基于和声搜索算法的地下水污染源与未知含水层参数的同步反演研究

地下水污染源反演问题和含水层参数反演问题都是典型的地下水逆问题。在未知含水层参数（渗透系数、弥散度等）等先决信息的情况下进行地下水污染源反演计算时,需要根据已有的监测数据（水位和浓度等）对地下水污染源和未知含水层参数进行同步反演。在同步反演优化问题中,决策变量包括污染源位置、强度以及待求的含水层参数。本文对同步反演模型的框架组成（包括污染物迁移模型和反演优化模型）进行分析后,在对已有的各种和声搜索改进算法进行研究的基础上结合同步反演模型提出一种改进的和声搜索算法,最后将同步反演模型和改进的和声搜索算法应用于具体的算例研究。研究表明,改进的和声搜索算法具有算法稳定高效、求解精度高等特点,能够广泛应用于复杂的地下水污染源和含水层参数反演问题。     

基于和声搜索算法的地下水污染源与未知含水层参数的同步反演研究

地下水污染源反演问题和含水层参数反演问题都是典型的地下水逆问题。在未知含水层参数(渗透系数、弥散度等)等先决信息的情况下进行地下水污染源反演计算时,需要根据已有的监测数据(水位和浓度等)对地下水污染源和未知含水层参数进行同步反演。在同步反演优化问题中,决策变量包括污染源位置、强度以及待求的含水层参数。论文首先介绍同步反演模型的框架组成(包括污染物迁移模型和反演优化模型),然后在对已有的各种和声搜索改进算法进行研究的基础上结合同步反演模型提出一种改进的和声搜索算法,最后将同步反演模型和改进的和声搜索算法应用于具体的算例研究。研究表明,改进的和声搜索算法具有算法稳定高效、求解精度高等特点,能够广泛应用于复杂的地下水污染源和含水层参数反演问题。     

用改进的遗传算法反演地下水数值模型参数

在简单的遗传算法的基础上，结合优体克隆操作、子体优生操作和多代调环操作，提出了一种综合改进的遗传算法，并以非均质各向同性承压二维非稳定流动为算例，以有限元法讨论了用遗传算法反演地下水数值模型参数的过程。计算结果表明，综合改进的遗传算法进行参数识别时，具有收敛速度快、解的精度高和避免出现早熟等优点，可用于地下水渗流和水资源评价计算中。     

基于大坝地震响应的参数反演方法研究

确定合理的参数是对基于大坝的地震响应进行正确分析的前提,利用反分析理论,探讨了大坝的力学参数确定方法。建立了地震荷载响应下的位移统计模型,推导出改进的目标函数形式,并结合遗传算法,以某大坝为例建立有限元模型,编制计算程序,对系统的力学参数进行优化反演,求出待定参数,进行对比验证。结果表明,反演所得参数准确,说明该方法合理可行,对分析大坝性态有重要参考价值。     

安阳市平原区浅层地下水对暴雨洪水的响应

在系统分析安阳市“7·19”特大暴雨洪水事件的基础之上,探讨典型极端降雨条件下安阳市东部平原区地下水对暴雨洪水事件的响应。在利用灰色关联分析法确定安阳市东部平原区浅层地下水水位和降雨量二者之间的相关程度的基础上,提出一种基于ArcGIS软件的地下水补给量计算模型。研究结果表明：安阳市平原区浅层地下水水位与降雨量的关联系数大于0.85,地下水资源量变化受降雨补给影响显著;“7·19”事件降雨强度大,雨量集中,受大范围强降雨影响,地下水位变幅沿河道向两岸方向没有形成递减的变化趋势,水位变幅与降雨分布呈正比;此次洪水为单峰型洪水,模型计算研究区地下水补给量为5.19亿m3,洪水转化率0.8 %。该计算模型适用于资料缺乏地区地下水补给量计算和雨洪资源化定量分析,对雨洪资源利用和地下水响应分析具有一定的参考价值。     

一维地下水溶质运移模型多参数反演

以一维地下水溶质运移模型为基础,利用微分进化算法重点探讨监测频次、测量误差等因素对纵向弥散系数DL、有效孔隙度n以及水流速度u等参数联合反演结果的影响,并构造瞬时源和连续源两种工况的典型案例来验证该方法的可靠性。结果表明：微分进化算法具有收敛速度快、精度高等特点,能够运用于瞬时源和连续源地下水溶质运移模型水力、水质参数的反演问题。     

江西柘林河段洪水的反演推求

马斯京根法是我国现行的河道流量演算方法中最常用的一种,在线性运动波演算中具有较高精度.马斯京根法反演主要用于河道断面资料缺乏的地区,通过下断面的洪水流量过程来反推求上断面的洪水过程.当坝址洪水资料缺失时,可以通过马斯京根法反演,分析建立入库洪水与坝址洪水的关系,使建库前后资料满足一致性.     

对设计洪水地下水回加计算的改进

对设计洪水地下水回加计算的改进应用《暴雨径流查算图表》进行设计洪水计算，在地下水回加计算确定地下水潜流峰值Ｑ＿０时，常常采用试错法进行。在实际工作中深深体会到，采用试错法要确定一个数，试算三五次是常有的事，弄不好试算次数还更多，工作量很大，这是该法的...     

基于井水位潮汐响应探讨含水层的水力特征及其变化

为了科学地认识应力荷载对地下水渗流运动规律的影响,揭示井孔-含水层系统与地震活动的响应关系,以华蓥山断裂带附近的大足井和北碚井为例,基于潮汐响应推求观测段含水层水力特征参数,探讨汶川地震对含水层水力特征及地下水流运动状态的影响,并对其变化机制进行解释。结果表明：大足井附近含水层中地下水运动以径向流为主,利用潮汐径向流模型计算出含水层水平渗透系数与以往抽水试验的结果基本一致;北碚井孔-含水层系统中地下水垂向流和径向流并存,引入越流含水层系统模型得到越流系数范围为1.5×10-8~2.5×10-8 s-1;汶川地震后,北碚和大足井水位均发生了阶降变化且含水层中地下水垂向流运动增强,分析认为原因是该区域侏罗系砂岩含水层在较大范围内存在着统一的水力联系,且局部裂隙发育,倾角较大,地震导致含水层发生膨胀变形和裂隙疏通,在重力作用下地下水顺层或沿裂隙通道流动。研究结果有助于提高对含水层受力变形与渗流相互作用的认识,进一步深化井孔-含水层系统对地震活动响应机制的研究     

Design Flood Estimation Using GIS Supported GIUHApproach

Quantitative understanding and prediction of theprocesses of runoff generation and its transmission to theoutlet represent one of the most basic and challenging areasof hydrology. Traditional techniques for design floodestimation use historical rainfall-runoff data for unithydrograph derivation. Such techniques have been widelyapplied for the estimation of design flood hydrograph at thesites of gauged catchment. For ungauged catchments, unithydrograph may be derived using either regional unithydrograph approach or alternatively GeomorhologicalInstantaneous Unit Hydrograph (GIUH) approach. The unithydrograph thus derived may be used for the simulation offlood events for the ungauged catchments. In this study Gambhiri dam catchment located inRajasthan, India is selected for applying this approach. Gambhiri river is a small tributary of the Berach/Banasriver of the Chambal basin in Rajasthan, India. Theobjective of the present study is to apply GeographicalInformation System (GIS) supported GIUH approach for theestimation of design flood. A mathematical model has beendeveloped at the National Institute of Hydrology, whichenables the evaluation of the Clark Model parameters usinggeomorphological characteristics of the basin. This modelhas been applied for the present study.From this study it is observed that the peakcharacteristics of the design flood are more sensitive tothe various storm pattern as well as method of criticalsequencing followed for the computation of design stormpatterns. Earlier estimates for the peak and time to peakhydrograph was 9143.74 cumec and 18 hrs. respectively.However, the estimates for the peak characteristics ofdesign flood hydrograph obtained from the GIUH basedapproach are 11870.6 cumec and 19 hrs. respectivelyconsidering the same design storm pattern.     

Coupling GIS with Hydrologic and Hydraulic Flood Modelling

Geographic Information Systems (GIS) have been recognised as a powerful means to integrate and analyse data from various sources in the context of comprehensive floodplain management. As part of this comprehensive approach to floodplain management, it is very important to be able to predict the consequences of different scenarios in terms of flooded areas and associated risk. Hydrologic and hydraulic modelling plays a crucial role and there is much to gain in incorporating these modelling capabilities in GIS. This is still a rather complex task and research is being done on the full integration of these models. Interfacing between these models and GIS may be a very efficient way of overcoming the difficulties and getting very good results in terms of engineering practice. This paper presents results based on the use of Intergraph GIS coupled with Idrisi GIS. Using these two systems substantially increased the flexibility of using GIS as a tool for flood studies. A lumped (XSRAIN) and a distributed (OMEGA) hydrologic models were used to simulate flood hydrographs. The well known HEC-2 Hydraulic model was used to compute flooded areas. These models were applied in the Livramento catchment with very good results. The computation of flooded areas for different flood scenarios, and its representation in GIS, can be used in the assessment of affected property and associated damages. This is a very useful GIS-based approach to floodplain management.     

遗传算法在潜水含水层底高分布确定及参数识别中的应用

笔者提出了给定若干个地下水位观测值,利用遗传算法反求潜水含水层底高及含水层渗透系数及饱和度的识别方法。通过二维潜水含水层地下水的流动计算验证了该方法的有效性。     

水力学方法估算大桥对河道防洪的影响

 提出了估算大桥对河道防洪影响的水力学方法，采用这一方法，可以在河道地形和水文资料缺乏的情况下，估算出中、小型河道建桥后桥址上游水位壅高值和壅水范围。具体水力学方法包括：断面流量模数法、宽顶堰淹没出流法、局部水头损失法和恒定渐变流法。应用这些方法，成功地进行了洪湖市汉洪公路新滩东荆河大桥对桥址上游河道防洪影响的计算分析。     

On the Estimation of Phreatic Aquifer Parameters by the Tidal Response Technique

This paper focuses on the effects of tidal fluctuations on groundwater in the Konan groundwater basin of Japan and the methodology for estimating aquifer parameters by the tidal response technique. The field investigation revealed that the twowells (H-5 and I-2) near the coastline are significantly affectedby seawater intrusion, and the water quality is not suitable for most beneficial uses. The tidal cycle further aggravates the groundwater contamination by seawater intrusion into the basin. Using the tidal response model, the aquifer hydraulic conductivity(K) at these two sites is estimated to be 4.5 × 10^-3 and 5.1 × 10^-3 m s^-1, respectively. It was also indicated by the inverse modeling that the tidal fluctuations affect the study area up to about 1 km from the coastline. Further, the tidal efficiency was determined in the range of 20 to 21% at Site I-2 and 38 to 41% at Site H-5. The estimates of the storage coefficient (S) based on the time lag equation were not found reliable for the phreatic aquifer. However, the tidal efficiency-factor equation yielded reliable S estimates in this study. Finally, it is concluded that the tidal response techniqueis effective and reliable for estimating aquifer parameters in the coastal region, and that the Konan basin must be managed judiciously to ensure sustainable utilization of its vital groundwater resources.     

Approximate Methods for the Estimation of Muskingum Flood Routing Parameters

There are a variety of techniques for estimating the parameters x and K of the Muskingum method of flood routing. One common difficulty in all the approaches is that different storm sequences along the same river reach would typically yield different parameter estimates. The a statistical analysis of these parameters also shows that they are highly variable. As a result achieving of a high level accuracy may not be the principle issue in describing x and K. This paper presents two approximate methods for estimating these parameters rather easily. The first method requires the computation of the slopes of the inflow and outflow hydrographs at their point of intersection, and the computation of the maximum storage within the reach. The second method requires the computation of the inflow and outflow hydrographs at two specific points. Three case studies investigated show that the first method gives estimates for the Muskingum parameters comparable to those derived by traditional estimation procedures for hydrographs showing linear characteristics.     

从控制洪水向管理洪水转变的经济学思考

对我国的洪水管理实践进行初步概括和总结,描述了洪水管理的内涵,并从经济学角度分析了洪水管理的目标和其存在的问题;提出从控制洪水向管理洪水、经营洪水转变,进而实现资源化洪水的综合利用,以最大限度地提高水资源利用效率。     

雨量插值方法对BTOPMC模型及洪水模拟的影响

以BTOPMC为研究对象和平台,用最邻近插值法、算术平均法、引入面积权重的泰森多边形法、引入泰森多边形的距离反比加权法4种不同的降雨空间插值方法,对3个小流域进行了洪水模拟,分析了各插值方法对模型参数、模拟精度、洪水洪峰流量、峰现时间等的影响。结果表明:引入泰森多边形的距离反比加权法在各插值方法中表现较好,对各流域各场洪水洪峰流量的模拟精度较高,模拟洪峰时刻与其他几种方法相比更接近实测洪峰时刻;BTOPMC模型原有的最邻近插值法在对模型参数进行率定时Nash效率较高,但在验证时比另外3种插值方法低;引入面积权重的泰森多边形法在模拟中表现不稳定。     

沧河渠道倒虹吸工程行洪口门宽度试验研究

在宽浅式河道上修建穿河倒虹吸工程，行洪口门宽度是影响建筑物投资和安全的决定因素。结合沧河渠道倒虹的工程情况，在数值计算基础上，运用河工模型试验，对穿河工程附近河道的壅水和冲刷进行研究，采用670m口门宽度方案。对同类工程设计具有一定的参考价值。     

石门坎水电站拱坝泄洪消能水工模型试验研究

为了弄清石门坎水电站拱坝泄洪消能的能力,通过拱坝泄流能力水工模型试验,分别模拟3个表孔和两个中孔单独或表孔、中孔联合运用条件下泄流能力、出口流速、压力分布及消能冲刷情况。以验证原设计方案中表孔、中孔体型设计是否合理,从而最终确定表孔、中孔的设计体型。模拟泄洪过程中消力池底板的受力情况变化,根据受力情况提出改善措施,防止发生揭底破坏。对泄洪的雾化问题进行简单分析,提出意见。