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1.
山洪灾害是中国高频发、高死亡率的自然灾害之一。水雨情站网的合理布设及优化,有利于捕获区域暴雨、洪水情势变化的时空异质性,可显著提高中小流域山洪预警的精度,增强山洪灾害防御能力。本文以山洪灾害高发的福建省顺昌县为例,提出了面向山洪预警的水雨情站网布设方法。县内现状雨量和水位站网监测密度分别为37 km2/站和76 km2/站,主要分布在平原主干河流地区,山洪灾害重点防治区内站网布设不足,小流域暴雨山洪监测和预警能力较弱。针对上述问题,综合分析流域降雨时空特征、历史山洪灾害与山洪灾害预警预报需求,对研究区水雨情站网进行了合理性分析和布设研究,建议增设雨量站3座、水位站3座,其中一座水位站同时监测降雨过程,调整后县内雨量站和水位站的监测密度达到34 km2/站和68 km2/站。本文研究对山洪灾害高发区的水雨情站网布设具有参考和指导意义。  相似文献   

2.
Located in the headwater upstream of the Taihu Lake region, which is a densely populated and economically developed area in China, the West Tiaoxi River catchment is a frequently food-hit area due to its nature and climatic characteristics. During the last several decades, more than ten catastrophic floods happened in this area, causing huge economic losses. Since 1990, due to the increasing property vulnerability to flood hazard, the disasters were even more serious than before, and economic losses increased year by year. Thus, there have great importance to study flood behaviors, flood risks and their consequences. In this paper the hydrologic/hydraulic modelling is presented firstly. It is the method to study the relationship between rainfall and runoff and the flood propagation process. Secondly, the author gives the summary of the current study methods for flood risk assessment. The West Tiaoxi River catchment has a long history of the construction of polders and hydraulic engineering. Most farmlands have been protected against floods. So the combination method has been used to obtain the real risk area. The results have been obtained by using this method, which, the authors think, will be used in disaster preparedness, property insurance etc. Foundation item: Under the auspices of the National Natural Science Foundation of China (No. 49671028) and Deutsche Forschungsgemeinschaft (DFG). Biography: XU Peng-zhu (1965 —), male, a native of Funing County of Jiangsu Province, associate researcher. His research interests include hydrology and water resources, numerical modelling, and application of GIS to hydrology.  相似文献   

3.
Flashfloodsaretheimportanteventsofthehydrologicalregimeofriversinaridareas.IntheTarilncaver(Fig.1),northwesternChina,flashfledarebeingmonitored.TheobSerVeddataandinvestigationdemonstratethedifferenceintime,place,frequencyandintensityoftheiroccurrences.Therearethreet~offlagescommontotheThermcaverbasin.AlmOSteveryyea-rhighwateroccursinmonthesofJuly,AugUstandseptembercausedbyablationrunoff.However,themostdamagingflowSarefromoccasionalflashfindsbyinstenserainstormandglacierlakeoutburstflags(…  相似文献   

4.
基于洪峰模数的山洪灾害雨量预警指标研究   总被引：1，自引：0，他引：1  
山洪灾害预警是防御山洪的重要非工程措施,雨量预警指标是山洪灾害预警的关键。目前的雨量预警指标计算方法对水文气象资料条件以及模型建模率定都有很高的要求,并不适用于基层防汛人员。因此,本文基于全国山洪灾害调查评价成果数据,提出了一种运用洪峰模数计算雨量预警指标的简便、易用的方法。该方法以小流域洪水计算推理公式为基础,将公式中流量与流域面积的比值用洪峰模数表示,得到基于洪峰模数的临界雨量估算公式,并考虑流域土壤含水量等因素,分析临界雨量变化阈值,最终得到雨量预警指标。本文以云南省绥江县双河小流域为例,计算结果显示不同时段（1 h、3 h、6 h）净雨量和预警时段呈线性关系。降雨损失计算中洼地蓄水和植被截留在不同时段相同,土壤下渗在不同的时段不相同。在此基础上,计算不同土壤含水量条件下,不同时段的雨量预警指标。最后,对临界流量、降雨损失和预警指标进行了合理性分析,结果显示预警指标和调查评价结果及实测降雨都比较接近,计算的预警指标合理。本研究为基层山洪灾害预警提供了一种快速、便捷的预警指标计算方法,为预警指标计算提供技术支持。  相似文献   

5.
Introduction The Himalaya is considered to be the youngest mountains on the earth, and is tectonically very active, and hence inherently (geologically) vulnerable to hazards. Extreme rainfall events, landslides, debris flows, torrents and flash floods due…  相似文献   

6.
In recent years, flash flood disasters have occurred frequently in southwest China due to the increased frequency of extreme climate events. To solve this problem, great efforts have been made in studying the process of flash flood. However, little attention was paid on bearing body of hazard, the clusters of buildings. Thus the real disaster mechanism of flash flood remains unclear.Accordingly, based on the experiments of artificial flash floods in a conceptual solid model, this paper focuses on the flood-impacted inundation characteristics of the building clusters at different locations of the gully model, in order to obtain a better understanding of the disaster process and the interaction between the flash floods and building clusters. The results showed that, in a typical smallscale flash flood gully with hot and dry climate, 1)clusters of buildings on an alluvial fan could reduce about 35% of the flooding area by blocking the diffusion of the flood to the depression areas, and could also promote the deposition in lower reaches of the river channel by blocking the overbank flow from going back into the channel, making the width-depth ratio of the channel larger. 2) The flash flood rates of disaster and hazard on the alluvial fan are generally higher than that of the inner gully. For the inner gully,buildings located on the beaches along the lower river and the transitional areas of the straight channel and channel bends can easily be affected because of their lower elevations. For the alluvial fan, buildings nearby the meanders suffer the greatest impacts because of bank collapsing and flooding. 3) The safe vertical distance from a building to the river channel is 13 m for the buildings in the inner gully under extreme floods. Below this threshold, the smaller the vertical distance is, the greater the risk exposure is. For the buildings on the alluvial fan, especially for the buildings near the concave bank of the top rush point,the horizontal distance is more important, and the safe value is 80 m under extreme floods.  相似文献   

7.
针对现有暴雨型洪涝灾害预警方法时效性差的问题,提出了一种接入实时降雨数据的暴雨型洪涝灾害临灾预警方法。根据时序分析模型由历史降雨数据和实时降雨数据分析识别异常降雨,并将异常降雨、地形起伏、高程和河网因素作为影响因子,构建暴雨型洪涝灾害风险指数,以"日"为时间尺度进行短时暴雨型洪涝灾害风险分析。从异常降雨致灾角度出发,根据降雨的异常程度将暴雨型洪涝灾害风险等级划分为无风险、低风险、中风险、中高风险和高风险5个等级,进而实现临灾预警,为防灾减灾提供一定的参考信息。以广东省清远市2014年5月的洪涝灾害为例,接入5月21日至5月26日期间逐日降雨量数据,实现了临灾风险分析。实验结果表明,六日内清远市阳山县中下区域发生暴雨洪涝灾害的风险较大,与实际灾情相吻合,达到了较好的预警效果。  相似文献   

8.
在气候变化和城市化背景下,城市暴雨的局部特征愈发明显,而降雨监测和预报数据空间分辨率难以满足空间分布描述要求,造成城市洪涝模拟和预测结果存在不确定性。本文选择深圳市城区的3个流域,基于118场实测降雨数据,通过逐步增大网格尺寸以达到降低降雨空间分辨率的效果,同时以流域边界作为限制,保证流域内面平均雨量不变,然后将不同空间分辨率的降雨数据分别作为城市洪涝模型的输入条件,对流域出口断面的洪水过程进行模拟计算,每场降雨得到6种不同空间分辨率下的洪峰流量。结合降雨中心、流域几何中心等空间特征参数,分析降雨空间分辨率对流域洪峰的影响。研究结果表明,针对118场实测降雨,随着降雨数据空间分辨率逐渐降低,3个流域的出口断面的洪峰变化幅度逐渐增大;如果忽略了流域内部降雨数据的空间分布差异,洪峰变化幅度和方向与降雨中心和流域几何中心的空间关系具有相关性,降雨中心在流域几何中心上游方向的距离越大,洪峰降低的幅度越大。本文基于3个城市流域得到了相似的研究结论,研究方法可为城市流域洪涝模拟提供借鉴,研究结果可为河道洪水风险评价提供参考。  相似文献   

9.
China is highly susceptible to flood disasters and subjected to great damage every year. Furthermore, the flood frequency has exhibited an increasing trend in recent years. Most flood events, including flash floods and river flood, are induced by rainfall. This study investigates annual variations of rainfall occurrence over China during the period from 2000 to 2015 at the national and regional scale using daily rainfall data from the Tropical Rainfall Measuring Mission. The Mann-Kendall test is performed for trend detection, and statistical data of flood damage published by China’s government, including destroyed crop area, damaged buildings, direct economic loss, percentage of GDP (gross domestic product), and death toll are correlatively analysed with rainfall occurrences. The results show that storm rain events show the greatest variation among three rainfall types (moderate rain, heavy rain and storm rain). The variation coefficients of rainfall over Northeast China, North China, and Northwest China are the highest, whereas that for Southwest China is the smallest. Moderate rain, heavy rain over Central China, and moderate rain over Southwest China exhibits decreasing trends, whereas the remaining exhibit increasing trends. The correlation between the rainfall occurrences and these flood damage indices at the national scale shows that only direct economic loss has a strong positive correlation with rainfall occurrences, and the other indices have weaker correlations. The correlation is strong in three north regions, except for death toll in Northwest China. In contrast, the correlation between flood damage and rainfall is weak in East China, Central China, Southwest China, and South China. Overall, death toll is strongly correlated with the number of damaged buildings, implying that flood fatalities in China are likely associated with building collapse, and are dominated by specific extreme events. This study can provide a scientific reference for flood management in China.  相似文献   

10.
基于2004~2021年GRACE/GRACE-FO重力卫星数据反演黄河流域陆地水储量时空变化,并构建干旱指数模型和洪水因子模型,对黄河流域的极端气候现象进行分析研究。结果表明,2004~2021年黄河流域的陆地水储量以0.56 cm/a的速度减少,具有明显的季节周期性特征,在夏季和秋季呈盈余状态,春季和冬季呈亏损状态;干旱指数模型监测到期间黄河流域发生极度干旱事件22次、重度干旱事件37次,干旱事件范围涵盖整个黄河流域;洪水因子模型探测到黄河流域共发生洪水事件118次,多出现在夏季和秋季雨水较为丰沛的时候,期间黄河流域陆地水储量能力较弱,降雨量增大。利用GRACE/GRACE-FO重力卫星数据构建的干旱指数模型和洪水因子模型探测的气象结果与实际观测结果较为符合,能真实反映黄河流域发生的极端气候,可为极端气候研究提供有利工具。  相似文献   

11.
To improve flood control efficiency and increase urban resilience to flooding, the impacts of forest type change on flood control in the upper reach of the Tingjiang River (URTR) were evaluated by a modified model based on the Soil Conservation Service curve number (SCS-CN) method. Parameters of the model were selected and determined according to the comprehensive analysis of model evaluation indexes. The first simulation of forest reconstruction scenario, namely a coniferous forest covering 59.35 km2 is replaced by a broad-leaved forest showed no significant impact on the flood reduction in the URTR. The second simulation was added with 61.75 km2 bamboo forest replaced by broad-leaved forest, the reduction of flood peak discharge and flood volume could be improved significantly. Specifically, flood peak discharge of 10-year return period event was reduced to 7-year event, and the reduction rate of small flood was 21%-28%. Moreover, the flood volume was reduced by 9%-14% and 18%-35% for moderate floods and small floods, respectively. The results suggest that the bamboo forest reconstruction is an effective control solution for small to moderate flood in the URTR, the effect of forest conversion on flood volume is increasingly reduced as the rainfall amount increases to more extreme magnitude. Using a hydrological model with scenarios analysis is an effective simulation approach in investigating the relationship between forest type change and flood control. This method would provide reliable support for flood control and disaster mitigation in mountainous cities.  相似文献   

12.
全国山洪灾害调查评价成果及规律初探   总被引：2，自引：0，他引：2  
山洪灾害调查评价是1949年来水利行业最大的非工程措施项目,是规模最大的全国性防灾减灾基础信息普查工程,历时4年,涉及全国30个省305个市2138个防治县（区）,国土面积755万km2,人口近9亿。运用普查、详查、外业测量、分析计算等多种手段,掌握了中国山洪灾害防治区范围、人员分布、下垫面条件、社会经济、历史山洪灾害等基本情况,科学分析了山丘区小流域的暴雨洪水特性,评价了现状防洪能力,计算了预警指标,划定了危险区,为山洪灾害预警预报和应急救援决策提供了基础信息支撑。本文系统介绍了全国山洪灾害调查评价的核心要点,综述了调查评价成果,归纳了调查评价成果要素类型,揭示了全国山洪灾害防治区、人口、历史山洪灾害事件与预警能力的空间分布一致性,即山洪灾害各要素集中分布于青藏高原-四川盆地过渡带、川滇交界地区、黄土高原区、东部沿海地区及华北等地区,最后初步探讨了该成果的应用前景。全国山洪灾害调查评价成果将为中国山洪灾害监测预警预报体系建设及防灾减灾能力提升提供丰富的基础数据支撑。  相似文献   

13.
As a major sediment area in the upper Yangtze River, Jialing River basin experienced substantial land-use changes, many water conservancy projects were constructed from the 1980 s onward to promote water and soil conservation. The water and sediment yield at the watershed outlet was strongly affected by these water conservation works, including ponds and reservoirs, which should be considered in the modelling. In this study, based on the observed data of the Weicheng River catchment, the relationships between precipitation, runoff, vegetation, topography and sediment yield were analyzed, a distributed runoff and sediment yield model(WSTD-SED) was developed, and the hydrological processes of different land-use scenarios were simulated by using the model. The main results are summarized as follows: 1) there is an alternating characteristic in river channels and reservoirs in the Jialing River hilly area, with scour occurring in wet years and deposit occurring in dry years. 2) Most of the sediment deposited in river channels and reservoirs is carried off by the largest flood in the year. 3) The model yielded plausible results for runoff and sediment yield dynamics without the need of calibration, and the WSTD-SED model could be usedto obtain qualitative estimates on the effects of land use change scenarios. 4) The modelling results suggest that a 10% increase in cropland(dry land) reforestation results in a 0.7% decrease in runoff and 1.5% decrease in sediment yield.  相似文献   

14.
The precision modeling of dam break floods can lead to formulation of proper emergency action plan to minimize flood impacts within the economic lifetime of the assets.Application of GIS techniques in integration with hydrological modeling for mapping of the flood inundated areas can play a momentous role in further minimizing the risk and likely damages.In the present study,dam break analysis using DAMBRK model was performed under various likely scenarios.Probable Maximum Flood (PMF)calculated for a return period of 1000 years using deterministic approach was adopted for dam break analysis of the proposed dam under various combinations of breach dimensions.The available downstream river cross-sections data sets were used as input in the model to generate the downstream flood profile.Dam break flow depths generated by the DAMBRK model under various combinations of structural failure are subsequently plotted on Digital Elevation Model(DEM)of the downstream of dam site to map the likely affected area.The simulation results reveals that in one particular case the flood without dam may be more intense if a rainfall of significant intensity takes place.  相似文献   

15.
气候变暖背景下高海拔山区融雪（冰）以及强降水引发的洪水愈加难以预测,通过山区雨雪分离可判定引发洪水的温度条件,从而为山洪准确预报提供简单而科学的参考依据。本研究以昆仑山提孜那甫河流域为例,基于流域内不同海拔气象站2012-2016年的降水以及温度数据,结合MOD10A2积雪数据,采用温度积分法和概率统计方法,利用研究期内的平均温度,确定出不同降水形态对应的温度条件,以达到雨雪分离的目的。研究结果表明,莫木克站最大温和积温分别达到20.91 ℃和51.82 ℃时,降水可判定为降雨,最大温和积温分别低于18.13 ℃,43.69 ℃时,降水可判定为降雪;库地站最大温和积温分别达到14.51 ℃,33.17 ℃时,降水可判定为降雨,最大温和积温分别低于13.57 ℃,31.68 ℃时,降水可判定为降雪;西合休站最大温和积温分别达到9.43 ℃,19.53 ℃时,降水可判定为降雨,最大温和积温分别低于8.22 ℃,19.4 ℃时,降水可判定为降雪。利用流域内气象站点附近乡镇的气象统计数据对温度条件及分离结果进行验证,在海拔2000 m以下、2000~3000 m以及3000 m以上不同海拔地区的准确率分别为92.86%、79.49%以及88.3%。本研究可为判别洪水类型和洪水预报提供科学参考。  相似文献   

16.
Intense human activities have greatly changed the flood generation conditions in most areas of the world, and have destroyed the consistency in the annual flood peak and volume series. For design flood estimation, coaxial correlation diagram and conceptual hydrological model are two frequently used tools to adjust and reconstruct the flood series under human disturbance. This study took a typical mountain catchment of the Haihe River Basin as an example to investigate the effects of human activities on flood regime and to compare and assess the two adjustment methods. The main purpose is to construct a conceptual hydrological model which can incorporate the effects of human activities. The results show that the coaxial correlation diagram is simple and widely-used, but can only adjust the time series of total flood volumes. Therefore, it is only applicable under certain conditions (e.g. There is a strong link between the flood peaks and volumes and the link is not significantly affected by human activities). The conceptual model is a powerful tool to adjust the time series of both flood peak flows and flood volumes over different durations provided that it is closely related to the catchment hydrological characteristics, specifically accounting for the effects of human activities, and incorporating expert knowledge when estimating or calibrating parameters. It is suggested that the two methods should be used together to cross check each other.  相似文献   

17.
小流域山洪灾害危险性分析之降雨指标选取的初步研究   总被引：1，自引：0，他引：1  
降雨是诱发山洪灾害的直接动力和激发条件,是山洪灾害危险性分析中不可或缺的重要指标。对于不同的研究区,不同频次和历时的降雨对山洪灾害的影响不同,危险性分析所选取的降雨指标也可能不同。本文基于1:5万小流域数据、历史山洪灾害空间分布数据和暴雨图集资料,以江西省婺源县小流域为例,采用相关分析法对初步选取的24个降雨指标进行相关性分析,筛选出相关性不强的降雨指标;利用GIS技术和基于局部Getis-Ord Gi*算法的优化热点分析工具对历史山洪灾害点进行空间聚类分析,获得研究区每个小流域山洪灾害危险度的估值,该值能够较好地反映小流域山洪灾害危险性的空间分布;通过地理探测器模型中的因子探测器和交互探测器对已筛选出的降雨指标和小流域山洪灾害危险度进行综合探测分析,从而获取对该研究区小流域山洪灾害危险性影响较大的降雨指标,即100年一遇最大6 h降雨和100年一遇最大24 h降雨。本文研究对小流域山洪灾害危险性分析降雨指标的定量选取具有参考和指导意义。  相似文献   

18.
Climate change has altered locally single-type disasters to large-scale compound disasters because of increasing intensity and frequency of extreme rainfall events. The compound disasters can combine small-scale floods, debris flows, shallow landslides, deep-seated landslides, and landslide lakes into a large-scale single disaster event. Although simulation models and evaluation tools are available for single-type disasters, no single model is well developed for compound disasters due to the difficulty of handling the interrelationship between two successive single-type disasters. This study proposes a structure for linking available single-type simulation models to evaluate compound disasters and provides a useful tool of decision making for warning and planning of disaster reduction.  相似文献   

19.
极端降水极易引发山洪和城市内涝等水灾害,给生态环境安全、社会经济发展、人民生命财产安全等带来极大损失,认识其（尤其是短历时）空间分布差异对洪涝灾害防治等具有重要意义。本文利用60 min、6 h和24 h共3种历时的年最大降雨量的统计特征参数,生成服从皮尔逊-Ⅲ型分布的长序列样本,并选用信息熵指标研究其随机性及空间分布差异。结果显示：各历时年最大降雨量的随机性均呈现由东南向西北逐渐减小的空间格局,但不同历时降水随机性的空间分布存在差异,主要体现在青藏高原东部、海河流域和淮河流域3个区域。此外,所求年最大降雨量信息熵值主要考虑了其取值的相对离散情况,故该信息熵值与整个序列绝对离散程度（即标准差）的关系不明显,而主要由序列均值处峰值高低的峰度系数决定,二者呈现明显的负相关关系;且由于峰度系数和变差系数的良好相关性也导致了变差系数与信息熵值之间呈现出良好关系。季风、台风、局地天气系统和人类活动等因素综合影响,决定了不同历时极端降水的空间分布格局及其差异。信息熵指标可以很好地反映中国各历时年最大降雨量随机性的空间分布格局,因而结果可为洪涝灾害防治、农业规划布局、生态环境规划保护等提供科学依据。  相似文献   

20.
One of the most vulnerable parts to natural hazards in Serbia is Kolubara river basin. In the past, during the period from 1929 to 2013, 121 torrential flood events in the Kolubara river basin were recorded which show that this territory is extremely vulnerable to the torrential floods. The extreme event which occurred in May 2014 causing the catastrophic material damages and casualties was the latest and historical flood. The analysis of natural conditions in the Kolubara basin uniformly showed that this area is predisposed to a greater number of torrential floods due to its geomorphological, hydrological and land use properties. Torrential floods are closely related to the intensity and spatial distribution of erosive processes in the upper part of the Kolubara basin. The estimation of soil erosion potential is generally achieved by Erosion Potential Model (EPM). For the purposes of determining the degree of torrential properties in various water streams in the Kolubara basin, the calculation of susceptibility to torrential floods was assessed by Flash Flood Potential Index (FFPI). More than half of the basin area (57.2%) is located within the category of very weak and weak erosion (Zsr = 0.35), but the category of medium erosion is geospatially very common. Such a distribution of medium erosion category provides conditions for generating, i.e. production of sediment which would boost torrential properties of water streams. After the classification of the obtained FFPI values it was determined that 25% of the Kolubara basin is very susceptible to torrents and this data should be seriously taken into consideration. Based on the analyses, the best and most successful manner of defence is prevention which consists of the integrated river basin management system (integrated torrent control system) so that technical works in hydrographic networks of torrents and biological and biotechnical works on the slope of the basin would be the best solution. Permanent control of erosive and torrential processes in the river basin will be not only important for flood control but it can also protect the existing and future water reservoirs and retentions from siltation with erosion sediment which is of great significance to the water management, agriculture, energy sector, and the entire society.  相似文献   

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