清流河流域场次暴雨洪水特征及其对降水的响应关系

暴雨洪水是主要的自然灾害,分析暴雨洪水特性及其与气候要素的响应关系对流域防洪减灾和水资源可持续利用等方面具有重要意义。根据清流河流域102场暴雨洪水资料,系统分析了场次暴雨洪水过程特征、径流组成以及洪水特征要素与降水指标之间的响应关系。结果表明:场次降雨特征在一定程度上决定了洪水过程变化,水利工程修建和下垫面变化等人类活动对暴雨洪水过程特征有一定影响;场次暴雨洪水的产流系数总体具有递减趋势,但地表径流占径流总量的比率有增大趋势;场次径流量及洪峰流量与场次降水量之间具有较好的相关性,雨强对清流河流域暴雨洪水特征影响相对较小,蓄满产流是清流河流域主要的产流机制。     

喀斯特地区流域洪水退水过程分析——以贵州省黄洲河流域为例

为研究喀斯特地区流域洪水退水的过程特性,以贵州省黄洲河流域为研究对象,对流域径流进行基流分割,运用指数型退水模型公式对退水过程进行模拟.结果表明:①黄洲河流域洪水过程的总流量变化与基流变化呈现正相关,退水过程受降雨时长、流量大小以及流域岩性特征等因素的影响.②地表径流退水速率大于地下径流退水速率,流域内大量的岩溶孔隙和...     

西北江三角洲场次洪水的退水过程模拟

以珠江流域北江的三水水文站、海丰村水文站,西江的马口水文站3个站点5个洪水场次的水位数据为例,使用不同模型对其退水过程进行模拟分析,结果发现,对于海丰村水文站,可以用多项式模拟其退水过程,三水(二)、马口水文站,可以用正弦曲线模拟其退水过程.退水曲线最优拟合模型可以在洪水退水预报中应用.     

基于HEC-HMS模型的温榆河流域水文模拟

水文模拟对于流域防洪减灾、水资源规划管理有重要的意义。将分布式水文模型HEC-HMS应用到北京温榆河流域,模拟该区域1980-2005年间6场暴雨洪水过程和1983-1995年日降雨径流过程,评估HEC-HMS模型在模拟场次洪水和日径流过程两种时间尺度上的适用性。结果表明,场次洪水模拟的洪峰流量和洪量相对误差均在20%以内,峰现时差均不超过2h,平均Nash效率系数为0.82,平均相关系数r为0.92;日径流模拟率定期和验证期的平均Nash效率系数为0.6,平均相关系数r为0.78,平均相对误差为3.95%。分析结果表明,HEC-HMS模型在温榆河流域的适用性较好,能够有效模拟北方地区短时和长时降雨径流过程,可用于该区域的洪水预报和水资源评价与管理。     

基于 H EC2HM S 模型的温榆河流域水文模拟

水文模拟对于流域防洪减灾、水资源规划管理有重要的意义。将分布式水文模型 HEC2HM S 应用到北京温 榆河流域, 模拟该区域 1980- 2005 年间 6 场暴雨洪水过程和 1983- 1995 年日降雨径流过程, 评估H EC2HM S 模型 在模拟场次洪水和日径流过程两种时间尺度上的适用性。结果表明, 场次洪水模拟的洪峰流量和洪量相对误差均 在 20% 以内, 峰现时差均不超过 2 h, 平均 Nash 效率系数为 01 82, 平均相关系数 r 为 01 92; 日径流模拟率定期和验 证期的平均 Nash 效率系数为 01 6, 平均相关系数 r 为 01 78, 平均相对误差为 31 95 % 。分析结果表明, H EC2H MS 模型在温榆河流域的适用性较好, 能够有效模拟北方地区短时和长时降雨径流过程, 可用于该区域的洪水预报和水 资源评价与管理。     

广州“5.22”暴雨及暴雨洪水量级分析

该文以广州市官湖河为研究对象,采用实测降雨资料及暴雨等值线图进行流域设计暴雨计算,采用小流域暴雨推求设计洪水的方法进行官湖河流域设计洪水的计算分析;通过对“5.22”暴雨期间官湖河流域实测降雨资料进行统计分析,并与流域设计暴雨相对比,得出流域各历时暴雨等级;以流域综合单位线及“5.22”实测降雨过程为基础,用卷积公式计算设计洪水过程线,通过“5.22”场次洪水调查论证暴雨洪水计算成果合理性,并与流域设计洪水相比较,给出“5.22”洪水等级。     

基于试验流域的季风区洪水特性及其水文模拟

根据我国安徽省5个试验流域的实测资料,分析了各流域场次洪水的特性,并利用TOPMODEL模型对各流域进行次洪模拟,进一步探讨该模型在我国东部季风区洪水预报方面的适用性。结果表明:安徽省各试验流域场次洪水的降雨量-径流深散点均呈现较好的正相关性,降雨量随着海拔的升高而增大,山区的径流系数大于平原丘陵区;面积最小的瓦屋刘流域对暴雨的响应最为敏感,孙村流域场次洪水的洪峰模数差异最小、起涨时间最长,黄山流域场次洪水的历时最久;随着海拔的升高,流域地形指数的平均值逐渐增大,同时各流域面积占比最大所对应的地形指数逐渐减小;地形指数标准差越大的流域,土地利用类型也越丰富;TOPMODEL模型总体上可以较好地模拟安徽省各试验流域场次洪水过程,且对大流量的捕捉效果优于小流量,对天然流域的模拟效果优于人类活动扰动的流域。     

一种可以预报洪水过程退水段的程序

本文利用径流过程的灰色模型,建立了洪水过程退水段的预报程序。经实际使用,效果良好,现介绍如下。1.模型简介一次洪水过程,按峰顶可将其划分为涨水段AC和退水段CB,见附图。经研究表明,退水段具有指数曲线规律。     

滁河流域2003年梅雨期暴雨洪水分析

2003年梅雨期滁河发生了特大暴雨洪水，暴雨中心稳定在襄河、清流河和来安河上，滁河流域(六合以上)3d面雨量为有实测记录以来的最大值，致使支流襄河、清流河水位超过历史最高记录，其余干支流洪水位接近历史最高记录。详细分析了“2003、7”暴雨洪水过程，并与1991年滁河暴雨洪水作了对比分析。     

新疆木垒河“07．7”暴雨洪水特点与警示

2007年7月中旬木垒河流域发生了一场有历史资料记录以来的特大洪水,洪峰之高、洪量之大为历史上罕见,通过对该场次暴雨洪水特性进行分析,有助于提高该流域对暴雨洪水灾害性认识.     

Estimating design floods based on the critical storm duration for small watersheds

The objective of this study was to propose a new method to determine design floods using the critical storm duration concept. Five different models, including the Rational, SCS, and Clark methods, were used to estimate peak discharges, while the uniform distribution, Mononobe, Huff, and Yen and Chow methods were applied for the determination of temporal rainfall distribution. Two small watersheds, Baran (HP#6) and Banweol (WS#1), for which watershed hydrologic data were available since 1996, were selected as the study areas. A total of 41 rainfall events was chosen from the study watersheds to calculate peak runoffs and evaluate the performances of the selected hydrological models based on the statistics of RMSE, Nash efficiency criterion (NEC), and R² value. The Clark method performed the best overall among the selected models, with both NEC and R² values greater than 0.95. The Huff method resulted in the longest critical storm duration, which was much greater than the times of concentration. The increase in the recurrence interval decreased the critical storm duration while increasing the peak flow rates. The SCS model estimated the greatest design floods, 94.2 m³/s for HP#6 and 56.4 m³/s for WS#1, with a 25-year return period. The design floods for the study watersheds that were estimated by the selected hydrologic models ranged from 68.3 to 132.1% of those estimated by the Rational method. The greatest to the smallest peak flows resulted from the SCS, WFRP, Clark and Nakayasu methods in order. As an alternative to the Rational method, the WFRP method may be appropriate for rural watershed areas in Korea, where paddy fields commonly exist, whereas the SCS model may be more suitable for urban areas, where most land surfaces are covered with impervious material. It was concluded that the incorporation of a critical storm duration concept can contribute to the advance of design flood estimation method in Korea.     

长江上游流域暴雨洪水相似性判别指标研究

暴雨洪水发生演化的各个阶段之间存在一定的关联性和规律性。以长江上游流域为研究对象,将暴雨洪水指标分为降雨、洪水、时间、雨洪关系、水库、形状和初始指标7大类,共67个指标。通过整理暴雨历史洪水资料,摘录暴雨洪水过程和计算暴雨洪水特征值,结合洪量相似度、洪峰相似度、形状相似度和灰色关联度4种相似性评价方法,优选出降水量、降水历时、起涨流量和洪水涨率4个指标作为相似洪水判别指标。以113场三峡入库洪水为样本进行相似性检验,基于几场典型洪水特征值寻找的历史相似洪水之间的相似度较高,确定性系数都达到了0.9以上。结果表明,降水量、降水历时、起涨流量和洪水涨率4个指标作为相似洪水判别指标,对指导实时洪水预报具有较高的参考价值。研究成果在三峡水库以上长江上游流域进行了试验应用,在寻找历史相似洪水方面具有较好的效果。     

River regulation and riparian woodlands: Cottonwood conservation with an environmental flow regime along the Waterton River,Alberta

Following water withdrawal, riparian cottonwoods have declined downstream from some dams in western North America. Analyses of aerial photographs and field observations in the 1980s suggested that the black and narrowleaf cottonwoods (Populus trichocarpa and Populus angustifolia) along the Waterton River, Alberta, were declining due to drought stress following the 1964 damming and diversion. This raised concern for the riverine ecosystems and in 1991, “functional flows” commenced with 2 changes: (a) the minimum flow was increased from 0.9 to 2.3 m³/s (mean discharge 21.9 m³/s) and (b) flow ramping provided gradual stage recession after the spring peak. This provided an environmental flow regime that was delivered for 2 decades and this study investigated the consequent river flow patterns and riparian woodlands upstream and downstream from the Waterton Dam. Analyses of aerial photographs from 1951 to 2009 assessed 4 flow management intervals: (a) the free‐flowing predam condition, (b) the initial dammed interval to the mid‐1970s, (c) a drought interval in the 1980s, and (d) with the environmental flow regime after 1991. Analyses revealed woodland reduction from 1961 to 1985 due to losses through bank erosion with major floods and apparent decline due to low flows following a regional drought and water withdrawal for irrigation. With the subsequent environmental flow regime, there was apparent woodland recovery, despite drought in 2000 and 2001. This study demonstrated that the correspondence between river flow patterns and the extent of riparian woodlands and the benefit from the environmental flow regime that probably reduced drought stress and mortality.     

淮河上游紫罗山流域枯水频率及退水规律分析

应用枯季径流退水规律预报枯季径流总量和径流过程是枯季径流预报最常用、有效的方法。但目前,尚未有一种通用的分布可以很好地模拟所有枯水径流。以淮河上游紫罗山流域为研究对象,以1952～2010年各年最小7 d平均流量作为枯季径流统计特征序列,采用P-Ⅲ,LP-Ⅲ,GLO,GPA,LN3和GEV 6种分布,利用适线法、矩法等进行参数估计,推求经验频率对应的理论线型计算值。利用概率点据相关系数、四阶线性矩系数、确定性系数,均方根误差和平均绝对误差5个特征统计量,比较各分布线型拟合情况,确定该流域枯水频率最优拟合线型为P-Ⅲ分布。此外,利用退水曲线法推求各年份退水系数与多年综合退水系数。结果表明:流域年退水系数在0.007～0.200范围内波动,其变化与降水无关,随着最小7 d平均流量的变小而增大,流域多年综合退水系数为0.08。研究成果对合理开发利用水资源、保护河流生态系统平衡具有现实意义。     

全国小流域分布式单位线综合分析

基于全国小流域数据集,采用相关性分析和基于最小二乘法的多元回归非线性模型进行了小流域分布式单位线的综合分析,并以全国30个不同地形地貌类型区的中小流域为例开展了应用研究。研究表明:小流域不均匀系数、加权平均坡度反映了小流域汇流非均质分布特性,小流域属性与单位线特征值(洪峰流量、汇流时间和峰现时间)之间存在中度-强度相关关系;单位线洪峰流量、汇流时间和峰现时间最优公式型的均方根误差分别为0.14～0.75 m3/s、3.16～7.21 min和3.15～7.33 min,合格率分别为86%～100%、85%～100%和65%～100%,相关系数分别为0.93～0.99、0.89～0.99和0.83～0.98,构建的单位线特征值综合公式较好地反映了不同地形地貌类型区洪水集中度和汇集时间的差异性。研究可为缺资料地区中小流域暴雨洪水分析计算和山洪早期预报预警提供技术支撑。     

A customised approach to determining the geomorphic effectiveness of small flood events in a regulated river

The construction of dams significantly alters flow and sediment regimes with subsequent deleterious effects on the morphological and ecological character of rivers. Effective experimental floods can ameliorate the downstream geomorphic impacts of dams. The traditional view is that large floods are required to perform effective geomorphic work, and the geomorphic outcomes of small floods are often overlooked. Many river restoration frameworks do not consider small floods. Yet, there is evidence that the hydrological characteristics that ameliorate specific geomorphic impacts in a river are unique to each river, and a customised approach to setting the right mix of floods (including small experimental floods) is needed. In this study, we modify an existing flood effectiveness model developed for large floods, for determining the geomorphic effectiveness of small floods in a highly regulated Australian river. Two flood classes were added to the model (medium peak stream power and moderate total energy expenditure), and the flood power characteristics were rescaled to reflect the relative difference in the magnitude of the small floods and the magnitude of the geomorphic work performed. Using a step‐wise approach, this customised model determined the geomorphic effectiveness of small floods. The best flood for ameliorating the geomorphic impacts of flow regulation had medium to long duration (10 to 51 days), high peak unit stream power (77 to 123 Wm^?2) and moderate to large total energy expenditure (78,600 to 342,320 × 10³ J). This approach to determining flood effectiveness for small floods is applicable to other geomorphically impacted river channels downstream of dams and can be used to inform experimental flood releases for geomorphic outcomes.     

水文变异下淮河长吻鮠生境变化与适宜流量组合推荐

以淮河干流鱼类长吻鮠为保护目标,建立长吻鮠分时期生态需求与流量之间的概念性模型。对FLOWS法进行改进,加入水文变异前后长吻鮠生态环境对比分析,根据分析结果推荐一组适于长吻鮠生长繁殖的流量组合。结果表明,在环境流量成分的对比分析中,变异前的高脉冲流量历时长、发生时间合适,变异后发生洪水的频率增高,变异前的流量更适于长吻鮠的生长繁殖;在相关水力参数满足程度的对比分析中,在长吻鮠生长繁殖的各个时期,变异前的流量条件均优于变异后。选取变异前的平水年1970年的流量作为基础,推荐适宜流量组合,即产卵期的流量为545~1 212m~3/s,幼鱼索饵期应大于1 750 m~3/s,越冬期应大于等于74 m~3/s。该研究可为保护淮河珍稀物种,为淮河生态调度提供依据。     

Critical Flow for Water Management in a Shallow Tidal River Based on Estuarine Residence Time

To support the development of protective water resources management strategies, a 3D hydrodynamic model was applied to the Little Manatee River (LMR) to evaluate the effects of reducing river flow and drought on the Estuarine Residence Time (ERT). ERT is an important indicator for estuarine environmental quality. The Little Manatee River is a small tidal river estuary with a yearly mean gaged freshwater inflow of 4.8 m³/s. The hydrodynamic model was calibrated and verified by using two continuous data sets for a six month period. Model simulations were conducted for 17 river inflow scenarios. Among the flow scenarios, 13 scenarios were within a flow range from 0.26 m³/s to 10 m³/s total freshwater inflow. A regression equation (R ² = 0.98) fitted by a power-law function was derived from analysis of the hydrodynamic modeling results to correlate model predicted ERT to total river inflow, though ERT can be predicted from gaged freshwater inflow as well. The study indicates that the estuarine residence time reaches 53.3 days under an extreme drought condition of 0.26 m³/s total inflow. When river inflow falls below the critical flow (4 m³/s or less), further flow reductions can cause the substantial increases of ERT by a factor of 2 to 10 times. This suggests that the management of flow reductions is particularly critical when total river flows are 4 m³/s or less if adverse impacts to the water quality and ecological characteristics of the Little Manatee River are to be avoided.     

基于阻-导水通道的辽浑防洪保护区溃堤洪水淹没分析

为避免在影响水流运动的构筑物附近进行网格加密而导致计算效率降低的问题,本文采用阻水和导水通道数值模拟方法,以辽浑防洪保护区为研究对象,构建了基于阻-导水通道的水动力学模型,分析了超标准洪水下溃堤洪水的淹没过程及对研究区内社会经济的影响。结果显示：遇超标准洪水,陶家险工和偏养子堤段溃决后,保护区内将进入7.458亿m³和5.852亿m³洪量。受研究区内地势影响,溃决洪水由北向南宣泄,淹没面积达570 km²和268 km²,淹没过程中阻、导水通道较好地体现了构筑物对洪水演进的影响和作用。两种情景下,保护区内41 650 hm²和19 910 hm²农田将被淹没,21万和9万人口受洪水威胁,直接经济损失将达128亿元和52亿元。