论抵御''98洪水与洪水风险管理

1998年长江流域发生了自1954年以来又一次全流域性大洪水，嫩江和松花江流域也发生了超历史记录的特大洪水．从抵御’98洪水中得出，必须改变单纯的抵御洪水的观念，要对洪水实行全过程风险管理．进行洪水风险管理，最主要的是制定针对洪水灾害的政策．并进一步分析了蓄滞洪区的管理，应加强以下几方面的建设：（1）控制和减少人口；（2）加强安全设施建设；（3）绘制洪水风险留，建立和完善避难的预报和预警系统；（4）建设分蓄洪控制工程；（5）严格土地利用规划及管理，调整产业结构；（6）实行洪水保险制度．     

FLOOD INUNDATION MAPPING FOR INTEGRATED FLOODPLAIN MANAGEMENT: UPPER MISSISSIPPI RIVER SYSTEM

Natural hydrogeomorphic characteristics and hydrologic alterations are important ecological drivers, and hydrology is also a common ecological, flood control and navigation system indicator. Hydrologic characteristics change dramatically from one end of the Upper Mississippi River System to the other, and hydraulic characteristics also differ spatially across the river channels and floodplain in response to dams, levees and diversions. Low flow surface water spatial change in response to navigation and flood control has been well known for many years, but little information was available on the spatial distribution of frequent floods. The flow frequency data presented here were developed to better estimate contemporary floods after historic flooding in 1993. Flood stage estimates are enhanced in GIS to help quantify and map potential floodplain inundation for more than 1000 river miles on the Upper Mississippi and Illinois Rivers. Potential flood inundation is mapped for the 50% to 0.2% annual exceedance probability flood stage (i.e. 2‐ to 500‐year expected recurrence interval flood) and also for alternative floodplain management scenarios within the existing flood protection infrastructure. Our analysis documents: (i) impoundment effects, (ii) a hydrologic gradient within the navigation pools that creates repeating patterns of riverine, backwater and impounded aquatic habitat conditions, (iii) potential floodplain inundation patterns for over 2 million acres and (iv) several integrated floodplain management scenarios. Extreme flood events are more common in recent decades, and they are expected to continue to occur at greater frequency in response to climate change. Floodplain managers can use the results presented here to help optimize land management and flood damage reduction on the Upper Mississippi River System. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.     

Uncertainty Estimation in Flood Inundation Mapping: An Application of Non‐parametric Bootstrapping

Disaster prevention planning is affected in a significant way by a lack of in‐depth understanding of the numerous uncertainties involved with flood delineation and related estimations. Currently, flood inundation extent is represented as a deterministic map without in‐depth consideration of the inherent uncertainties associated with variables such as precipitation, streamflow, topographic representation, modelling parameters and techniques, and geospatial operations. The motivation of this study is to estimate uncertainties in flood inundation mapping based on a non‐parametric bootstrapping method. The uncertainty is addressed through the application of non‐parametric bootstrap sampling to the hydrodynamic modelling software, HEC‐RAS, integrated with Geographic Information System (GIS). This approach was used to simulate different water levels and flow rates corresponding to different return periods from the available database. The study area was the Langat River Basin in Malaysia. The results revealed that the inundated land and infrastructure are subject to a flooding hazard of high‐frequency events and that the flood damage potential is increasing significantly for residential areas and valuable land‐use classes with higher return periods. The proposed methodology, as well as the study outcomes, of this paper could be beneficial to policymakers, water resources managers, insurance companies and other flood‐related stakeholders. Copyright © 2017 John Wiley & Sons, Ltd.     

不同降雨集中度下流域干支流洪水全过程模拟

为研究流域洪水形成过程及淹没风险规律,采用二维全水动力模型GAST模拟灞河部分流域的降雨成洪情况,分析不同降雨集中度下的洪水形成过程及淹没风险区变化规律。结果表明,降雨集中度影响流域洪水的洪峰流量与峰现时间,也影响淹没风险区面积及峰值出现时间。雨量大且集中的降雨容易在短时间内形成大洪峰洪水,也较快达到淹没风险区面积峰值;流域干支流在出山口断面峰现时间顺序为清峪沟、流峪河、灞河上游、蓝桥河,汇流起始点与流域出口断面峰现时间最大相差80 min;淹没风险区域主要分布于流域出山口外的灞河干流沿河两岸,淹没面积达到峰值最早为低风险区,最晚为极高风险区,峰现时间均在4 h之前。流域干支流洪水过程及淹没风险变化过程分析结果可为灞河流域不同降雨条件下的防洪响应及部署提供参考。     

黄河下游滩区淹没损失估算研究

通过典型调查取得滩区社会经济指标和洪水淹没损失指标,计算滩区耕地亩均产值和洪水淹没损失率,并根据预估的不同量级洪水淹没面积,估算不同量级洪水淹没损失,为制定黄河下游滩区补偿标准和执行补偿政策的决策提供依据。     

Integrated Risk Management of Flood Disasters in Metropolitan Areas of China

A review of flood disasters in China during the past five decades has shown a steady increase in the disaster toll due to rapid urbanization, especially through landscape urbanization in metropolitan areas. This paper illustrates the relationship and the interactions between urbanization in the metropolis and the process of flood disaster changes. Furthermore, a solution is proposed to alleviate fluctuations in flood disasters through the adjustment of the land use structure and pattern in metropolitan areas. Based on the solution, the authors conclude that the proportion of ‘ecological land’ in metropolitan areas should not be lower than 40%. The proportion of water and wetlands in ecological land should not be lower than their area in the years of average precipitation and water level. This means that in the Pearl River Metropolitan Area and the Yangtze River Delta Metropolitan Area, the proportion of water and wetlands in ecological land should be more than 25%. Moreover, the authors propose constituting a regional management mode which combines government, society, and insurance companies for controlling flood risk in metropolitan areas.     

优化防洪调度合理确定大藤峡水利枢纽防洪库容规模

大藤峡水利枢纽是西江流域的防洪控制性枢纽工程,但由于正常淹没实物指标大且存在防洪超蓄运用问题,导致工程迟迟不能立项.为促使大藤峡工程顺利实施,珠江委在新一轮《珠江流域防洪规划》中,调整思路,对大藤峡的防洪调度规则、防洪库容规模、起调水位及调洪任务进行优化,在确保流域防洪安全的前提下,将兴利库容与防洪库容完全结合,大大减少了水库正常淹没的实物指标,避免了水库调洪超蓄运用.     

十三围防洪保护区洪水风险分析

十三围防洪保护区位于珠江河网区域的西江和北江交汇后的西江右岸,西江洪水峰高量大,洪水威胁严重,进行洪水风险分析十分必要。考虑到珠江河网区域水流运动复杂,基于一维水动力学模型构建了珠江河网一维模型,并根据历史洪水资料验证了模型的可靠性。为了反映保护区内的河道、堤防、道路等对洪水传播的影响,采用精细化的非结构网格构建了十三围保护区二维水动力学模型进行洪水演进模拟。通过一、二维耦合模型,分别对江根段、西头窦段溃口进行了西江50,100,200 a一遇设计洪水下的洪水淹没方案计算,并对计算成果进行了合理性分析,包括水量平衡分析、局部流场分析、溃口流量水位过程分析等。结合社会经济数据进行了受淹面积、受影响人口、淹没损失等方面的洪水影响分析,可为防汛抢险、避洪转移等提供重要信息参考。     

梅溪流域城镇化进程对山前平原区洪涝过程的影响

为探究城镇化进程引起土地利用类型变化对山前平原区洪涝过程的影响,以梅溪流域下游平原区的洪濑镇为例,分析了2002—2018年梅溪流域上游山区和下游平原区的土地利用类型变化,并基于多情景数值模拟,研究了流域尺度内土地利用类型变化对山前平原区洪涝过程和地表淹没状况的影响。结果表明：随着梅溪流域耕地和林地面积减少、城镇建设用地增加,上游山区的径流系数和峰值流量均增大,下游山前平原区的淹没状况更加严重;上游山区的城镇建设用地增加使山区骤发洪水峰值流量增大、峰现时间提前,主要影响地表平均最大淹没水深和平均峰现时间;下游平原区的城镇建设用地增加使内涝发生的时间提前,主要影响地表平均淹没历时。     

内涝和外洪遭遇情景下洪水风险要素解耦模拟

特定洪源作用下的洪水风险要素是编制洪水风险图、开展洪水风险管理的基础。在内涝、外洪等多洪源遭遇情景下,因多洪源耦合作用于洪水风险要素,解耦特定洪源作用下的洪水风险要素是洪水风险分析的难点。基于示踪剂法原理,提出内涝和外洪遭遇情景下洪水风险要素解耦方法。该方法是将特定洪源表示为含有标志示踪剂的源汇项,利用溶质运移模型模拟得到标志示踪剂浓度时空变化过程,通过标志示踪剂分布范围解析特定洪源前锋到达时间,将标志示踪剂浓度比例与淹没水深数量积视为特定洪源作用下淹没水深。解耦方法经过理论公式推导,并通过案例实证进行了验证。以淮河干流 1991 年洪水蒙洼蓄洪区典型进洪过程为例,对蓄洪区启用后区内淹没水深、前锋到达时间等洪水风险要素进行解耦,并绘制了进洪洪水前锋到达时间,以及内涝、进洪洪水作用下淹没水深空间分布图。区内蓄洪量解耦为进洪量和暴雨内涝积水量,第 1 次进洪结束时,进洪量占蓄洪量的 85.47%;第 2 次进洪结束时,第 1 次进洪洪水、第 2 次进洪洪水及内涝水量分别占蓄洪量的 26.80%,64.15%,9.05%。在内涝和外洪遭遇情景下,运用该方法能够快速准确提取进洪洪水的前锋到达时间,且能解耦受内涝、进洪洪水等洪源作用下的淹没水深。     

鄱阳湖淹没范围、水深和库容的遥感研究

鄱阳湖湿地是国际重要湿地,也是长江的主要蓄洪区,研究鄱阳湖淹没范围、淹没水深和库容对长江流域水文和湿地保护都有重要意义。通过对13个时相的Landsat卫星遥感影像进行非监督分类提取湖泊水体淹没范围,叠加鄱阳湖区地形图,获取水体边界的水位,通过空间内插计算鄱阳湖水位空间分布,进一步计算水深空间分布和库容量,在此基础上,根据鄱阳湖都昌水文站观测水位,计算鄱阳湖水位-面积曲线和水位-库容曲线。结果表明:鄱阳湖水位存在高水位时空间一致性,低水位时水位存在较大的空间差异,湖泊水位差可达到5 m;水位-淹没面积曲线和水位-库容曲线分别可以由对数方程和二次曲线方程拟合。     

基于MIKE Flood的中小河流溃堤洪水演进数值模拟

针对水文资料缺乏的中小河流,以贵溪市罗塘河下游段为例,应用MIKE软件对河流溃堤洪水演进进行了研究。采用瞬时单位线法推求断面各频率的设计洪水,并将其作为洪水演进模型的输入;利用MIKE软件建立了贵溪市罗塘河下游段的一、二维耦合水动力模型,对该河下游段溃堤洪水演进过程进行了模拟;通过模拟分析,得到了溃口流量过程和堤防保护区洪水淹没过程。研究成果可为中小河流洪水风险分析和灾害损失评估提供技术支撑。     

太湖流域大尺度洪涝淹没仿真模型的建立及应用

利用DEM数据及GIS空间分析技术构建洪涝淹没分析模块,将圩区概化为"零维调蓄单元",实现圩区的精细化模拟,与细化后的太湖流域水文水动力学模型耦合,建立能够可靠模拟太湖流域洪涝淹没状态的数学模型.选择2016年流域性暴雨洪涝资料进行模拟验证,与代表站实测水位及实际洪涝灾情分布对比表明,构建的洪涝淹没仿真模型可靠有效.针...     

蒙洼蓄滞洪区洪水淹没数值模拟

蓄滞洪区是我国江河防洪体系中重要的组成部分。蒙洼作为淮河中游一个重要的蓄洪区，在淮河洪水调度中发挥着至关重要的作用。采用二维非恒定流不规则网格模型，模拟蒙洼蓄洪区内洪水淹没过程，分析蓄洪区内洪水风险，并采用2003年淮河大洪水的实测资料，对模型进行验证。结果表明，该模型能较好地模拟蒙洼蓄洪区洪水淹没过程，可用于蒙洼蓄洪区的规划、建设、管理，乃至整个淮河流域的洪水预报。     

平原感潮河网区域城市洪涝分析模型研究

为开展平原感潮河网区域城市的洪涝分析,综合考虑了该类型区域河流密度大、具有城市的特殊下垫面以及市政排水对洪涝的影响等特点。以城市主干河流、堤防等交汇包围的区域为单元提出了河网排涝单元模型,以排水分区为单元按照其排水能力建立了排水概化模型,并与模拟主干河道和道路、模拟地面的洪水演进模型耦合,建立了平原感潮河网区域城市洪涝分析模型。以上海市浦西防洪保护区为例,开展了上游河道洪水、风暴潮及区域降雨和防洪工程调度综合影响下的洪涝分析。结果表明,黄浦公园等站潮(水)位过程与实测基本一致,苏州河、淀浦河、西大盈港等河流发生漫溢,与实际情况基本相符。研究成果对平原河网地区城市洪涝模拟具有参考价值。     

英国的洪水风险管理

为了减少洪水造成的破坏和损失，近年来世界各国的洪水管理已从单一的防洪工程向洪水风险管理转变。除了能进行有效的洪水防御外，洪水风险管理还被认为是维持生物多样性、河流及海岸生态系统的重要手段。回顾了英国的洪水风险管理及其组成体系，并分析讨论了未来可能面临的问题及应对措施。结果表明，随着全球气候变化及社会经济发展，洪水发生的频率及其影响正在增加。因此，如何全面综合考虑降雨、径流、河流、洪泛区以及人类活动、社会经济规划、发展和管理等诸多因素是实施洪水风险管理面临的重要课题。     

洪水风险快速分析技术方法研究进展

在防汛应急管理中,由于水情的复杂性和多变性,洪水风险分析方案存在不确定性和时变性,针对变化的水雨情数据对洪水风险要素进行快速分析是降低洪灾损失的有效手段。总结可用于洪水风险快速分析的各类技术与方法,通过梳理不同建模方式和风险要素识别模式,对洪水风险快速分析技术方法的原理展开了研究。在此基础上,对比分析了各类方法的优势和局限性,并对其技术特点和适用条件进行了深入探讨。最后,对洪水风险快速分析方法的应用前景进行了展望。分析认为:常用的水面高程推算法和水动力模型法仍有重要利用价值;基于元胞自动机思想的建模方法值得进一步研究和推广应用;基于遥感与GIS技术的淹没分析为大范围洪水灾情的快速评估提供了高效的技术手段。     

永定新河河口风暴潮对其右堤防洪保护区洪水风险影响分析

依托全国重点地区洪水风险图编制工作,以永定新河右堤防洪保护区为研究对象,采用MIKE 21/3 Coupled Model FM软件建立风暴潮模型进行洪水演进计算,分别对防洪保护区内遭遇100年一遇、200年一遇风暴潮情景下的淹没水深、范围、流速、历时等洪水风险要素进行分析,估算了由此产生的居民财产、农林牧渔、工商企业、交通运输、水利设施等方面的直接损失。结果显示,永定新河河口遭遇100年一遇风暴潮时,洪水淹没面积20.69 km~2,其中耕地淹没面积0.41 km~2,居民地淹没面积7.46 km~2,受影响人口2.05万人,受影响GDP达235.13亿元。永定新河河口遭遇200年一遇风暴潮时,洪水淹没面积增加17.79 km~2,耕地淹没面积增加1.66 km~2,居民地淹没面积增加3.77 km~2,受影响人口4.18万人,受影响GDP达630.10亿元。各方案洪水损失估算中,工业产值损失所占比重最大,约占65%,其次是商贸业主营收入,约占24%,其余指标在总损失中所占比例均较小。研究成果能够为区域洪水风险管理、防灾避险预案制定及防洪(潮)调度决策提供技术参考。     

基于AHP和GIS的曹江上游小流域山洪灾害风险区划

为了提高山洪灾害防治管理的针对性,在小流域山洪灾害资料收集的基础上,选取了历年最大6 h暴雨均值、高程标准差、河网密度、土壤类型4个危险性因子和人口密度、人均GDP、土地利用类型3个易损性因子,以层次分析法(AHP)计算各因子权重,通过GIS空间叠加分析,对曹江上游小流域进行了山洪灾害风险区划。由风险区划图可知,曹江上游小流域山洪灾害高—次高风险区主要分布在人口较密集、经济较发达的沿河谷低洼区。通过与历史山洪灾害点的对比验证,证明风险区划结果精度较高,可为本区域的山洪灾害风险识别提供科学依据。     

Applicability of the flood‐pulse concept in a temperate floodplain river ecosystem: thermal and temporal components

Annual growth increments were calculated for blue catfish (Ictalurus furcatus) and flathead catfish (Pylodictis olivaris) from the lower Mississippi River (LMR) to assess hypothesized relationships between fish growth and floodplain inundation as predicted by the Flood‐Pulse Concept. Variation in catfish growth increment was high for all age classes of both species, and growth increments were not consistently related to various measures of floodplain inundation. However, relationships became stronger, and usually direct, when water temperature was integrated with area and duration of floodplain inundation. Relationships were significant for four of six age classes for blue catfish, a species known to utilize floodplain habitats. Though similar in direction, relationships were weaker for flathead catfish, which is considered a more riverine species. Our results indicate the Flood‐Pulse Concept applies more strongly to temperate floodplain‐river ecosystems when thermal aspects of flood pulses are considered. We recommend that future management of the LMR should consider ways to ‘recouple’ the annual flood and thermal cycles. An adaptive management approach will allow further determination of important processes affecting fisheries production in the LMR. Copyright © 2006 John Wiley & Sons, Ltd.