基于经验公式建立的滑坡泥石流坝溃口形式预测模型

为了预测滑坡泥石流坝溃决产生的洪峰流量和最大水深,本文的目标是建立滑坡泥石流坝在自然条件下首次溃决形式的经验公式模型,包括平均宽度bc和残留高Hd两个溃口形式的特征参数,从而为制订防灾减灾方案或应急预案提供科学依据。通过野外考察采集的数据以及溃决特征分析,选取影响滑坡泥石流坝溃口形式的主要因子,分别建立了坝高H、有效坝长B、堰塞湖库容W、坝体鞍部单宽体积V、内摩擦系数tan 以及上限粒径d90共6个因子与溃口形式（即溃口的平均宽度bc和残留高Hd）之间的经验关系公式。最后,将经验预测公式运用到实例进行检验,误差较小。     

Efficiency of sediment transport by flood and its control in the Lower Yellow River

This paper presents the characteristics of sediment transport by flood in the Lower Yellow River with the reach from Huayuankou to Gaocun, which is regarded as a typical braided pattern. The Artificial Neural Network Model on Water Use for Sediment Transport (WUST) by flood was established based on the measured data from 1980 to 1998. Consequently, simulations of controlling process of sediment transport by flood were made in terms of the control theory under different scenarios. According to the situation of sediment transport by flood in the Lower Yellow River, Open-Loop control system and feedback control system were adopted in system design. In the Open-Loop control system, numerical simulations were made to reveal the relationship between average discharge of flood and the WUST with varying sediment concentrations. The results demonstrate that sediment concentration has significant influence on the controlling process of flood flow to WUST. It is practical and efficient to control WUST if sediment concentration is less than 20 kg/m³. In the feedback control system, controlling processes of sediment concentration and flood discharge for sediment transport were simulated respectively under given conditions, and it was found that sediment transport process could be controlled completely by sediment concentration and discharge at the inlet of the reach from Huayuankou to Gaocun. Using the same method, controlling processes of sediment transport by flood in other reaches in the Lower Yellow River were also simulated. For the case of sediment concentration being 20 kg/m³, the optimized controlling discharge ranges from 2390 to 2900 m³/s in the lower reach of Huayuankou. This study is also of significance to flood control and flushing sediment in the Lower Yellow River with proper operation modes of Xiaolangdi Reservoir.     

Research on the conversion relationships between the river and groundwater in the Yellow River drainage area

Conversion relationships between the river and groundwater in the Yellow River drainage area are studied in this paper based on the geologic and physiognomy conditions and the data of the groundwater regime, isotope, groundwater flow field and field survey. Then eight recharge and discharge modes on the relationships are put forward and the hydraulic characteristics of the modes are analysed, which provides a scientific basis for quantitatively simulating and assessing the conversion relationships, maintenance mechanism of the Yellow River and the regeneration ability of the groundwater in the area.     

Efficiency of sediment transport by flood and its control in the Lower Yellow River

1IntroductionIntheriversystemwithsediment-ladenflow,WaterUseforSedimentTransport(WUST)isaveryimportantcomponentofecologicalwaterdemands,whichmaintainfundamentalfunctionofallecosystemcomponentsataspecificlevelofcondition[1].EnoughWUSTisthepremisetokeepthestableriver-bedandhealthyriverecosystem;alsoitisthebaseflowofriverfortheexploitationofwaterresources.Comparingwithotherrespectsrelatedwithwaterdemandsofriverecosystemsuchastheminimumflowforfishesorripariantrees,researchesontheWUSTarequite…     

Research on the conversion relationships between the river and groundwater in the Yellow River drainage area

InthevastdrainageareaoftheYellowRiver,thereexistsaclosehydraulicrelationandfrequentconversionbetweenthestreamandthegroundwater.However,inrecentyears,duetotheintensifiedhumanactivitiesandtheminifiedriveroutflow,thestrengthenedconversionrelationshipbetweentheriverandthegroundwaterresultedinthechangeofthewatercirculation,andprovokedaseriesofsideeffectsontheecologi-calenvironmentintheareaandmadethewaterresourceandecologyintheYellowRiverdrainageareaamatterofgreaturgency.TheissuesontheYellowRivera…     

黄河大堤河南段历史文化资源的类别与特征研究

黄河是中华民族的母亲河,更是一条文化河流,黄河两岸在千百年来孕育了许多的优秀文化。黄河干流的中下游河南段在历史上决口最多、改道最明显,黄河大堤成为人们战胜灾难、征服自然的工程奇迹。从历史文化的角度,对黄河大堤历史文化资源的类型和特征进行了分析,以期为更好地保护黄河大堤,发挥黄河大堤的文化历史遗产作用提供参考。     

一维洪水演进数学模型研究及应用

从求解一维对流方程的Holly-Preissmann格式出发,结合有限差分法建立了一维洪水演进数学模型.并根据实验室溃坝实验结果与溃坝理论解对新建模型的计算精度进行了分析,模型计算结果与实验结果及溃坝理论解均十分吻合,表明模型具有相当高的计算精度.最后将模型应用于长江荆江河段洪水演进计算,取得了较好的结果.     

史前郑州地区黄河河流地貌与新构造活动关系初探

虽然历史时期黄河在郑州地区与桃花峪冲积扇上的变迁已有较为系统的研究,但是由于上古文字资料的欠缺,相关研究的不足,关于史前时期黄河在大郑州地区的河流地貌特征、河道在黄河下游冲积扇上部演变的论述甚少,认识还非常粗浅.文中试就黄河下游演变意义上至关重要的郑州大区和史前黄河在桃花峪以上特定地域的河流地貌、河道演变与新构造活动的某些关联问题以及郑州西部构造地貌对于河湖水系演化的作用提出一些看法.     

新疆克孜河泥石流天然坝体溃决模拟分析

分别采用瞬时溃决模型和逐步溃决模型对新疆克孜河泥石流天然坝的溃决洪峰流量及其向下游的演进情况进行了模拟分析,结果表明：瞬时渍决模型的计算结果与实测溃坝洪峰流量偏差较大,而逐步溃决模型的计算结果则接近实测值;采用逐步溃决模型计算时,计算时段的取值及溃口流量系数的取值对计算结果有一定的影响．     

Modeling sediment transport in the lower Yellow River and dynamic equilibrium threshold value

1IntroductionTheYellowRiverbasin,knownasthecradleoftheChineseculture,hasalargepopulationandisrichinnaturalresources.ThisregionanditseconomicconditionshavebeenimprovedquicklysinceChina’seconomicreformandopening-up.However,thewaterresourcesandtheirenvironmentalissueshavereceivedlittleattention.Thesedi-mentconcentrationintheYellowRiverissohighthatthedepositionontheriverbedmakestheriverbedelevationhigherthanthegroundoutsidetheriverbanks,whichleadstothefamous“suspendedriver”sceneintheregion.P…     

Modeling sediment transport in the lower Yellow River and dynamic equilibrium threshold value

A major problem in the lower Yellow River is the insufficient incoming water and excessive sediment supply, which results in serious deposition, continuous rise of the river bed, and austere flood control situation. To understand the sediment transport regularity of the lower Yellow River and determine the relationship between sedimentation, incoming water and sediment, and zone water diversion, a mathematical model of the sediment suitable for the characteristics of the lower Yellow River has been developed. This model is first rated and verified by large quantity of observed data, and it is then used to analyze silting reduction for the lower Yellow River by Xiaolangdi Reservoir’s operation, the relationship between zone water diversion and channel sedimentation, and critical equilibrium of sedimentation in the lower Yellow River. The threshold values of equilibrium of sedimentation in the lower Yellow River are estimated and they suggest that deposition in the lower Yellow River can be effectively reduced by the operation of regulating flow and sediment from Xiaolangdi Reservoir, water-soil conservation, and controlling water diversion along the lower Yellow River.     

堰塞体状态相关剪胀理论与坝体溃决演化规律研究构想（特约稿）

堰塞体一般在自然力作用下瞬间形成,堆积体具有空间结构复杂、坝料级配宽泛、稳定性差、易在水流冲刷下发生溃决等特点。堰塞体作为一种重大的水旱自然灾害,其安全评价和灾害预测是国内外学者关注的焦点,目前尚有很多问题需要解决,包括：（1）堆积体由天然宽级配土石料构成,表现出显著的状态相关性,缺乏正确描述这种宽级配堆石料的状态相关剪胀理论与本构模型;（2）堰塞体形成后,会受上游堰塞湖水位抬升、持续非稳定渗流、湖区滑坡涌浪、后期地震等外荷载作用的影响,缺乏稳定性评判的标准和方法;（3）堰塞体缺乏必要的洪水溢流设施,容易发生溃决,且溃决水流冲蚀过程呈明显的非线性特点,溃口水力要素指标呈强非恒定流特征,缺乏反映宽级配堰塞体材料冲蚀机理的溃决过程数学模型。为此,有必要采取现场勘查、多尺度物理模型试验、数值仿真等综合手段开展研究,揭示堰塞体外观形态、内部结构和材料宏观力学特性及其时空变异规律,提出状态相关（级配、孔隙比、应力水平）的宽级配堰塞体材料剪胀方程,建立能适应复杂应力路径的广义弹塑性本构模型与坝体极限平衡分析方法;开展大型水工模型试验和溃坝离心模型试验研究,揭示非恒定流作用下堰塞体材料的动态冲蚀特性与堰塞体溃口演化规律,建立非恒定流作用时溃口动边界条件下的挟砂水流冲蚀方程,提出考虑流固耦合的堰塞体溃决过程数学模型,实现堰塞体漫顶或渗透破坏溃坝全过程水流运动特征、坝料输移规律、溃口演化过程及结构失稳的数值模拟。综合可靠度理论与溃坝过程数值模拟方法,提出能考虑流固耦合的堰塞体渗流、变形、稳定和溃决过程的一体化数值仿真平台,构建堰塞体全生命周期安全评价与灾变模拟理论体系与方法,为提升我国堰塞体防灾减灾决策水平提供科学的理论与技术支撑。     

黄河下游河段渗漏耗水量时空变化分析

针对黄河下游"地上悬河"的特殊地貌状况,采用试验观测与数学建模相结合的方法,分析了黄河下游河道渗漏耗水量的变化.利用竖管法现场测定河床沉积物的渗透系数,根据黄河下游各水文站1991—2005年的月、年水位资料及相应年份两岸距离黄河最近的地下水长观孔的月、年资料,以达西定律为基本数学模型,通过物理试验确定参数,分析计算了各子河段的等效渗透系数和各子河段的其他信息,计算了黄河下游河道1991—2005年的渗漏耗水量,并分析其时空变化特征,为黄河下游水量统一调度提供技术支撑.     

无粘性土堤漫顶溃决溃口区域水力参数变化过程数模研究

结合物理模型试验建立平面二维水流数学模型,采用高分辨率有限体积格式计算漫顶溃堤洪水演进过程,并针对不同时段溃口形态建立三维几何模型进行水力参数变化规律数值模拟.研究结果发现,堤防溃决属溯源冲刷,与流速密切相关;溃决过程外江水位平稳下降,内江水位先上升后逐渐稳定,内外江水位差随溃口展宽逐渐减小;壁面剪切应力及动水压力较大区域集中在溃口内江侧与河底连接处,且随溃决过程逐渐减小.     

台风暴雨影响区溃坝洪灾淹没损失评估

东南沿海地区受台风暴雨影响易发生山洪、诱发水库溃坝,且水库下游区域往往地势低洼开阔,易积水而出现大面积内涝,对溃坝洪水演进产生一定影响.采用能够考虑下游初始淹没水深的二维洪水演进模型计算溃坝洪水过程,阐述了溃坝洪水数值计算方法、洪水淹没损失分类及损失率确定方法,建立溃坝洪灾淹没损失评估模型.以戍浦江流域为例,确定溃坝洪灾损失率与淹没水深等级关系,对淹没区进行溃坝洪灾淹没损失评估.计算结果表明：水库一旦发生溃坝,洪灾将造成83亿元经济损失,下游社会和生态环境遭到严重破坏,采取有效的预警措施能够显著减少下游的人员伤亡及经济损失.通过溃坝灾害评估,有助于提高水库安全管理水平,为制定防洪避险预案提供支持.     

基于季节性AR（P）模型的水质预测

自回归模型的建立是基于序列平稳性的假设,只能描述平稳序列的统计特性,而水质的月监测数据序列往往具有季节性变化的现象。文章介绍了平稳过程的相关理论及其检验方法并应用到黄河潼关、三门峡断面的水质序列的检验中,检验结果为非平稳序列,且序列具有明显季节性（月份）变化的特性。为此尝试建立季节性AR（P）模型来捕捉黄河水质的季节性变化规律,实践表明该模型预测总体效果是较为满意的。     

二维浅水间断流动数值模型在涌潮模拟中的应用

为模拟涌潮、水跃、溃坝波、浅水变形后的波浪、闸门突然开启形成的涌浪等浅水间断流动,应用有限体积法求解二维浅水方程,界面通量采用基于Boltzmann模型的动力学流矢量分裂（KFVS）格式,建立基于无结构三角形网格的二维浅水间断流动数值模型,模型在空间上具有二阶精度.在钱塘江两次涌潮实测资料验证的基础上,模型预测了钱塘江河口治理设想方案实施后的潮位、潮差、流速和涌潮等水动力因素的变化.模型较好地模拟了涌潮到达时刻潮位急剧抬高、流速迅速从落潮转为涨潮并达到极值的间断现象.计算结果表明,提出的计算格式健全、稳定,可以广泛应用于浅水间断流动的数值模拟.     

基于生命旋回-权马尔可夫的径流预测模型

针对生命旋回预测模型不能反映河川径流周期性和波动性变化的特点,将其与权马尔可夫链结合,提出了一种精度较高的预报模型——生命旋回-权马尔可夫链组合模型.该模型用生命旋回模型预报河川径流的趋势项变化,由权马尔可夫链对径流残差序列进行修正,进行预测时采用等维信息方法处理,在此基础上对黄河龙门水文站径流进行预测,拟合精度为86.97%,合格率为86.78%,表明该模型可以用于径流预测.此外,对求解生命旋回模型的方法作出了改进,经研究表明,该方法实用可行.     

黄河流域城市群城镇化与生态环境耦合协调预测

城镇化对于生态环境的胁迫效应和生态环境对城镇化进程形成的约束作用具有积累性和长期性。针对基于历史数据分析中未考虑到的滞后性问题,以黄河流域呼包鄂榆、宁夏沿黄、兰西、关中平原、中原、山东半岛和晋中等7个城市群为基本研究单元,构建城镇化与生态环境评价指标体系和耦合协调度模型,对2000～2019年黄河流域城市群耦合协调度进行测度,并建立ARIMA-BP组合模型来预测2020～2025年未来发展趋势。结果表明:黄河流域城市群耦合协调度呈上升趋势,部分城市群出现波动,耦合协调特征由轻度失调、濒临失调转为勉强协调、初级协调; 对未来6年耦合协调度预测发现,7个城市群耦合协调度未来皆表现出上升趋势,但不同城市群存在一定差异,部分城市群在2025年依旧未能突破轻度协调达到更加理想的耦合协调阶段。未来应不断提升山东半岛城市群核心竞争力,推进关中平原城市群和中原城市群次级中小城市成长壮大,并且要格外关注呼包鄂榆城市群、晋中城市群依靠资源发展所导致的水土流失和污染防治问题,加强宁夏沿黄城市群和兰西城市群城镇化建设和生态环境保护力度,补齐流域发展短板,早日实现流域城市群协同发展。     

黄河泥沙数学模型研究

介绍了适合于黄河中下游水库、河道的泥沙冲淤一维数学模型．该模型在断面概化、含沙量及冲淤量横向分布计算和非均匀沙计算等方面采取了新的处理办法．