Bibliometric Analysis of Global Research Progress on Coastal Flooding 1995–2016

Global research progress on coastal flooding was studied using a bibliometric evaluation of publications listed in the Web of Science extended scientific citation index. There was substantial growth in coastal flooding research output, with increasing publications, a higher collaboration index, and more references during the 1995–2016 period. The USA has taken a dominant position in coastal flooding research, with the US Geological Survey leading the publications ranking. Research collaborations at institutional scales have become more important than those at global scales. International collaborative publications consistently drew more citations than those from a single country. Furthermore, coastal flooding research included combinations of multi-disciplinary categories, including ‘Geology' and ‘Environmental Sciences & Ecology'. The most important coastal flooding research sites were wetlands and estuaries. While numerical modeling and 3 S(Remote sensing, RS; Geography information systems, GIS; Global positioning systems, GPS) technology were the most commonly used methods for studying coastal flooding, Lidar gained in popularity. The vulnerability and adaptation of coastal environments, their resilience after flooding, and ecosystem services function showed increases in interest.

Experimental Study of Overtopping on Sea Dikes and Coastal Flooding Under the Coupled Processes of Tides and Waves

Storm surges are cataclysmic natural disasters that occur along the coasts and are usually accompanied by large waves.The effects of coupled storm surges and waves can pose a significant threat to coastal security.Previous labo-ratory studies on the effects of storm surges and waves on coastal structures have typically utilized steady water levels and constant wave elements.An indoor simulation of the coupled processes of tides and waves is developed by adding a tide generation system to an existing laboratory wave basin to model continuous dynamic tide levels so that tide generation and wave-making occur synchronously in the pool.Specific experimental methods are given,which are applied to further study waves overtopping on artificial sea dikes and coastal flooding evolution under the coupled actions of tides and waves.The results of the overtopping discharge obtained by the test with a dynamic water level are compared with those obtained from steady water level tests and the existing empirical formula.In addition,the impacts of ecological coastal shelterbelts and structures on coastal flood processes and distributions are also investi-gated.The proposed simulation methods provide a new approach for studying the effects of storm surges and waves on coastal areas.The study also aims to provide a reference for coastal protective engineering.

Modeling Integrated Coastal Flood Hazard in Hurricane Season

The manuscript proposed a procedure designed to determine the hazard of total coastal flooding during the impact of hurricanes, which uses in its formulation the combination of river flooding and that caused by marine upwelling, which is multiplied by a density factor of the water that finds an explanation for the effect is shielding and rising of the water level when the currents of both floods collide in the coastal zone. The application of the procedure experimentally in the coastal sector Sevilla, of the municipality Guama province Santiago de Cuba, resulting in the confirmation of areas previously modeled and estimated coastal flooding in the wake of extreme weather events in the study area;in addition to other new areas that confirm the actual visual and instrumental observations not included in previous studies.

Preface for special section on coastal flood risk

Global concerns about changes in the world＇s climate have been well documented. The consequent impacts on coastal cities, agriculture, and coastal mariculture are difficult to quantify, but it is clear that there is a need for both better estimates of future climate and improved forecasting of storms and their impacts.

Integrated Coastal Flood Risk Management as a Means to Build Resilient Communities

There is a clear trend in the increase of damages and loss of lives and livelihoods in coastal areas as a result of rapid increase in coastal populations, and overall socio-economic development in coastal regions resulting in an increase in vulnerability of populations exposed to coastal floods and exposed infrastructure. Coastal flooding as a result of i.e. storm surges are difficult to predict and cannot be prevented, however there are means to apply integrated flood risk management approaches aiming to reduce the impact of coastal floods. A measure of the effectiveness of such approaches is the awareness and response of coastal communities to coastal flood risks. The paper introduces best practices and methods to lower coastal flood risk at the level of provinces, districts and the community level. This includes advances in coastal flood forecasting and early warning practices, improvement of institutional preparedness and integrated flood management practices as well as measures at the community level aiming to strengthen their resilience to coastal floods. The paper provides a showcase for the historical development and achievements to pave ways for the eventual implementation of a pilot project on integrated flood risk management in coastal areas in central Viet Nam.

Deficiency of Healthcare Accessibility of Elderly People Exposed to Future Extreme Coastal Floods:A Case Study of Shanghai,China

Socioeconomic development,subsidence,and climate change have led to high flood risks in coastal cities,making the vulnerable,especially elderly people,more prone to floods.However,we mostly do not know how the accessibility of life-saving public resources for the elderly population will change under future scenarios.Using Shanghai as a case,this study introduced a new analytical framework to fill this gap.We integrated for the first time models of coastal flooding,local population growth,and medical resource supply-demand estimation.The results show that under an extreme scenario of coastal flooding in the year 2050,in the absence of adaptation,half of the elderly population may be exposed to floods,the supply of medical resources will be seriously insufficient compared to the demand,and the accessibility of emergency medical services will be impaired by flooding.Our methodology can be applied to gain insights for other vulnerable coastal cities,to assist robust decision making about emergency responses to flood risks for elderly populations in an uncertain future.

Assessment of the Vulnerability of the Southwestern Coast of Benin to the Risk of Coastal Erosion and Flooding

The coastal zone of Benin is inherited from the last marine oscillations of the Quaternary. A rich and very fragile environment, it presented until the 1960s, a shoreline in dynamic equilibrium over the entire 125 km of coastal line. Since the 1960s, with the construction of important development infrastructures (ports, dams, groins), the Beninese coast is now subject to risks of coastal erosion and seasonal flooding due to the overflow of lagoon water bodies. The present study, based on socio-economic surveys in the communes of Ouidah, Comè and Grand Popo, exposes the extent of coastal risks and socio-economic and environmental damage in the southwestern coastal zone of Benin. The results show that in terms of land, 2.9 ha and 5.7 ha of land have been permanently lost to coastal erosion in the communes of Ouidah and Grand Popo respectively. Similarly, 212 ha of crops of all types were affected by the flooding, including 35 ha destroyed, i.e. 6.67 ha, 11.3 ha in Comè, 4.67 ha Ouidah and 14 ha Grand Popo. Also, 6435 buildings were affected, and 4235 huts were damaged. In addition, working tools, food stocks and other items are counted among the losses recorded by coastal hazards with their corollaries of diseases. The cost of losses and damages in the 08 districts amount to 418,000,000f cfa of which 266,000,000f cfa of damage and 152,000,000f cfa of loss.

Protective behaviors regarding coastal flooding risk in a context of climate change

The physical vulnerability of coastal areas due to rising sea level and the flooding risk consequent,does not guarantee the implementation of protective behaviors by these risk zones’inhabitants.This study aims to establish the link between the willingness to carry out protective behaviors and physical and perceived indicators of vulnerability.A typology of coastal flooding vulnerability,uses various physical indicators and their perceived counterparts which have been collected from 490 inhabitants of Cartagena(Colombia,declared world heritage of humanity by UNESCO in 1984),resident in areas of coastal flooding risks.The item-response theory(IRT)approach has been used.The results reveal that the implementation of protective behaviors is more related to perceived indicators,such as distance to the sea,than to actual physical vulnerability.We observe that physical vulnerability is linked to the intention to carry out protective behaviors.The presence of a defensive structure against coastal flooding could be considered as a visual cue and be a good predictor of the willingness to carry out protective behaviors.On the contrary,people in the most vulnerable situation(single-storey house)do not demonstrate a higher level of willingness to carry out protective behavior,as well of participants who lived in residential buildings which have demonstrated lower level of willingness to carry out such behaviors.Therefore,vulnerability of the house is not seen as a criterion that encourages participants to better protect themselves.

Using Multidisciplinary Analysis to Develop Adaptation Options against Extreme Coastal Floods

Long-term flood risk adaptation and decision making are complex because the future is full of deep uncertainties.Flexibility and robustness can be used to deal with future uncertainty.This study developed an integrated modeling framework that extends previous studies to the spatial domain to assess the future flood risks and the cost and benefit of three adaptation measures for four types of buildings in Shanghai.Real options analysis(ROA)and dynamic adaptive policy pathways(DAPP)were integrated to develop a dynamic adaptation pathway and identify robust adaptation options.The results show that:(1)Sea level rise and land subsidence will significantly exacerbate the flood risks in Shanghai;(2)Among the three flood control measures,wet-floodproofing has the best economic performance in terms of both the net present value and the benefit/cost ratio,followed by dry-floodproofing,and elevation;(3)Dryfloodproofing can be used at the beginning of the future period(2030–2100),and it can be replaced by wet-floodproofing in 2035–2042;the elevation measure also shows good performance at the beginning of implementation,but its performance will decline after 2041–2045;(4)The combined strategy of dry-and wet-floodproofing in 2044–2046and a hybrid strategy combining the three measures should be the optimal solution for reducing the flood risks in 2047–2051.The methodology developed in this study can provide insights for coastal cities to formulate cost-effective and feasible adaptation strategies in a deeply uncertain future.

Flood Vulnerability Assessment Using Satellite Imagery Data

As flood extreme occurrences are projected to increase in intense and frequency due to climate change, the assessment of vulnerability and the identification of the most vulnerable areas, populations, assets and systems are an urgent need. Vulnerability has been widely discussed and several flood projection tools have been developed using complex hydrological models. However, despite the significant contribution of flood projection maps to predicting the impact of potential floods, they are difficult and impractical to use by stakeholders and policy makers, while they have proven to be inefficient and out of date in several cases. This research aims to cover the gaps in coastal and riverine flood management, developing a method that models flood patterns, using geospatial data of past large flood disasters. The outcomes of this research produce a five scale vulnerability assessment method, which could be widely implemented in all sectors, including transport, critical infrastructure, public health, tourism, constructions etc. Moreover, they could facilitate decision making and provide a wide range of implementation by all stakeholders, insurance agents, land-use planners, risk experts and of course individual. According to this research, the majority of the elements exposed to flood hazards, lay at specific combinations between 1) elevation (Ei) and 2) distance from water-masses (Di), expressed as (Ei, Di), including: 1) in general landscapes: ([0 m, 1 m), [0 km, 6 km), [0 m - 3 m), [0 km, 3 km)) and ([0 m - 6 m), [0 km, 1 km)), 2) in low laying regions: ([0 m, 1 m), [0 km, 40 km), [0 m - 3 m), [0 km, 30 km)) and ([0 m - 6 m), [0 km, 15 km)) and 2) in riverine regions: ([0 m, 4 m), [0 km, 3 km)). All elements laying on these elevations and distances from water masses are considered extremely and highly vulnerable to flood extremes.

FLOOD SIMULATION IN THE COASTAL LOWLANDS OF NORTHERN JIANGSU,CHINA

The coastal lowlands in northern Jiangsu Province, China, is characterized by low relief and low water surface gradient in streams. The flooding stages are commonly lower than the high-tide level and the tidal range is relatively small. All these factors prohibit rapid discharge of floodwater and make the flood regimes here extremely sensitive to the sea level rise. The 1991 Plum Rain was examined, when precipitation was significantly higher than normal. The one-dimensional open-channel non-conservative flow model was used to simulate the stream flow in the channel network of studied area. GIS technology was used to delineate the maximum in undated area by analyzing the DEMs.

我国沿海地区城市洪(潮)涝成因及应对策略——以深圳市为例

沿海地区受地理位置、全球气候变化和城市化快速发展等影响,城市洪(潮)涝灾害频发,已成为影响我国沿海地区城市公共安全的突出问题,严重制约经济社会可持续健康发展。根据城市水文循环过程,综合考虑致灾因子、孕灾环境和承灾体等,将沿海地区城市洪(潮)涝成因概括为“先天不足—后天变化”两个方面,并以深圳市为例进行了深入分析。在此基础上,从提高防洪(潮)和排涝能力,协调防洪、除涝、排水标准,科学规划城市发展,充分考虑地下空间竖向设计,全面加强流域统一管理5个方面提出沿海地区城市洪(潮)涝应对策略,为沿海地区城市防洪(潮)、除涝工程体系建设和城市洪(潮)涝风险管理提供支撑。

广东省沿海平原中小河流淹没图编制方法初探

广东省沿海平原中小河流具有比降缓、潮汐影响大、淹没范围广和堤围密集等特点,其淹没图编制至今无统一方法。该文通过Mike21和Arcgis软件,结合河流特性,参考《山丘区中小河流洪水淹没图编制技术指引》,以乌坎河为例探求出一种适用于广东省沿海平原中小河流的淹没图编制方法。该方法具有可操作性强、准确性较高和适用范围较广等特点,为后续广东省沿海平原中小河流淹没图制作提供参考。

深度不确定性下的沿海城市洪涝风险稳健决策: 方法、原理与展望

全球气候变暖、海平面上升背景下,沿海城市极端洪涝事件的发生频率和强度将显著增大,洪涝灾害风险剧增,成为沿海城市安全与发展的严峻挑战。基于深度不确定性的稳健决策(Decision Making under Deep Uncertainty,DMDU)思路,旨在提供长期稳健的决策方案,成为全球沿海城市洪涝风险管理研究的新趋势。该文对比分析了稳健决策、适应路径和期权估值三类主要DMDU方法,基于不确定性、稳健性和适应性剖析了DMDU方法基本原理,提出了DMDU稳健决策的一般性框架。最后,从稳健性与决策目标、政策环境与决策参与以及方法的融合与创新三个方面对DMDU在洪涝风险领域的实践应用进行展望,以期为沿海城市适应气候变化稳健决策提供参考。

台风对近岸复合洪水的影响评估

不同特性的台风在多大程度上导致与强降水和风暴潮相关的近岸复合洪水尚不清楚,为厘清近岸台风事件与复合洪灾的相互关系,以中国东南沿海为研究典型,基于降水和风暴潮数据,分析1980—2019年复合洪水驱动因子依赖性,利用copula统计模型描绘复合洪水回归期,通过定量评估表明台风对复合洪水潜势升级发挥重要作用。研究表明:(1)中国南方沿海地区复合洪水潜力高于北方,降水与风暴潮之间的依赖性是影响复合洪水发生的关键;(2)台风一方面增强极端降水和极端风暴潮之间的依赖性,使广西、广东阳江、浙江沿海复合洪水潜势增加10%~30%,另一方面提高了极端降水和风暴潮的发生边际概率,使闽苏、海南、澳门地区复合洪水概率增加了50%~180%。(3)相对而言,台风诱发的风暴潮比台风诱发的降水更能放大复合洪水潜势;(4)根据灾害损失分析,台风期间复合事件所造成的损失远大于单驱洪水事件。研究成果可为台风对近岸复合洪水的风险决策及防灾规划提供科学依据。

Modeling the Risks of Climate Change and Global Warming to Humans Settled in Low Elevation Coastal Zones in Louisiana, USA

This paper seeks to identify high risk areas that are prone to flooding, caused by sea level rise because of high impacts of global climate change resulting from global warming and human settlements in low-lying coastal elevation areas in Louisiana, and model and understand the ramifications of predicted sea-level rise. To accomplish these objectives, the study made use of accessible public datasets to assess the potential risk faced by residents of coastal lowlands of Southern Louisiana in the United States. Elevation data was obtained from the Louisiana Statewide Light Detection and Ranging (LiDAR) with resolution of 16.4 feet (5 m) distributed by Atlas. The data was downloaded from Atlas website and imported into Environmental Systems Research Institute’s (ESRI’s) ArcMap software to create a single mosaic elevation image map of the study area. After mosaicking the elevation data in ArcMap, Spatial Analyst extension software was used to classify areas with low and high elevation. Also, data was derived from United States Geological Survey (USGS) Digital Elevation Model (DEM) and absolute sea level rise data covering the period 1880 to 2015 was acquired from United States Environmental Protection Agency (EPA) website. In addition, population data from U.S. Census Bureau was obtained and coupled with elevation data for assessing the risks of the population residing in low lying areas. Models of population trend and cumulative sea level rise were developed using statistical methods and software were applied to reveal the national trends and local deviations from the trends. The trends of population changes with respect to sea level rise and time in years were modeled for the low land coastal parishes of Louisiana. The expected years for the populations in the study area to be at risk due to rising sea level were estimated by models. The geographic information systems (GIS) results indicate that areas of low elevation were mostly located along the coastal Parishes in the study area. Further results of the study revealed that, if the sea level continued to rise at the present rate, a population of approximately 1.8 million people in Louisiana’s coastal lands would be at risk of suffering from flooding associated with the sea level having risen to about 740 inches by 2040. The population in high risk flood zone was modeled by the following equation: y = 6.6667x - 12,864, with R squared equal to 0.9964. The rate of sea level rise was found to increase as years progressed. The slopes of models for data for time periods, 1880-2015 (entire data) and 1970-2015 were found to be, 4.2653 and 6.6667, respectively. The increase reflects impacts of climate change and land management on rate of sea level rise, respectively. A model for the variation of years with respect to cumulative sea level was developed for use in predicting the year when the cumulative sea level would equal the elevation above sea level of study area parishes. The model is given by the following equation: y = 0.1219x + 1944.1 with R square equal to 0.9995.

滨海山地城区洪涝治理系统研究与应用

针对以往洪涝治理研究多集中在城市化对径流特性影响分析、洪涝模拟以及洪涝治理系统上层方案等问题,选取具有代表性的珠海滨海山地老城区,分析其山洪入城、内排不畅、海潮倒灌等致涝成因,构建“完善系统、高水高排、低水低排、自排为主、泵排为辅、蓄水利用、挡潮错峰”等举措于一体的高标准、精细化、系统化洪涝治理系统,同时针对山洪水并联调蓄规模、山地截洪沟规模、山水入城后市政雨水管网规模、路面排水过流能力校核以及滨海区闸泵联合调度调洪演算等论证方法进行系统梳理及适应性分析,以期对类似区域洪涝灾害防治提供经验借鉴。

基于MIKE FLOOD的南方滨海新城雨水管网系统评估

针对南方滨海新城降雨集中、雨量大、洪潮影响突出等特点,以深圳市大空港海洋新城南部排水分区为例,运用MIKE FLOOD模型,采用系统性综合思维,耦合城市雨水管网、洪潮遭遇水位以及地形,评估雨水管网在遭遇不同频率降雨时的管内流量、流速以及充满度,并分析淹没出流对雨水管网系统的影响以及地面积水响应。模型结果表明:规划方案雨水管网安全性高,地面积水无明显积水,但设计管网整体富裕度较大,大部分管段充满度较小、流速较大,存在优化空间,该评估方法为滨海地区雨水管网建设提供基本思路。

Modelling the impact of sea-level rise on urban flood probability in SE China

Urban drainage systems in coastal cities in SE China are characterized by often complex canal and sluicegate systems that are designed to safely drain pluvial flooding whilst preventing tidal inundation.However, the risk of coastal flooding in the region is expected to increase over the next 50-100 years, as urban areas continue to expand and sea-levels are expected to rise. To assess the impact of projected sealevel rise on this type of urban drainage system, a one-dimensional model and decision support tool was developed. The model indicated that although sea-level rise represents a significant challenge, flood probability will continue to be most influenced by rainfall. Events that are significant enough to cause flooding will most likely be minimally impacted by changes to the tidal frame. However, it was found that a sea-level rise of up to 1.2 m by 2010 would result in increased drainage times and higher volumes of over-topping when flooding occurs.

Geomorphology of the Boao coastal system and potential effects of human activities-Hainan Island,South China

The Boao coastal system along the eastern coast of Hainan Island is a dynamic delta-tidal inlet-barrier formed during the late Holocene. The delta developed inside a shallow lagoon barred by a sandy barrier with a narrow, shallow tidal inlet opening. Two major distributary channels separated by small islands characterize the delta. The lagoon is silting up receiving and trapping sediments from both the river and, in minor measure during storms, through the tidal inlet opening and barrier washovers. The barrier at the tidal inlet is highly dynamic and changes its form, accreting (migrating spit) against the inlet during fair-weather conditions and being eroded during storms and river floods. The delta has almost completely filled the lagoon and major concerns exist on the effect that ongoing large development plans may have on the environment. These concerns include the effect on floods and rate of siltation once banks of the islands have been stabilized and floodwater and sediment load are impeded from spreading over the lowlands, and the effect of increasing pollutant loads from the new facilities on the ecosystems of the increasingly restricting lagoon water and on the seashores.