first model is developed to determine economical combination of permanent and emergency flood control options and the second one is used to determine the optimal crop pattern along a river based on the assigned flood control options by the first optimization model. The optimal combination of flood protection options is determined to minimize flood damages and construction cost of flood control options along the river using the genetic algorithm (GA) optimization model. In order to consider the effects of flood control options on hydraulic characteristics of flow, two hydrological routing models for the reservoir and the river are coupled with the optimization model. Discharge–elevation and elevation–damage curves obtained based on separate hydraulic simulations of the river are used for flood damage calculations in the optimization model. The parameters of a hydrologic river routing model are also calibrated using the developed hydraulic model results. The proposed model is applied to the Kajoo river in the south-eastern part of Iran. The results demonstrate an economical integration of permanent and emergency flood control options along the river which include minimum expected value of damages related to floods with different return periods and construction cost of flood control options. Finally the resulting protection scheme is used for land use planning through identifying the optimal crop mix along the river. In this approach, the objective function of the optimization model is an economic function with a probabilistic framework to maximize the net benefit of agricultural activities. The study exhibits the importance of floodplain management and land use planning to achieve the development goals in the river basins.     

基于监测成果评价流溪河某拦河坝渗流稳定性

以流溪河某拦河坝渗流监测数据为基础,选取部分代表性的监测数据,在剔除异常数据后,利用实测监测数据分析拦河坝加固后防渗效果,重点分析加固后消力池连接段实测扬压力变化情况,根据监测数据综合评价了拦河坝渗流稳定性,监测成果表明防渗墙加固后,坝基的防渗效果得到加强,解除了拦河坝的险情,分析思路和方法可为同类工程提供借鉴。     

基于遗传算法的灰色非线性水环境管理模型及应用

以郑州市贾鲁河水环境治理规划为基础,统筹考虑到治理区域内的工程建设、水环境改善策略、污水处理厂建设运行以及配套水库调度等,构建了灰色非线性水环境管理模型,并选择遗传算法作为计算手段,对该模型进行了求解。构建的模型同时考虑到了治理区域内的污水处理厂优化运行、南水北调补水、区域内3个生态湖泊与治理河段的净化能力等。通过优化运行协调,实现了运行费用经济合理、水生态环境改善、水质达标等多项治理目标。研究结果表明,基于遗传算法的灰色非线性规划在区域水环境治理中的应用潜力十分显著。     

复杂河网引清流量优化分配模型

根据物质守恒原理,建立复杂河网引清流量优化分配模型,以实现引清调度优化。鉴于模型中河段水质与流量的隐函数关系,利用罚函数法进一步优化模型的非线性约束,使河段水质目标呈隐式表达形式,达到减少决策变量与约束条件的目的。建立不同初始点为搜索起点,利用模式搜索法对优化模型进行求解。求解结果表明,不同初始点对求解结果影响明显。进一步分析河段污染物衰减的影响因素,并以参数形式表征水动力的影响,从而建立河段引清流量的修正模型。将修正模型应用到福州内河的引清流量计算中,计算结果表明,修正计算结果比试算法结果减少7.2 m3/s,大大减少了引清流量,较好实现了引清流量的优化分配。     

旋流阻塞复合式泄洪洞的水力特性（1）

对旋流阻塞复合式泄洪洞的体型设计进行探讨,并通过模型试验对其流态和水力特性进行了研究。阻塞对水流流态有明显的影响,水平旋流阻塞复合式洞的水流流态可划分为不完全旋流以及完全旋流2种基本流态。泄流能力由起旋器与阻塞共同控制,阻塞孔径对泄流量影响较大,但阻塞位置对流量影响不明显。如考虑阻塞的影响,泄流量计算公式的形式可不变。阻塞影响系数ξ与d/D的关系近似为线性关系。阻塞对通气孔的通气状态产生明显影响：不同阻塞设置位置相同时,阻塞孔径越大,通风量越大;相同阻塞设置位置不同时,越靠近下游,通风量越小。     

Chance Constrained Optimal Design of Composite Channels Using Meta-Heuristic Techniques

Optimal design of irrigation channels has an important role in planning and management of irrigation projects. The input parameters used in design of irrigation channels are prone to uncertainty and may result in failure of channels. To improve the overall reliability and cost effectiveness, optimal design of composite channels is performed as a chance constrained problem in this study. The models are developed to minimize the total cost, while satisfying the specified probability of the channel capacity being greater than the design flow. The formulated model leads to a highly non-linear and non-convex optimization problem having multimodal behavior. In this paper, the usefulness of two meta-heuristic search algorithms such as Genetic Algorithms (GA) and Particle Swarm Optimization (PSO) are investigated to obtain the optimal solutions. Two site specific cases of restricted top width and restricted flow depth are also analyzed. It is found that both the algorithms performing quite well in giving optimal solutions and handling the additional constraints.     

基于遗传算法的拱坝优化设计

将寻优能力很强、具有全局最优解的遗传算法 ,应用于拱坝坝形的优化设计 .拱坝优化设计实例表明 ,采用遗传算法的优化设计结果优于序列二次规划法     

求直线供水边界抽水试验水文地质参数的解析法

直线供水边界条件下非稳定流抽水试验求解水文地质参数的超越方程涉及3个(在已知供水边界方向,未知位置的条件下)或4个(在供水边界方向和位置均未知的条件下)未知数,常规的解析法无法直接求解。现有的特定标准曲线比对法、图解拐点法、简化算法、非线性最小二乘法及二元线性回归法要么依赖图表、计算过程繁复,要么应用范围受限、计算结果误差较大,不便实际工程应用。采用优化拟合方法,在工程适用参数范围内,用较为简单的函数实现了对泰斯非稳定流井函数的替代,并利用水位降深比值关系式,经整理获得了可直接完成参数求解的简化解析式,计算过程简捷,便于实际工程应用。     

Thermodynamic analysis for a third grade fluid through a vertical channel with internal heat generation

This paper makes the thermodynamic analysis in forced convective flow of a third grade fluid through a vertical channel. Due to the reactive nature of the fluid, the effect of internal heat generation is considered and assumed to be a linear function of temperature. The coupled nonlinear dimensionless ordinary differential equations governing the fluid flow are solved by using the Adomian decomposition method(ADM). The effects of various physical parameters such as third grade material parameter, buoyancy parameter and heat generation parameter on the thermal structure of flow are presented and discussed.     

跨流域补偿调节的梯级水电站主要参数优选

本文应用非线性规划,优选规划阶段的水电站群的主要设计参数,并提出了相应的数学模型和算法。这一模型能较好地适应水电系统大规模和非线性的特点,在考虑水电站群跨流域补偿调节的条件下,同时优选各个水库的正常蓄水位和死水位,同时优选各水电站的最佳装机规模及其装机程序,使规划期内全电力系统的总费用现值最小。 本文曾结合某电力系统,对分布在四个不同流域上的五座具有不同调节性能的水库,和十一个水电站所组成的系统,对待建水电站进行了参数优选,得到了比较满意的结果,已提供有关部门在规划阶段中参考。     

SCE-UA算法在水环境系统优化问题中的应用

把SCE-UA算法应用到水环境系统优化问题的求解中,通过对问题的预处理,求解3个典型的优化问题：①二维稳态水质模型横向扩散系数及流速推求;②排放口最优化处理;③水工建筑物优化调度。结果表明：SCE-UA算法不但能求解一元函数约束的优化问题,通过构造罚函数,还能够成功求解有多元函数约束的优化问题。认为该算法不依赖导数和优化问题的具体形式,所需参数极少,求解精度高,通用性较强,值得在环境系统优化中推广。     

Impact of Declining Trend of Flow on Harike Wetland,India

Harike wetland in the Indian state of Punjab is formed by a barrage built downstream on the confluence of rivers Satluj and Beas, with the idea of storing and providing irrigation and drinking water to parts of Southern Punjab and adjoining Rajasthan. Due to decrease in flow at Harike and deforestation etc. in the catchment area, the wetland is reducing in the last few years. In this study, the analysis of rainfall/runoff data has been carried out to see the effect of decreasing trend of runoff on wetland area. Wetland area has been delineated using remote sensing technique. The analysis of rainfall, discharge and ground water level showed that the flow pattern is decreasing at Harike. The remote sensing data revealed that the wetland area has reduced approximately 30% over the last 13 years.     

Cost and Flooding Probability Minimization Based Design of HBPS Channel

This study proposes to use the channels having horizontal bottom and parabolic sides (HBPS) as substitute for trapezoidal channels. The acceptability of HBPS channel is contested by using the criteria of minimization of cost and flooding probability. An optimization model is developed to minimize the total cost of construction and flooding probability. The bi-objective model is solved by using the constraint method of multiple objective optimization technique. The objective of minimizing the flooding probability is converted to the flooding probability constraint. The first order analysis is used to develop the flooding probability constraint equation. The optimization model is solved by using projected augmented Lagrangian method. The optimization model is applied for design of HBPS and trapezoidal cross sections considering the composite and uniform roughness cases. The application results show that the objectives of minimizing the flooding probability and the total costs conflict each other when the desired flooding probability values are less than the value that occur at the traditional minimum cost design of the channels. The new HBPS cross section is found to remain cheaper than the traditional trapezoidal cross section. The developed optimization model has a potential for practical use.     

基于系统微分响应的暴雨强度公式参数优化

暴雨强度公式参数的优化求解本质是一个高维非线性优化问题,目前常采用的优化求解方法是在以误差平方和为目标函数的基础上通过智能算法优化求解参数。为研究这类方法的合理性,通过随机抽样、参数空间网格化方法分析了常用暴雨强度公式参数求解方法的局限性,评价了常用智能算法的参数优化能力,进而提出了基于系统微分响应的暴雨强度公式参数优化方法。结果表明：以均方误差作为目标函数对非线性函数求解参数会增加额外参数解;在没有有效确定参数范围的情况下,随机抽样很难获得满足精度要求的参数样本,在有效确定参数范围后,目标函数的响应面上仍会存在无穷多个局部最优值,且很多局部最优的目标函数与全局最优近乎相同;以粒子群算法、SCE-UA算法为代表的随机搜索优化算法会因为参数初始取值范围过大、目标函数响应面局部最优参数解数量过多等问题而难以获得参数真值;提出的基于系统微分响应的暴雨强度公式参数优化方法能够快速寻找到参数真值,不仅效率高且能够避免陷入局部最优。