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洪水淹没范围是洪水影响的直接反映,也是洪水影响评估的基础.利用GIS工具将河段洪水水位转换为三维栅格水位,与区域的DEM进行淹没分析,结合河岸堤防高程修正,便捷地得到洪水影响范围,可以作为超标准洪水预案、洪水淹没影响评估等的决策参考. 相似文献
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溃坝洪水的演进过程及其对下游城市的淹没影响是大坝安全的重要研究内容之一。以我国南方某山区河流为例,采用数值计算方法,针对该流域上并(串)联的4座水库在多种溃坝模式下,对下游城市的淹没过程进行了计算和讨论分析。研究结果表明溃坝洪水在下游城市的淹没速度和最大淹没面积主要与最大溃坝流量相关,即与溃坝水头和溃口大小相关;最大淹没面积的达到时间主要与城市与水库间的行洪距离有关。梯级水库发生连溃时,溃坝洪水对下游城市的淹没速度和淹没面积都较单个水库溃坝更加严重,不过连溃洪水在下游城市呈现淹没快、退水也快的特征。城市洪水的淹没历时主要与溃坝水库的容积相关,与最大溃坝流量的关系不大。 相似文献
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根据山洪灾害防治项目要求,重点开展了城镇区域的洪水影响及淹没分析研究,选择湖北省保康县作为典型山区城镇开展实例研究。通过对保康县的实地查勘,资料收集,设计洪水计算方案,建立水动力学模型、洪水演进分析模型、洪水淹没分析模型;并以100 a一遇设计洪水为例,对城区受淹地区及其淹没水深、淹没面积等进行了分析。结果表明,该方法具备良好的理论基础,有效实现一维、二维模型嵌套,计算速度快,能够取得精准、合理可靠的洪水影响分析成果和洪水淹没成果,可为防汛决策部门提供参考。 相似文献
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本文针对山区中小型河流洪水资料相对较少的情况,以地形数据DEM为基础,分析区域各典型频率洪水,计算淹没范围和淹没水深,并计算不同频率洪水淹没损失,以流域为单位绘制洪水淹没图,以试点县岫岩地区内河流为例,绘制各典型频率洪水淹没图,为洪灾损失评估和洪灾风险评价提供数据基础,为规划编制、监测预警提供信息支撑. 相似文献
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文章采用Mike21软件,选择从破台子大桥至北关桥下游的橡胶坝之间为计算区域,对河道10年一遇洪水进行二维计算,然后根据结果,分析确定生态湿地各分区内的淹没范围和淹没水深。 相似文献
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以永定河泛区水情分中心系统为实例,系统通过集成设计来统一考虑硬件、软件配置,减少由于系统的划分造成的硬件、软件重复建设,达到提高系统建设资金使用效益的目的。 相似文献
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对城市排涝工程设计中采用的雨洪同期设计暴雨计算方法进行探讨,提出年最大样本法的计算思路,并建议试行该法. 相似文献
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分析总结了黄泛平原区"水城"的景观形态和形成机制,指出这类城市是经历洪涝灾害的适应性景观.针对近年来"水城"景观被破坏和一系列错误的建设方式,提出"水城"建设不应仅限于提升城市形象,更需致力解决城市面临的洪涝灾害、水资源短缺、水污染、水生态恶化等综合性问题.提出从水伦理、宏观生态基础设施规划和场地生态设计三个层面进行"水城"保护和建设,系统建设以水为核心的城市生态环境.最后对菏泽市的水系统进行了规划探讨,在尊重和保护原有的菏泽水城景观基础上.根据城市发展的需要,设计建立更系统完善的、以水系为核心的生态基础设施,将水系与生物栖息地、城市游憩绿地和文化遗产等多个系统整合在一起,以便发挥其综合的生态服务功能.这一系统的建立将可以有效地防止洪涝灾害,并资源化利用雨洪,避免单一水利工程带来的弊端. 相似文献
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DEM是表征地形状况的重要指标,在山洪淹没模拟中起着重要作用。以2016年7月19日发生在河北省石家庄市井陉县西部山区的特大暴雨山洪事件为研究对象,利用HEC-HMS水文模型和FLO-2D水动力模型,设置5种DEM分辨率方案(30、20、15、10、5 m),从淹没范围和淹没水深两方面分析了DEM分辨率对山洪淹没模拟的影响,并从模型运行时间角度对其运行效率进行了评估。研究表明:DEM分辨率越高,则淹没范围越小,平均淹没水深越大,即模型模拟精度越高,山洪事件的淹没范围及水深越接近于实际调查情况(DEM分辨率为30和5 m时,淹没范围及淹没深度的模拟精度分别为0.56和0.41、0.76和0.79);随着DEM分辨率的提高,尤其从10 m提高至5 m时,模拟结果差异减少,模拟精度的增幅也减小,淹没范围和水深的精度增幅分别为2.70%和3.94%;DEM分辨率越高,则模型运行时间越长,模型运行效率越低,5 m DEM方案下的运行时间为30 m DEM方案的700倍。综合考虑模拟精度及模拟时间,10 m分辨率的DEM对山洪淹没模拟、风险评估及预警预报等更为适用。 相似文献
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While many controlled irrigation and drainage techniques have been adopted in China, the environmental effects of these techniques require further investigation. This study was conducted to examine the changes of nitrogen and phosphorus of a flooded paddy water system after fertilizer application and at each growth stage so as to obtain the optimal drainage time at each growth stage. Four treatments with different water level management methods at each growth stage were conducted under the condition of ten-day continuous flooding. Results show that the ammonia nitrogen (NH+4-N ) concentration reached the peak value once the fertilizer was applied, and then decreased to a relatively low level seven to ten days later, and that the nitrate nitrogen (NO-3-N) concentration gradually rose to its peak value, which appeared later in subsurface water than in surface water. Continuous flooding could effectively reduce the concentrations of NH+4-N, NO-3-N , and total phosphorus (TP) in surface water. However, the paddy water disturbance, in the process of soil surface adsorption and nitrification, caused NH+4-N to be released and increased the concentrations of NH+4-N and NO-3-N in surface water. A multi-objective controlled drainage model based on environmental factors was established in order to obtain the optimal drainage time at each growth stage and better guide the drainage practices of farmers. The optimal times for surface drainage are the fourth, sixth, fifth, and sixth days after flooding at the tillering, jointing-booting, heading-flowering, and milking stages, respectively. 相似文献
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Summer floods occur frequently in many regions of China,affecting economic development and social stability.Remote sensing is a new technique in disaster monitoring.In this study,the Sihu Basin in Hubei Province of China and the Huaibei Plain in Anhui Province of China were selected as the study areas.Thresholds of backscattering coefficients in the decision tree method were calculated with the histogram analysis method,and flood disaster monitoring in the two study areas was conducted with the threshold method using Sentinel-1 satellite images.Through satellite-based flood disaster monitoring,the flooded maps and the areas of expanded water bodies and flooded crops were derived.The satellite-based monitoring maps were derived by comparing the expanded area of images during a flood disaster with that before the disaster.The difference in spatiotemporal distribution of flood disasters in these two regions was analyzed.The results showed that flood disasters in the Sihu Basin occurred frequently in June and July,and flood disasters in the Huaibei Plain mostly occurred in August,with a high interannual variability.Flood disasters in the Sihu Basin were usually widespread,and the affected area was between Changhu and Honghu lakes.The Huaibei Plain was affected by scattered disasters.The annual mean percentages of flooded crop area were 14.91% and 3.74% in the Sihu Basin and Huaibei Plain,respectively.The accuracies of the extracted flooded area in the Sihu Basin in 2016 and 2017 were 96.20% and 95.19%,respectively. 相似文献
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基于实测断面资料建立了研究区的一维水动力模型,基于高精度DEM以及1∶10000地形图建立了研究区的二维水动力模型,并用MIKE FLOOD将一维模型和二维模型进行耦合,构建了洪泽湖周边滞洪区一、二维耦合的洪水演进数学模型。利用2003年历史洪水资料对模型参数进行了率定,并以2007年历史洪水资料进行了验证。以洪泽湖百年一遇设计洪水为模型上边界,二河闸、三河闸以及高良涧闸的现行调度方案的水位-流量关系为模型下边界,对洪泽湖百年一遇设计洪水方案进行模拟计算,当蒋坝水位达到14.33m时,洪泽湖周边滞洪区开始滞洪,得到开始滞洪后不同时段研究区内各类洪水风险要素的动态分布情况以及最大淹没水深、淹没历时,验证了模型的合理性,可用于蓄滞洪区洪水演算分析。 相似文献