乌鲁木齐河同频率设计洪水探讨

依据乌鲁木齐河实测洪水资料分析可知,当发生相同频率的洪水时,其时段洪量出现的几率并不与洪峰流量频率同步,将洪峰流量与时段洪量排序后,发现时段洪量的序号同洪峰序号有较大差异。但时段洪量频率分布应与洪峰流量频率分布有一定的相关性,在规划、设计、防洪调度等工作中,注重同频率设计洪水相关性和差异,并在宏观上开展对洪水的研究。     

EXPERIMENTS OF INFLUENCE OF DISCHARGE PROCESS ON CHANNEL PATTERN

Based on experimental data and theory, by means of simplified discharge durations in a small flume,the influence of discharge process on channel morphology and channel pattern was analyzed in this paper. It was concluded that on the same original channel, different discharge and channel conditions would end with different river morphology, including thalwegs and radius of bends. Different discharge process resulted in two kinds of change:tiny change in the process of “big-small-big” and distinct change in the process of “small-big-small”. Flood discharge duration was verified to be the main cause in the discharge process. Proper discharge process will change the morphologies of river, even can led to channel pattern transformation. The influences based on the relationship between the flow and the channel itself, including slope and riverbed constitution. Although not be a main cause, original channel morphology may influence its final channel pattern. Neglecting the influence of channel itself will hamper the understanding of channel patterns.     

基于分布式水文模拟的三峡区间洪水预报(Ⅱ)——雷达测雨应用

降雨时空分布信息缺失是影响洪水预报精度的一个重要因素,尤其是雨量站点稀疏的山区,站点观测的降雨信息难以充分地表征山区降雨的空间差异.本文针对长江三峡区间,利用雨量站点观测值来校准雷达测雨数据,并作为分布式水文模型的降雨输入,借助水文模拟结果综合评价雷达测雨数据的适用性.两个示例小流域的研究结果表明:相对于雨量站而言,雷达估测的降雨信息更能体现降雨的空间变化,它与分布式水文模型相结合,是提高洪水预报精度的有效途径.     

入海水系整治水情数值模拟方法

入海水系河道纵横交错，其水流同时受上游河道来水、下游出口潮汐顶托、水工建筑物调控等的综合影响，水文情势十分复杂。采用水文预报与数值模拟结合的方法，对上游各边界河道采用由瞬时单位线法推得的设计洪水过程作为入流条件，对入海边界根据潮位过程及水工建筑物调节规程确定出流边界条件，进行了来水与潮位不同遭遇多种工况下的水文水流预测模拟，为水系整治提供水情依据。     

牟汶河下游汛期分期及洪水分级的确定

为实现对牟汶河下游蓄水建筑物进行汛期动态控制,依据流域范家镇站、北望站和大汶口站3个雨量站1980~2011年日降雨资料,采用模糊分析方法,对牟汶河下游汛期进行了分期;以北望站同时期的历年最大洪峰流量资料,利用重现期法确定了洪水分级流量。     

太湖流域应对特大洪水防洪工程效益模拟

防洪效益评估对防洪工程投资决策与减灾对策制定具有重要意义。建立集成了与太湖流域防洪效益评估相关的系列模型和方法,包括含降雨产流与平原净雨计算的水文分析方法、由河网水动力学模型和平原区域洪水分析模型组成的大尺度水力学模型、综合流域社会经济和淹没因素的洪灾损失评估模型。模拟了太湖流域遇特大洪水的灾害损失,开展了不同防洪工程应对流域性特大洪水减灾效益的预测分析。结果表明：1999年型200年一遇降雨将会给太湖流域造成高达568.29亿元的直接经济损失,外排动力增强30%至100%的防洪效益介于26.69亿元到45.70亿元之间,新建圩区、太浦河拓宽的防洪效益依次减小,而圩区泵排能力增加30%的防洪效益仅为0.65亿元。基于研究成果提出了增设外排泵站、加强圩区科学调度、通过保险分担风险等应对特大洪水的对策措施建议,为太湖流域特大洪水的防治提供支撑和参考。     

Sentinel-1 SAR在洪水范围提取与极化分析中的应用研究

在洪水灾情监测中,快速准确的获取淹没区域和洪灾面积,对防汛救灾和灾后重建工作具有重要价值.本文以2017年美国圣路易斯洪水为例,基于Sentinel-1 SAR数据,利用变化检测和阈值相结合的方法实现大范围洪水淹没提取,将VV/VH极化数据分别与从同期Sentinel-2光学影像中获取的洪水淹没范围进行比较,评定极化方...     

Global snowmelt flood disasters and their impact from 1900 to 2020北大核心CSCD

Under the background of climate warming, the occurrence time, frequency, intensity, and impact of snowmelt flood disasters have changed significantly. Thus, establishing a global snowmelt flood disaster database is particularly important for disaster risk management. With the help of a web crawler, and based on multiple data sources such as natural disaster databases, documents, books, government agency websites, and news media, this study collected relevant information of snowmelt floods and mixed floods and established standards for identifying snowmelt flood events and their disaster impacts based on data from the different sources. Following the screening, sorting, fusion, and integration of snowmelt flood events, a global snowmelt flood disaster dataset containing 579 pieces of data with strong pertinence and reliability was constructed. The temporal and spatial distribution characteristics of global snowmelt flood disasters from 1900 to 2020 were preliminarily analyzed. The results showed that the snowmelt floods were mainly distributed between 30° N and 60° N, with more mixed floods south of 50° N and more snowmelt floods north of 50° N. Spring was the period of highest incidence of snowmelt flood disasters, followed by winter, summer, and autumn, respectively. The snowmelt floods that occurred in spring, autumn, and winter were mainly at 40°~50° N, and the snowmelt floods that occurred in summer were mainly at 30°~40° N. Compared with the snowmelt floods, the mixed floods were more frequent and more destructive, and their frequency increased with climate warming. The results provide a scientific basis for risk prevention and loss assessment of global snowmelt flood disasters. © 2022 Science Press (China).