基于“H-E-V”框架的城市洪涝风险评估研究进展

在全球气候变化与城市扩张的背景下,城市洪涝问题频发并引发严重的社会问题与经济损失。当前城市洪涝管理的主要内容已从工程性防御性措施转向洪涝风险管理,而城市洪涝风险评估又是城市洪涝管理的关键环节。基于此背景,论文首先介绍了IPCC采纳的城市洪涝风险评估框架“危险性(Hazard)—暴露性(Exposure)—脆弱性(Vulnerability)”即“H-E-V”的概念内涵,在此基础上梳理了其危险性、暴露性、脆弱性3大要素的主要研究内容,探讨分析不同研究方法的优缺点。最后提出了城市洪涝风险评估的主要发展趋势及关键问题,主要有以下4个方面：①危险性方面,建立适应于城市地区的耦合型二维洪涝淹没模型是洪涝风险评估要求下的必然趋势;②暴露性分析在大数据及GIS技术支撑下正逐步精细化、动态化;③脆弱性正从早期侧重的物理维度定量评估转向社会、经济、文化、环境等多维度的评估;④此外,气候变化与城市扩张下的多情景城市洪涝风险评估是未来城市洪涝管理的研究热点与难题。     

Using LiDAR-DEM based rapid flood inundation modelling framework to map floodplain inundation extent and depth

Mapping floods is important for policy makers to make timely decisions in regards to emergency responses and future planning. It is therefore crucial to develop a rapid inundation modelling framework to map flood inundation. This study develops an airborne scanning laser altimetry(Li DAR) digital elevation model(DEM) based Rapid flood Inundation Modelling framework(Li DAR-RIM) for assessment of inundation extent, depth, volume and duration for flood events. The modelling framework has been applied to the mid-Murrumbidgee region in the southeast Murray-Darling Basin, Australia for two flood events occurred in December 2010 and March 2012. The inundation extents estimated using this methodology compared well to those obtained from two Landsat ETM+ images, demonstrating suitability and applicability of this method. For testing possibility of larger area application, the framework also uses 30-m resolution shuttle radar topography mission(SRTM)-DEM to replace Li DAR-DEM for the same modelling. The inundation extents obtained by using the SRTM-DEM are smaller than those obtained using the Li DAR-DEM, especially for large flood events. A possible reason is that the river cross sections obtained from the SRTM-DEM are not accurate enough for inundation modelling. The Li DAR-RIM has an advantage for process modelling and scenario modelling under future climatic conditions.     

Comparison of flood hazard assessments on desert piedmonts and playas: A case study in Ivanpah Valley, Nevada

Accurate and realistic characterizations of flood hazards on desert piedmonts and playas are increasingly important given the rapid urbanization of arid regions. Flood behavior in arid fluvial systems differs greatly from that of the perennial rivers upon which most conventional flood hazard assessment methods are based. Additionally, hazard assessments may vary widely between studies or even contradict other maps. This study's chief objective was to compare and evaluate landscape interpretation and hazard assessment between types of maps depicting assessments of flood risk in Ivanpah Valley, NV, as a case study. As a secondary goal, we explain likely causes of discrepancy between data sets to ameliorate confusion for map users. Four maps, including three different flood hazard assessments of Ivanpah Valley, NV, were compared: (i) a regulatory map prepared by FEMA, (ii) a soil survey map prepared by NRCS, (iii) a surficial geologic map, and (iv) a flood hazard map derived from the surficial geologic map, both of which were prepared by NBMG. GIS comparisons revealed that only 3.4% (33.9 km²) of Ivanpah Valley was found to lie within a FEMA floodplain, while the geologic flood hazard map indicated that ~ 44% of Ivanpah Valley runs some risk of flooding (Fig. 2D). Due to differences in mapping methodology and scale, NRCS data could not be quantitatively compared, and other comparisons were complicated by differences in flood hazard class criteria and terminology between maps. Owing to its scale and scope of attribute data, the surficial geologic map provides the most useful information on flood hazards for land-use planning. This research has implications for future soil geomorphic mapping and flood risk mitigation on desert piedmonts and playas. The Ivanpah Valley study area also includes the location of a planned new international airport, thus this study has immediate implications for urban development and land-use planning near Las Vegas, NV.     

城市暴雨内涝综述：特征、机理、数据与方法

建成环境的高空间异质性与致灾过程的复杂性给城市暴雨内涝研究带来巨大的挑战,具体表现为模型代表性不够、计算效率低、基础数据和验证数据匮乏。以机器学习为代表的人工智能技术、高分遥感和互联网大数据的快速发展则为城市暴雨内涝研究提供了新的契机。论文结合人工智能、高分遥感和互联网大数据等新技术发展,从特征、机理、数据与方法4个维度对暴雨内涝的研究现状和发展趋势进行了系统总结,主要结论包括：① 暴雨内涝具有短历时性、空间散布性、连锁性和突变性,其热点呈现空间上的动态迁移特征。② 降雨时空特征和城市化程度决定暴雨内涝灾害的量级,地形条件尤其是微地形则决定发生位置和内涝频率。地形控制作用指数(topographic control index, TCI)对暴雨内涝发生位置具有良好的指示能力。③ 排水管网、高精度地形和不透水面分布是暴雨内涝模拟的关键基础数据;降雨过程的高时空变异性是暴雨内涝近实时预报预警的主要瓶颈,需要充分利用天气雷达观测提高其精准度;互联网众包大数据是获取高空间覆盖度暴雨内涝灾情信息的新途径,但也面临不同类型信息融合、提炼和质量控制的挑战。④ 结合水动力模拟与机器学习可建立兼具物理基础和计算效率的暴雨内涝模拟方法,是实现近实时模拟与快速预报预警的有效途径。     

基于GIS的城市用地布局多情景模拟与方案评价——以江苏省太仓市为例

用地布局一直是城市总体规划中的关键难题,以往的规划方案多凭借规划师的经验判断、简单的图层叠加和有限的公众参与生成。然而新的城乡规划法要求从多角度综合考虑城乡用地布局问题,更加注重规划过程的科学性和准确性,也就特别需要有一种适应多情景分析下的城市用地布局模拟与方案评价方法。文章以江苏省太仓市为例,借助GIS技术的强大空间分析功能,探讨了这种方法的技术流程：① 参考已有的大尺度城市未来模型,结合我国特别是研究区的区域特点,构建一个实用的城市未来模型(Urban Future Model,UFM);② 通过用地评价、战略归纳、情景模拟等步骤,生成若干个可选的用地布局模拟方案;③ 应用多目标达成矩阵法从粮食、生态、灾害等多个角度对这些方案进行综合评价,并根据评价结果选择一个最佳方案作为本轮总规用地布局的规划参考方案。     

Cloudburst floods in mountains: State of knowledge,occurrence, factors of formation

A detailed analysis is made of the current ideas concerning floods of a special type. We examine short-lasting torrential flash floods, one of the most widespread and hazardous natural phenomena in the world characterized by a high rate of development, and by a short duration. It is established that such floods are in a primitive stage of study, which is testified by the fact that there is no general consensus as to what should be treated as a flash flood. It is pointed out that a special term designating them is also absent in many countries. It is determined that the key formation conditions for flash floods include intense short-lasting cloudbursts, the occurrence of a river basin in mountainous regions and a small drainage area; on this basis, it is suggested that they be termed flash floods. It is shown that such floods are of the most widespread occurrence in the northern hemisphere in regions with a temperate and subtropical climate. We suggest the scheme of natural factors for formation of flash floods and their differences from debris flows and floods of other types. It is determined that the main problems of investigating the formation mechanisms and forecasting the aforementioned floods are associated with the small spatiotemporal scale of these phenomena.     

A LiDAR-based flood modelling approach for mapping rice cultivation areas in Apalit,Pampanga

Majority of rice cultivation areas in the Philippines are susceptible to excessive flooding owing to intense rainfall events. The study introduces the use of fine scale flood inundation modelling to map cultivation areas in Apalit, a rice-producing municipality located in the province of Pampanga in the Philippines. The study used a LiDAR-based digital elevation model (DEM), river discharge and rainfall data to generate flood inundation maps using LISFLOOD-FP. By applying spatial analysis, rice cultivation zone maps were derived and four cultivation zones are proposed. In areas where both depth and duration exceed threshold values set in this study, varieties tolerant to stagnant flooding and submergence are highly recommended in Zone 1, where flood conditions are least favorable for any existing traditional lowland irrigation varieties. The study emphasizes that a decline in yield is likely as increasing flood extents and longer submergence periods may cause cultivation areas for traditional irrigated lowland varieties to decrease over time. This decrease in yield may be prevented by using varieties most suitable to the flooding conditions as prescribed in the rice zone classification. The method introduced in this study could facilitate appropriate rice cultivation in flood-prone areas.     

基于树轮地貌学的山洪研究进展

山洪是中国主要的自然灾害之一,严重威胁山区人民生命财产与工程建设安全。针对山洪已发展了多种多样的研究手段,但多集中于过去几十年的时间段内。树轮地貌学方法作为研究历史山洪事件的有效手段之一,在世界范围内被广泛应用。利用树轮中的生长干扰信息,可以对山洪事件进行精确定年,重建无记录或少记录地区内山洪发生的频率、大小和空间分布特征等,根据伤疤的高度或应用水力模型则可以定量重建山洪的流量大小。随着树轮地貌学方法和技术的逐渐成熟,研究趋向于探讨山洪的驱动机制、更大空间尺度山洪的规律性等,具有广阔的应用前景,但是基于树轮的山洪研究工作在国内还未见报道。论文对树轮地貌学应用于山洪研究的发展过程进行了系统回顾,对研究进展进行了简要概述,最后讨论该研究领域的潜力及局限性,以期为在国内进一步开展相关工作提供参考信息。     

A decadal historical satellite data analysis for flood hazard evaluation: A case study of Bihar (North India)

Flood is one of the major recurrent natural disasters faced by the state of Bihar in north India. In the present study the authors assess the severity of flood hazard in Bihar, using 128 decadal historical satellite datasets acquired during different flood magnitudes during 1998 to 2010. The satellite‐based observations have been analysed in conjunction with the hydrological data, for assessing the frequency of inundation, severity of flood hazard and cropped land under flood hazard. This study assesses the spatial distribution of flooding and creation of systematic flood hazard database, which can be analysed from a spatial dimension in GIS. It is observed that about 24.56 lakh ha of the state's area and about 15.85 lakh ha of the cropped area are vulnerable to flood hazard. North Bihar is more vulnerable to flooding; 8 of the 10 areas identified as worst flood‐affected districts lie in this region.     

山洪视角下社区韧性影响因素及其定量分析

山洪灾害具有广泛性、突发性、破坏性等特征,开展山洪易发区的社区韧性评估,从而提高灾害应对能力是当前防灾减灾的前沿热点和难点。论文提出了一套多学科的综合方法：① 利用中介效应明晰了山洪视角下社区韧性评价体系各指标间的定量化传递关系;② 构建了基于决策实验室分析和解释结构模型的耦合数学模型,确定社区韧性影响因素的多级递阶解释结构模型,分析社区韧性的差异化影响因素;③ 采用信息扩散方法,定量分析山洪灾害社区韧性的变化趋势并排序。以粤北山洪易发区为例,从城镇、村落、城乡结合部3种类型社区进行灾害韧性分析。结果表明：山洪视角下的社区韧性指标体系是一个多维度多层次的复杂网络系统,包括环境、社会、心理、制度和信息沟通5个方面;不同类型社区灾害韧性的直接影响因素呈差异化特征,而供排水设施建设和洪灾应急演练为社区韧性的根本影响因素,对增强山洪视角下社区韧性发挥本质性作用;由于调研村落多位于山洪频发区,居民防范灾害、减轻灾害影响的意识较强,村落较城镇和城乡结合社区呈现出更高的韧性。研究可为提升粤北山洪易发区社区韧性及社区防灾减灾能力提供科学参考,该综合分析方法亦可为其他类型灾害的精细化防灾减灾提供支持。     

长沙市防洪建设中若干重要问题探讨

探讨了全国重点防洪城市长沙市防洪建设中的若干重要问题:防洪标准、设计洪水位、防洪大堤高度等的确定;建设方针与程序、整体防洪能力建设、防洪建设与基础设施建设和景观建设协调发展等。长沙设计洪水位的确定应综合考虑以下几个方面:湘江长沙段洪水与其支流和东洞庭湖洪水不存在高标准洪水同期遭遇问题,更不存在同频率洪水遭遇问题;湘江洪水流量与水位关系不是长沙洪水设计的主要依据;而南洞庭湖洪水位顶托和河道槽蓄量减少是影响长沙洪水位高低的动、静态因素。目前,长沙城市堤防设防高度偏高,减少了大堤的稳定性,造成了无效投资,影响了城市景观。防洪工程建设应分期实施、先除险后加固、注重整体防洪能力的提高,并处理好与城市基础设施建设和景观建设的关系。     

基于PGIS的社区洪涝灾害概率风险评估——以福建省泰宁县城区为例

以福建泰宁县城区为例,基于PGIS 和概率（情景）风险分析方法,开展社区尺度的洪涝灾害风险研究。利用1949-2011年13 次历史洪灾资料,计算了洪水的强度-超越概率,得出大于洪峰流量2929.18 m³/s 和洪峰水位281.50 m的年超越概率为1.6%。在此情景下,县城淹没面积达1.3 km²（占总面积31.0%）,最大淹没深度超过3.5 m,最长淹没时间超过10小时,共有1846 幢建筑物（占全部建筑的42.2%）受影响。分别针对受灾区域房屋建筑、住宅室内财产和商户室内财产,建立灾损方程,评估损失价值,并绘制灾损地图。结果表明,洪涝灾害对社区造成的影响显著,有必要制定应急预案,建立早期预警等进行防灾降险。     

Sediment delivery and accumulation in a developed area during coastal floods

The study area is a portion of a coastal community that is adjacent to a salt marsh and tidal creek. The developed area was built upon wetlands, and like the marsh, it floods during spring tides and strong coastal storms. Following floods, little visual evidence of sedimentation is in the built area, prompting the hypothesis that physical characteristics of coastal development limit sediment availability during floods and reduce deposition. Because the area floods from a tidal creek during the same events that lead to inundation of the adjacent high marsh, salt marshes are used as an analogue system for planning this research. Although salt marsh geomorphology is a starting point, people are endogenous actors at this site who influence geomorphic evolution by changing the flow of naturally occurring energy. Suspended sediment levels or deposition were measured during 10 flooding events. Water samples were collected from the tidal creek, at a catchbasin, at another location in the street, and in the Spartina patens marsh. Sediment is found to be delivered to the street in the same quantities and for the same duration as in the salt marsh. Suspended sediment levels are alike throughout the research area. The amount of sediment that accumulates following coastal floods was measured by placing samplers within the street and the marsh. Highly significant differences in sediment accumulation exist between the environments. After a flood event, much less sediment is deposited in the street than in the marsh.     

利用GIS技术实现山洪易泛区地貌学判识的实践探讨--以云南省为例

由于受山区特殊的地貌特征控制，山洪的空间分布广泛而又相对分散，具有发灾突然、空间尺度小、分布数量多、成灾迅速等特点，要在空间上正确表达区域性的山洪泛滥可能的影响范围有相当大的难度。以云南省为例，探讨了以地貌学法为出发点，借助GIS工具提取山洪易泛区范围信息的可行性。山洪易泛范围的判识方法可为区域规划和建设规划人员和工程人员提供有价值的工具。     

Historic fluvial development of the Alpine-foreland Tagliamento River, Italy, and consequences for floodplain management

The fluvial geomorphological development of the Tagliamento River and its flooding history is analysed using historical documents and maps, remote-sensed data and hydrological information. The river has been building a complex alluvial fan starting from the middle part of its alluvial course in the Venetia–Friuli alluvial plain. The riverbed is aggrading over its entire braided length. The transition from braiding to meandering near Madrisio has shifted downstream where the river width determined by the dikes becomes narrower, causing major problems. The flood hazard concentrates at those places and zones where flooding occurred during historical times. Prior to the agrarian and industrial revolution, land use was adjusted to the flooding regime of the river. Subsequent land-use pressure led to a confinement of the river by dikes to such an extent that the flood risk in the floodplain downstream of Madrisio has increased consistently, and represents nowadays a major territorial planning issue. The planned retention basins upstream of the middle Tagliamento will alleviate the problem, but not solve it in the medium and long term. Therefore, fluvial corridors in the lower-middle parts (from Pinzano to the sea) have been identified on the basis of the flooding history in relation to fluvial development during historical times. The result should be used for hydraulic simulation studies and land-use planning.     

基于PGIS的社区洪涝灾害概率风险评估简

以福建泰宁县城区为例,基于PGIS 和概率（情景）风险分析方法,开展社区尺度的洪涝灾害风险研究。利用1949-2011年13 次历史洪灾资料,计算了洪水的强度—超越概率,得出大于洪峰流量2929.18 m³/s 和洪峰水位281.50 m的年超越概率为1.6%。在此情景下,县城淹没面积达1.3 km²（占总面积31.0%）,最大淹没深度超过3.5 m,最长淹没时间超过10小时,共有1846 幢建筑物（占全部建筑的42.2%）受影响。分别针对受灾区域房屋建筑、住宅室内财产和商户室内财产,建立灾损方程,评估损失价值,并绘制灾损地图。结果表明,洪涝灾害对社区造成的影响显著,有必要制定应急预案,建立早期预警等进行防灾降险。     

北京中心城区内涝成因

城市化的发展改变了原始的自然水文循环系统,打破了水量的均衡而导致了城市内涝。本文梳理了应对雨水的基本模式,并总结出与城市规划相关的三方面主要致涝因素——城市土地利用、水系统和基础设施。以北京中心城区为案例,综合考虑城市用地变化过程,从城市基本汇水区单元的视角出发,分析城区内涝程度和上述三方面因素之间的关联规律。结果表明平均坡度、河网密度与城市内涝程度呈线性正相关;耕地比率、林地比率、荒地比率与城市内涝程度呈线性负相关;而不透水表面比率和建设用地比率与城市内涝程度呈指数正相关关系。     

Local flash floods in Central Europe: A case study of Poland

Bryndal, T. 2015. Local flash floods in Central Europe: A case study of Poland. Norsk Geografisk Tidsskrift–Norwegian Journal of Geography. Vol. 69, 288–298. ISSN 0029-1951.

The article focuses on the seasonality, geographical distribution, and hydrometeorological aspects of local flash floods in Poland, in Central Europe. Scientific articles describing local flash flood events were studied and a database of such floods in Poland was developed and analysed. The results revealed that local flash flood events were usually generated by rainfall lasting less than two hours, with a mean intensity in the range 20–80 mm·h^-1. The triggering threshold for local flash floods was P = 20 mm·h^-1. Local flash floods may occur from April to October, with higher frequencies in May, June, and July. The floods usually affect mountain and uplands areas differently to lowland and basins regions, and this might be explained by heavy rainfall distribution and topographical conditions. The maxima of the unit discharge (Qs) describe an envelope curve according to the equation Qs = 47A^-0.4 (where A is the catchment area in km²). The maxima appear very consistent with envelope curves proposed for other inland continental European countries. The authors conclude that local flash floods in Poland are similar to those recorded in inland continental areas of Europe, but differ from the floods in the Mediterranean part of the continent.     

塔里木河流域突发性洪水初步研究

突发性洪水是干旱区河流重要的水文事件，塔里木河流域突发性洪水主要包括暴雨突发性洪水和冰川湖崩决洪水，本文例举了发生在上游支流的两种类型突发性洪水，对其发生、发展进行了比较分析，同时，分析了不同类型不同支流发生的突发性洪水对干流的影响。     

Assessing and mapping human well-being for sustainable development amid flood hazards: Poyang Lake Region of China

Less developed places that are affected by climatic impacts face great challenges to future development. Place-based assessments that look at both the development level and climatic impacts on development are important for understanding the current state of human well-being and generating insights into how to facilitate sustainable development in the future. We carry out an assessment of human well-being in the Poyang Lake Region of China (PLR), using GIS, remote sensing, and socio-economic data. We measure human well-being in three aspects of (i) development level, (ii) exposure of development to flooding, and (iii) sensitivity of development to flooding. Following the United Nations Development Programme's human development index, we examine development through measures of life expectancy, literacy, and income. We first use a digital elevation model and GIS data on levees to map flood hazard in PLR. Based on the flood hazard map, we then derive quantitative measures of exposure and sensitivity of the development in a town to flooding. Our assessment indicates that development in PLR overall is highly exposed and sensitive to flooding. There are significant variations in different aspects of human well-being among the 298 towns in the region. These variations suggest different sustainable development pathways and policy interventions for different places. We discuss the potential usefulness of our approach for other similar places.