浅谈灰色系统理论在旱涝预测中的应用

对灰色系统理论进行简单介绍，着重于灰色系统理论中灾变预测的建模过程，并以实例说明如何在水文长期预报中应用灰色灾变理论。     

一种适用于灰色预测控制的无偏直接GM（1，1）模型

GM（1，1）模型是灰色预测控制器的重要组成部分，它是有偏差的模型．提出了一个无偏差的模型一无偏直接GM（1，1）模型，结合具体数据将无偏直接GM（1，1）模型和GM（1，1）模型进行了比较，结果表明无偏直接GM（1，1）模型优于GM（1，1）模型．将无偏直接GM（1，1）模型替代GM（1，1）模型应用于灰色预测控制中可望得到较好结果．     

灰色残差模型与递补模型对比及在城市需水量预测中的应用

在传统灰色预测基础上,通过模型模拟的还原值与原始数据比较,取其差值,构建新数列模型代回原模型修正误差。灰色残差模型在模拟精度方面超过传统灰色方法,而且更能对外界因素的影响做出反应。通过对比和实践验证,灰色残差模型和递补模型都很好地弥补传统灰色模型的不足而且能更好地预测城市未来需水量。     

基于灰色GM(1,1)模型的农业用水量预测

介绍灰色理论建模原理和模型参数辨识方法,并以实例(阿克苏地区1995~2005年农业用水资料)建立灰色GM(1,1)预测模型,运用残差检验、后验差检验以及关联度检验3种方法对模型进行精度检验,其模型拟合精度达98.31%。用所建立的模型对阿克苏地区2006~2010年农业用水量进行外推预测,结果表明:该灰色模型用于农业用水量预测,符合其灰色特性,通用性好,并且所需数据少,计算量适中,预测结果与当地实际情况比较吻合。     

GPSIM(1)模型在预测地表水COD_(Mn)指数中的应用

由于常规GM（1，1）有许多不足，因而限制了它在环境科学领域中的应用范围。本文采用较新颖的GPSM（1）灰色模型，作为某水域地表水CODmn指数时序资料的预测模型。应用表明，GPSM（1）模型较GM（1，1）具有更高的拟合、预测精度。     

灰色GM（1,1）模型误差特性的实验研究

从理论上分析了影响灰色ＧＭ（１，１）模型精度的三个主要因素，通过实验的方法研究了各个因素对模型误差特性的影响，并作出了用指数序列建模时的误差特性曲线。实验的结果有助于人们对ＧＭ（１，１）模型的认识和应用。     

灰色模型在广州年需水量预测中的应用

灰色模型用于城市年需水量的预测，能够克服传统的数理统计方法的资料难以收集、精度难以保证等不足。该文结合广州市2003～2010年的年用水量建立GM（1，1）模型进行拟合，结果良好。对2011～2015年广州市需水量进行预测，发现2011～2015年广州市需水量总体呈现下降趋势，其中工农业需水量下降趋势明显，但生活需水量呈现增长趋势。     

GM(1,1)等维新息模型在土石坝沉降预测中的应用

采用灰色等维新息模型模拟土石坝的时效变形，预测了土石坝时效位移的未来变化趋势，并结合陆浑水库大坝实测资料编制了计算程序，同时对等维新息模型的最佳数区进行了讨论，得到了具有实用价值的结论。     

填海造地道路软基沉降的不同数据序列GM（1，1）预测模型

为了研究不同样本数据序列GM（1,1）灰色模型在填海造地道路软基沉降预测中的实用性和有效性。结合工程实例,以软基沉降监测数据为依据,分别选取堆载预压恒载期的10组和20组实测地基沉降数据作为样本数据序列,建立了相应的GM（1,1）灰色预测模型,对软土地基固结沉降进行了预测,并将两种不同数据序列灰色模型预测结果与现场实测数据进行了对比分析。研究结果表明：GM（1,1）灰色模型所得预测曲线与实测曲线变化趋势基本一致,预测值与实测值吻合较好,实测曲线比预测曲线收敛较快,较多样本数据序列灰色模型所得预测精度更高。     

乾安县地下水氟含量评价与预测

乾安县地下水氟含量评价与预测乾安县水利局水资办王永成，王奇杰，董志内容提要：地下水中的氟含量过高或过低，都会引起慢性氟中毒。为防止地下水中氟对人体的危害，就要对氟离子的分布规律作出评价和预测。本文以乾安县为例，运用灰色统计方法和灰色ＧＭ（１、１）模型...     

生物絮凝泥沙运动输移数学模型

近几十年来,河流中生物絮凝泥沙的运动输移对河流生态系统与水工建筑物等造成的影响,已逐渐成为一个研究热点。本文将泥沙运动输移模型与生物絮凝机理模型耦合起来,构建生物絮凝泥沙运动输移数学模型,以预测富营养水生态系统中生物絮凝泥沙运动输移过程中的浓度及水位变化。模型中,通过求解一维非恒定流圣维南方程来计算水流,将生物絮凝视为导致悬浮泥沙絮团粒径变化的主要因素,通过不饱和非均匀输沙(泥沙/絮团)方法来模拟生物絮凝泥沙的运动。利用文献数据和室内水槽实验来验证生物絮凝泥沙运动输移数学模型,模拟结果与实验数据吻合较好,表明所构建的一维数学模型可以较好地模拟生物絮凝泥沙的输移特性。     

黏性泥沙不等速沉降絮凝的格子Boltzmann模拟

建立黏性泥沙运动的三维格子Boltzmann模型,对黏性泥沙不等速沉降絮凝过程进行全尺度直接数值模拟,从微观角度分析了泥沙颗粒不等速沉降形成的絮团特性和絮团成长过程。模拟结果与已有实验结果一致。模拟结果还表明,不等速沉降时不同泥沙浓度条件下形成的絮团若大小相近则沉降速度接近,但泥沙浓度对水体中泥沙总体平均沉速有明显影响,泥沙浓度越高,泥沙平均沉速越大,主要是因为泥沙浓度越大,颗粒之间越容易发生碰撞而形成更大、更多的絮团。     

泥沙模型时间变态影响消减措施探讨

针对长江中下游河段泥沙模型时间变态影响及其消减措施的问题,通过回顾以往相关研究工作,分析了时间变态成因及其影响,并评述了消除或减弱泥沙模型时间变态影响的有关措施或设想。在此基础上,以长江南京河段泥沙模型为实例,基于调整模型水沙过程概化方式的思路,进行了消减时间变态影响的试验研究。结果表明:按水沙过程逐日平均概化方式进行泥沙试验基本可行,有望在长河段模型试验中解决或改善时间变态所带来的涨水水量不足和落水水量排除的难题。     

Numerical and experimental study of continuous and discontinuous turbidity currents on a flat slope

When the sediment and the dissolved matter laden in the river meet a clear water in reservoirs, the turbid water will plunge and spread into the clear water, forming the turbidity current and influencing the water quality and the life of the reservoir. Due to the unsteady nature of the flood, the turbidity current is unsteady. In the present study, we use the MIKE 3 computational fluid dynamics code to simulate continuous and discontinuous turbidity currents on a flat slope. With the model used by us, the turbulence is divided into two parts: the horizontal turbulence and the vertical turbulence, which are separately modeled by the Smagorinsky model and our model to capture the anisotropic turbulence. In this model, the sediment settling and deposition are considered. The simulation results concerning the flume water surface level, the front velocity and sediment concentration profiles are found consistent with the experimental data, particularly, for the sediment concentration profiles with an absolute mean error of 0.026 kg/m~3 and the root mean square error of 0.046 kg/m~3. This finding suggests that this model can be used to well predict the turbidity current on the flat slope.     

Combination of Runoff Simulation with Sediment Modeling in Rivers and Its Application in the Lower Yellow River

Abstract

Previous research on runoff show flow and sediment movement in rivers, and river bed variations are usually separated. This paper, from the point of view of the basin as a whole system, presents an integrated approach by combining runoff simulation with numerical model of sediment transport in rivers to simulate the whole processes of hydrological variables and flow-caused bed variations from the very upper part of the basin to the river mouth. To accomplish this purpose, BTOPMC, a rainfall-runoff model, and NUSTM-1D, a well-developed numerical model for sediment transport and river bed variations, are selected to form a combined model. The application of the proposed model to the lower Yellow River shows that it can properly simulate rainfall-caused runoff, the change of suspended sediment concentration along the river, and river bed variation.     

排沙漏斗悬移质泥沙运动数值模拟

排沙漏斗是一种利用立轴旋涡实现水沙分离的二级排沙设施。为了探明排沙漏斗悬移质泥沙运动特征和排沙机理,采用欧拉-拉格朗日方法模拟了排沙漏斗水气沙三相流动,其中水相和气相采用雷诺应力模型(RSM)和VOF方法描述,悬移质泥沙用颗粒轨道模型描述。通过对计算的悬移质含沙量垂向分布与实验结果的对比,验证了数学模型的可靠性。计算结果表明:在漏斗室外侧区域含沙量分布整体上较均匀,在漏斗室内侧区域的近底部存在一个明显的高浓度带。作者认为,上述排沙漏斗悬移质泥沙含沙量分布特征主要是由排沙漏斗内的二次流引起的。     

泥沙不同起动模式的起动概率对比分析

基于颗粒间相对暴露度的分布规律,确定了河床近底水流流速有效作用点高度yb和近底时均流速。在此基础上,分别比较了滚动模式、滑动模式和跃移模式下泥沙临界起动平衡条件,推导出了三种起动模式下的起动概率。经分析发现:在床面泥沙颗粒处于相对暴露度均值为0.16状态下及同样的水流条件下,泥沙滑动模式和滚动模式起动概率处于同一量级,滑动模式更容易起动,跃移模式最难起动;当水流强度较小时,泥沙颗粒以滚动(间或滑动)模式起动为主,反之,以跃移模式起动为主。     

杭州湾口悬沙浓度变化与模拟

本文对杭州湾口 1 5个测站的大、中、小潮悬沙浓度的变化规律进行了分析 ,得出大 -小潮周期流速变化和水位变化是该海区各站悬沙浓度变化的主要影响因素。通过分析研究 ,建立了单点测站悬沙浓度变化与水位和大 -小潮最大流速的关系模型 ,用该模型的计算结果与实测资料进行比较 ,拟合程度较好 ,对于整个大 -小潮周期悬沙浓度的连续变化可采用该模型进行估算。     

The assessment of suspended sediment inputs to Volta Lake

Information on a river basin's sediment yield is an important requirement for water resources development and management. In the Volta River basin of Ghana, data on suspended sediment yield are limited due to the lack of logistic support for systematic sediment sampling activities. This paper presents the results of a study using the available measurements of suspended sediment transport for eight monitoring stations in order to develop a simple predictive tool for estimating the suspended sediment yields for catchments for which no sediment measurements had been undertaken. Regression analysis was used to establish a relationship between specific suspended sediment yield and both the mean annual run‐off and the drainage basin area. The prediction model was used to estimate the sediment loads of the Volta River and its main tributaries (Black Volta, White Volta and Oti Rivers) in order to estimate the total suspended sediment input to the reservoir and the equivalent specific suspended sediment yield from the catchment surface. Although these sediment yield values are relatively low by world standards, the results obtained provide a basis for assessing future sedimentation problems in Lake Volta and for underpinning the development of sediment control and management strategies for the reservoir.     

Modeling of Sediment Yield Prediction Using M5 Model Tree Algorithm and Wavelet Regression

The forecast of the sediment yield generated within a watershed is an important input in the water resources planning and management. The methods for the estimation of sediment yield based on the properties of flow and sediment have limitations attributed to the simplification of important parameters and boundary conditions. Under such circumstances, soft computing approaches have proven to be an efficient tool in modelling the sediment yield. The focus of present study is to deal with the development of decision tree based M5 Model Tree and wavelet regression models for modeling sediment yield in Nagwa watershed in India. A comparison is also performed with the artificial neural network (ANN) model for streamflow forecasting. The root mean square errors (RMSE), Nash-Sutcliff efficiency index (N-S Index), and correlation coefficient (R) statistics are used for the statistical criteria. A comparative evaluation of the performance of M5 Model Tree and wavelet regression versus ANN clearly shows that M5 Model Tree and wavelet regression can prove more useful than ANN models in estimation of sediment yield. Further, M5 model tree offers explicit expressions for use by design engineers.