1950—2010年黄河径流情势变化特点

对1950—2010年黄河径流地区分布不均匀、断流和连续枯水段历时较长等特点进行了分析,阐述了天气变化、植被变化、水利工程对径流的调节、工农业及生活用水等影响黄河径流变化的因素,提出了相关建议:①长期推行节水和水土保持建设;②建立流域机构统一管理与省(区)水行政主管部门分级管理相结合的黄河水资源管理体系;③积极推进补水工程建设;④建立污染物入河总量控制、排污入河许可等水资源保护制度,提升对污染物输移扩散的预测预报水平与能力。     

Identification of relationship between sunspots and natural runoff in the Yellow River based on discrete wavelet analysis

Annual natural runoff is an important index of a river, which may be affected by solar activities. In this study, 304 years of annual natural runoff at the Sanmenxia station located in the Yellow River and the sunspot relative number are decomposed with the application of a Complex Morlet. According to the results of real part, modulus and second power of modulus, the annual runoff series at the Sanmenxia station has an obvious periodic oscillation on 90–100, 50–80, 35–50, 15–35, about 10, and less than 10-year scales. Also, there are obvious periodic variability with 60–90 years, 30–50 years and about 10 years. There are two centers of energy: one is about 1840–1850 on 7–11-year scale and the other is about 1825–1925 on 60–70-year scale. From the wavelet variance, 3, 26, 46, 68 year periods are detected within a 100-year scale, and the 68-year period is the most significant. Similar analyses are conducted for the sunspot relative number within the same period 1700–2003. The sunspot series shows 11- and 60-year period variation, as well as eight energy centers. Then, the correlation analyses for 11- and 60-year serial scales are computed. From a long-term period (1700–2003) view, there is no notable correlation between the natural runoff and the sunspot relative number; however, it is evident that the correlations exist within a short-term period. The results also indicate that the relationships between solar activities and the natural runoff in the Yellow River are complicated.     

DLL?技术在水文预报系统中的应用

在水文预报系统开发中,通过 DLL 技术的应用,既充分发挥多种开发语言各自的特长,提高系统开发效率,又可提高系统的运行速率,增强系统的可扩展性.详细分析用 VB 创建及测试水文预报模型.DLL 的步骤,以及在 ASP.Net 中如何调用 VB 创建的 DLL 进行水文预报.程序编写和调用实例证明,使用 DLL 技术实现水文预报的方法是切实有效的     

少资料条件河渠冬季冰情过程模拟研究

针对天然河道开展冰情过程数值模拟普遍存在的河道断面资料、水文和气象资料缺少的难题,本研究提出了时均气温和时均太阳辐射计算方法和支流流量的动态分配方法,即根据实测日最大气温、日最小气温和日净太阳辐射率定出关键影响参数,模拟出给定气象站的时均气温和时均太阳辐射的变化过程;通过上游流量向下游传播过程的特征分析,推演出缺少支流...     

云南2009—2014年持续性气象水文干旱特征及成因分析

基于戴-帕尔默干旱强度指数(Dai Palmer drought severity index,Dai-PDSI)和径流干旱指数(streamflow drought index,SDI),分析云南地区2009—2014年持续性气象干旱与水文干旱时空演变特征,并利用NCAR/NCEP再分析资料,从西太平洋副热带高压、青藏高压、南支槽、对流层垂直运动及水汽垂直分布等视角,分析2009—2014年云南持续性干旱的原因。结果表明:(1)2009—2014年是云南地区自1961年以来最严重的一次持续性极端干旱过程,2009年10月—2010年9月是最干旱的时段;夏季与冬季是干旱最严重的两个季节。(2)在空间上,云南中东部旱情最重,东南部稍轻。(3)水文干旱伴随气象干旱而生,金沙江和南盘江出现重度水文干旱,澜沧江出现中等水文干旱,从强度上讲,水文干旱弱于气象干旱。(4)夏季西太平洋副热带高压偏西偏强,青藏高压持续偏强、中心偏西,云南上空的大气持续受它们控制,盛行下沉气流;冬季南支槽偏弱,不利于引导孟加拉湾水汽北上;在其他季节,大气多以下沉运动为主,对流层水汽严重不足。     

基于等效原理的水库群实时防洪联合调度模型研究

针对水库群规模大导致水库群联合调度模型求解困难、交互决策难以聚焦的问题,提出了基于等效原理减少联合调度模型水库数的新思路,即将水库群全集划分为显效水库和非显效水库子集,对显效水库开展联合补偿调度,非显效水库作为被补偿对象单库调度;并建立水库群分组指标体系和分组方法,由此构建了显效水库联合调度和非显效水库单独调度的混合调...     

马斯京根法在黄河吴堡—龙门区间洪水演算中的应用

针对黄河吴堡龙门区间(吴龙区间)洪水陡涨陡落的洪水特性和多支流的水系特点,采用马斯京根分段连续演算法模拟黄河吴龙区间洪水过程,建立了基于先合后演法的洪水演算方案,给出了分段初始流量确定方法,并制定了支流洪水处理方案,采用实测期与预报期实测洪水资料率定和检验参数,结果表明洪水模拟精度较高。     

主成分分析法在黄河三门峡库区水质评价中的应用

借助SPSS软件,根据主成分分析法的原理,以多年的监测资料为依据,对三门峡库区干流段的污染情况进行了评价.结果表明,在汛期和非汛期,接受评价的4个断面中,有机物和重金属是污染的主要因素,4个断面在不同时段污染程度有差别.得到的结果与实际情况相符,表明主成分分析方法简单、明了,是比较实用的水质评价方法.     

黄河内蒙古河段典型凌情过程模拟

近十几年受人类活动和气候变化等影响,黄河内蒙古河段冰情出现新的特征,突发凌情频繁出现,原有的内蒙古河段冰模拟方法已不能满足当前凌情防治的需要,亟待建立能反映凌情物理特性变化规律的河段冰情动态发展数学模型。在实测资料基础上,研究了黄河内蒙古河段冰情时空变化规律,以及河道资料不完整、支流流量资料缺乏及冰桥位置的确定等问题。应用一维冰情数学模型模拟2012—2013年凌汛期黄河内蒙古河段冰情发展过程,并对水温、冰盖厚度、冰盖前沿发展和流量的模拟值和实测值进行了对比分析,模拟值和实测值吻合较好。本研究为黄河防凌提供科学依据和方法支撑,也为天然江河、人工渠道冰情全过程模拟提供了研究思路和技术手段。     

An efficient dynamic uniform Cartesian grid system for inundation modeling

A dynamic uniform Cartesian grid system was developed in order to reduce the computational time in inundation simulation using a Godunov-type finite volume scheme. The reduction is achieved by excluding redundant dry cells, which cannot be effectively avoided with a conventional Cartesian uniform grid system, as the wet area is unknown before computation. The new grid system expands dynamically with wetting, through addition of new cells according to moving wet-dry fronts. The new grid system is straightforward in implementation. Its application in a field-scale flood simulation shows that the new grid system is able to produce the same results as the conventional grid, but the computational efficiency is fairly improved.