Today, climate change imposes enormous challenges on a global scale. The interactions of the balances between the need for development, population growth, massive urbanization generate a negative impact on the presenc...Today, climate change imposes enormous challenges on a global scale. The interactions of the balances between the need for development, population growth, massive urbanization generate a negative impact on the presence of these climate changes. One of the direct consequences of these changes is the phenomenon of flash floods, a phenomenon that hit the city of Jeddah (city located in west of Saudi Arabia) twice, one in 2009 and the other in 2011, causing significant human and material damage. Floods are considered as a direct result of the combination of extreme weather and hydrological phenomena;in most cases, the magnitude of these floods is magnified by anthropogenic factors, which increases the risk. According to the risk triangle, risk is defined as a probabilistic function that depends on three essential elements: exposure, vulnerability and hazard. If any of these three elements undergo growth the risk also does so and vice versa. Exposure and vulnerability will depend on the presence of human activities in the study area. This study is conducted on the Wadi Goss watershed as it was one of the most violent basins during the 2009 and 2011 floods. Indeed, we present in this study the extent of the urban extension in the Wadi Goss watershed, since 1984 to days and this by the using Landsat images. Given the nature of the study area, we present a method based on the calculation of various indices followed by a classification operation in order to define the urbanized zones inside the Wadi Goss watershed and then estimate the urban sprawl inside the watershed. We also present in this paper, the characteristics of the watershed as well as the evolution of the urbanized areas exposed to the phenomenon of floods and their contribution to the changes of the hydrological behavior of the basin, and to increase the evolution of the risk of the floods. We have shown through this study that the urban footprint has increased from 90 hectares in 1985 to 850 hectares in 2015. This urban footprint represents 12% of the total area of the watershed. Most of the urban evolution was operated on the wadi area with a concentration in the western part of the basin and especially at its outlet.展开更多
To prevent flood disasters, policymakers call for resilient cities which are better able to cope with flood hazards. However, actual adoption of resilience measures in urban planning is still limited, partly because i...To prevent flood disasters, policymakers call for resilient cities which are better able to cope with flood hazards. However, actual adoption of resilience measures in urban planning is still limited, partly because it is not sufficiently clear how and to what extent resilience should and can be enhanced. To develop resilience strategies, information on the current resilience and on the effects of measures should be available. Since cities are complex systems, an assessment of resilience requires the input of different actors. To obtain and combine this input, a comprehensive approach which brings together many actors is required. Furthermore, resilience must be integrated in planning frameworks in order to enhance adoption by city policy makers. Tools which support and structure the contribution of different disciplines and actors will help to obtain information on the current resilience and to develop a shared vision on measures to enhance urban resilience. We illustrate our view with an example on Cork, Ireland.展开更多
对“内涝”和“风险评估”进行关键词检索,以1991—2023年中国知网(CNKI)中文数据库、Web of Science(WOS)核心数据库共2783篇城市内涝风险评估相关文献为基础,采用词频分析、共被引分析、聚类分析等文献计量方法,借助R语言的Bibliomet...对“内涝”和“风险评估”进行关键词检索,以1991—2023年中国知网(CNKI)中文数据库、Web of Science(WOS)核心数据库共2783篇城市内涝风险评估相关文献为基础,采用词频分析、共被引分析、聚类分析等文献计量方法,借助R语言的Bibliometrix包实现数据统计与图谱绘制。结果表明,以内涝风险评估为主题的国内外相关研究近10年呈快速增长趋势,虽然中文文献出现晚于英文文献,但英文文献中,国内研究机构发文量最多;对应国内城市暴雨洪涝灾害发生数量排全球首位,体现出国内城市暴雨内涝灾害影响严重,并已逐渐成为众多学者关注的研究热点;地理信息系统(GIS)是内涝风险评估研究中常用的技术手段,机器学习和遥感技术广泛应用于国际研究,值得国内相关研究学习和借鉴;英文研究热点集中在灾损曲线、脆弱性指标体系和多准则的内涝综合风险分析,而中文研究目前聚焦在基于水文和水力学模型的内涝灾害危险性识别,未来在逐步完善的海绵城市和内涝防治工程建设研究基础上,面向气候变化和韧性城市规划建设的内涝综合风险评估可能会成为新的研究热点。展开更多
Risk governance is a widely used framework in natural and societal risk management research.Risks from natural hazards in urban areas call for the establishment of rigorous and participatory urban risk governance.In t...Risk governance is a widely used framework in natural and societal risk management research.Risks from natural hazards in urban areas call for the establishment of rigorous and participatory urban risk governance.In this study,we examined participatory risk governance(PRG)of flood risk management(FRM)in Seoul,South Korea.We conducted key informant interviews and implemented a survey with citizens,to explore perceptions of flood risks and risk management,and to examine prospects for improving PRG in Seoul.We found a gap between the perceptions of key informants and citizens.Key informants believed that citizens'low awareness of flood risks hinders PRG.Yet our research found that citizens'risk awareness was not low,and risk awareness may not be the main barrier to participation in PRG.Instead,we found that citizens lacked knowledge of FRM actions,and they assigned government bodies a high level of responsibility for FRM,compared to the level of responsibility that citizens assigned to themselves.Moreover,the actors involved in FRM tended not to trust each other,which implies a lack of mutual understanding.To increase the eff ectiveness of PRG,we suggest a polycentric governance structure anchored by a leading actor group,and active promotion of the participation of actors at multiple levels of governance.Communication between government and citizen participants,designed to foster improved understanding and recognition of one another's roles and contributions to FRM,will enhance trust and improve the implementation of PRG in Seoul.展开更多
文摘Today, climate change imposes enormous challenges on a global scale. The interactions of the balances between the need for development, population growth, massive urbanization generate a negative impact on the presence of these climate changes. One of the direct consequences of these changes is the phenomenon of flash floods, a phenomenon that hit the city of Jeddah (city located in west of Saudi Arabia) twice, one in 2009 and the other in 2011, causing significant human and material damage. Floods are considered as a direct result of the combination of extreme weather and hydrological phenomena;in most cases, the magnitude of these floods is magnified by anthropogenic factors, which increases the risk. According to the risk triangle, risk is defined as a probabilistic function that depends on three essential elements: exposure, vulnerability and hazard. If any of these three elements undergo growth the risk also does so and vice versa. Exposure and vulnerability will depend on the presence of human activities in the study area. This study is conducted on the Wadi Goss watershed as it was one of the most violent basins during the 2009 and 2011 floods. Indeed, we present in this study the extent of the urban extension in the Wadi Goss watershed, since 1984 to days and this by the using Landsat images. Given the nature of the study area, we present a method based on the calculation of various indices followed by a classification operation in order to define the urbanized zones inside the Wadi Goss watershed and then estimate the urban sprawl inside the watershed. We also present in this paper, the characteristics of the watershed as well as the evolution of the urbanized areas exposed to the phenomenon of floods and their contribution to the changes of the hydrological behavior of the basin, and to increase the evolution of the risk of the floods. We have shown through this study that the urban footprint has increased from 90 hectares in 1985 to 850 hectares in 2015. This urban footprint represents 12% of the total area of the watershed. Most of the urban evolution was operated on the wadi area with a concentration in the western part of the basin and especially at its outlet.
文摘To prevent flood disasters, policymakers call for resilient cities which are better able to cope with flood hazards. However, actual adoption of resilience measures in urban planning is still limited, partly because it is not sufficiently clear how and to what extent resilience should and can be enhanced. To develop resilience strategies, information on the current resilience and on the effects of measures should be available. Since cities are complex systems, an assessment of resilience requires the input of different actors. To obtain and combine this input, a comprehensive approach which brings together many actors is required. Furthermore, resilience must be integrated in planning frameworks in order to enhance adoption by city policy makers. Tools which support and structure the contribution of different disciplines and actors will help to obtain information on the current resilience and to develop a shared vision on measures to enhance urban resilience. We illustrate our view with an example on Cork, Ireland.
文摘对“内涝”和“风险评估”进行关键词检索,以1991—2023年中国知网(CNKI)中文数据库、Web of Science(WOS)核心数据库共2783篇城市内涝风险评估相关文献为基础,采用词频分析、共被引分析、聚类分析等文献计量方法,借助R语言的Bibliometrix包实现数据统计与图谱绘制。结果表明,以内涝风险评估为主题的国内外相关研究近10年呈快速增长趋势,虽然中文文献出现晚于英文文献,但英文文献中,国内研究机构发文量最多;对应国内城市暴雨洪涝灾害发生数量排全球首位,体现出国内城市暴雨内涝灾害影响严重,并已逐渐成为众多学者关注的研究热点;地理信息系统(GIS)是内涝风险评估研究中常用的技术手段,机器学习和遥感技术广泛应用于国际研究,值得国内相关研究学习和借鉴;英文研究热点集中在灾损曲线、脆弱性指标体系和多准则的内涝综合风险分析,而中文研究目前聚焦在基于水文和水力学模型的内涝灾害危险性识别,未来在逐步完善的海绵城市和内涝防治工程建设研究基础上,面向气候变化和韧性城市规划建设的内涝综合风险评估可能会成为新的研究热点。
基金provided by the University of Arizona School of Geography,Development and Environment,Graduate and Professional Student Council,and Global Change Graduate Interdisciplinary Program。
文摘Risk governance is a widely used framework in natural and societal risk management research.Risks from natural hazards in urban areas call for the establishment of rigorous and participatory urban risk governance.In this study,we examined participatory risk governance(PRG)of flood risk management(FRM)in Seoul,South Korea.We conducted key informant interviews and implemented a survey with citizens,to explore perceptions of flood risks and risk management,and to examine prospects for improving PRG in Seoul.We found a gap between the perceptions of key informants and citizens.Key informants believed that citizens'low awareness of flood risks hinders PRG.Yet our research found that citizens'risk awareness was not low,and risk awareness may not be the main barrier to participation in PRG.Instead,we found that citizens lacked knowledge of FRM actions,and they assigned government bodies a high level of responsibility for FRM,compared to the level of responsibility that citizens assigned to themselves.Moreover,the actors involved in FRM tended not to trust each other,which implies a lack of mutual understanding.To increase the eff ectiveness of PRG,we suggest a polycentric governance structure anchored by a leading actor group,and active promotion of the participation of actors at multiple levels of governance.Communication between government and citizen participants,designed to foster improved understanding and recognition of one another's roles and contributions to FRM,will enhance trust and improve the implementation of PRG in Seoul.
