Rebuild, Retreat, or Resilience: Can Taipei Plan for Resilience?

Taiwan is ranked as the country most exposed to multiple hazards (The World Bank 2005). Taipei City is the capital city as well as the economic and political center of Taiwan. The United Nations report World Urbanization Prospects: The 2011 Revision places Taipei City third on the list of the worldâ??s top 10 urban areas exposed to three or more natural hazards, with the highest risk of cyclones, floods, and landslides. In order to gauge the vulnerabilities and damages of Taiwan and Taipei City, this research creates a natural disaster density indicator (NDDI) to conduct a comparative study of Taiwan, Japan, China, U.S.A., U.K., France, and the Netherlands over the past three decades. The results indicate that Taiwan has both the highest disaster occurrence and highest death toll among these seven countries. The Taipei case study, a chronology of policies implemented to prevent flooding, explains that costly engineering structures, rebuilding, and fortification against floods eventually created a false sense of security, which has encouraged more intensive residential and commercial developments in flood-prone areas, and led to a higher level of vulnerability. This research further simulates and evaluates the vulnerabilities of population, land value, properties, GDP, and critical facilities in three scenarios: heavy rainfall, typhoon conditions, and extreme weather rainfall, through the technology of Geographic Information System (GIS) by using ArcMap 10.2.2 software. The results indicate 40% of Taipei City is located in flood risk areas in an extreme weather scenario. This percentage is higher than other global cities such as Londonâ??s 15%, Tokyoâ??s 10%, and New York Cityâ??s 25%. Based on the 10% of total flooding areas above 0.5 meter, the vulnerable population is estimated at 200,000 people, or 7% of the total population. The GDP impact will be more than $28 billion. More than$67 billion of land value is vulnerable. A least one million subway passengers will be impacted each day. There is little evidence that the urban poor are particularly vulnerable to floods. On the contrary, some neighborhoods with high income households face a higher risk of floods. Very few medical centers, oil and gas stations, and electrical power substations are located in flood-prone areas, but, a large number of public schools, administrative buildings, and major subway stations are susceptible. Additionally, the likelihood analysis of flooding in an extreme weather rainfall scenario concludes that the possibility will be five times that of the existing assumption with a flood in every 200 years. Thus, Taipei Cityâ??s infrequent once-in-two-century floods are likely to occur more frequently. Further, the 1% of Taipei metropolitan region flooding above 1 meter will possibly cost up to $ 1.5 billion in damages. Therefore, in the future, rather than strengthening and rebuilding costly structures, Taipei should focus on land-use and environmental planning for resilience. Urban policies should include environmentally responsible development in the face of continued population and economic growth, and being resilient regarding natural disasters. Most important is the need of a strong political commitment and leadership to initiate and implement urban policies toward resilience. In doing so, resilience can be achieved in Taipei

An Incremental Intervention in Jakarta: An Empowering Infrastructural Approach for Upgrading Informal Settelments

Incrementalism is a growing movement within multiple design disciplines that approaches design with sustainable, social, and resilient aims structured around participatory, infrastructural, and phased approaches to design. Carefully considered structural and independent infrastructural frameworks allow infill and accretion according to the demands and needs of individuals and communities. This paper outlines the theories, case studies, and conditions driving incrementalism. My research has informed my project proposal for an incremental upgrade of a slum located in Jakarta using a phased, soft infrastructural, resident facilitated upgrade and development strategy creating new housing units, productive landscapes, and urban form. Incremental development will foster the social aims of my project, while affordably, equitably, and efficiently upgrading the standards of living for slum dwellers within the Waduk Pluit community

An Incremental Intervention In Jakarta: An Empowering Infrastructural Approach For Upgrading Informal Settlements

Incrementalism is a growing movement within multiple design disciplines that approaches design with sustainable, social, and resilient aims structured around participatory, infrastructural, and phased approaches to design. Carefully considered structural and independent infrastructural frameworks allow infill and accretion according to the demands and needs of individuals and communities. This paper outlines the theories, case studies, and conditions driving incrementalism. My research has informed my project proposal for an incremental upgrade of a slum located in Jakarta using a phased, soft infrastructural, resident facilitated upgrade and development strategy creating new housing units, productive landscapes, and urban form. Incremental development will foster the social aims of my project, while affordably, equitably, and efficiently upgrading the standards of living for slum dwellers within the Waduk Pluit community

Density and disasters: economics of urban hazard risk

Today, 370 million people live in cities in earthquake prone areas and 310 million in cities with high probability of tropical cyclones. By 2050, these numbers are likely to more than double. Mortality risk therefore is highly concentrated in many of the world’s cities and economic risk even more so. This paper discusses what sets hazard risk in urban areas apart, provides estimates of valuation of hazard risk, and discusses implications for individual mitigation and public policy. The main conclusions are that urban agglomeration economies change the cost-benefit calculation of hazard mitigation, that good hazard management is first and foremost good general urban management, and that the public sector must perform better in generating and disseminating credible information on hazard risk in cities.Banks&Banking Reform,Environmental Economics&Policies,Hazard Risk Management,Urban Housing,Labor Policies

도시홍수 저감을 위한 근거기반 계획 : 서울시를 중심으로

학위논문 (석사) -- 서울대학교 대학원 : 농업생명과학대학 생태조경·지역시스템공학부(생태조경학), 2021. 2. 강준석.최근 기후변화로 인해 발생되고 있는 사회/경제적 피해는 급속히 증가하고 있다. 기후변화로 인한 2차적 피해로는 폭염, 홍수 등이 있다. 그중에서 극한 강우는 도심지역에 큰 피해를 발생시키고 있다. 대표적으로는 2011년 발생한 집중호우 등이 있는데, 당시에는 최대 110.5 mm/hr의 기록적인 강수가 내렸다. 현대 도시에서 발생하는 홍수의 대부분 원인은 불투수성 포장면의 급격한 증가와 내수배제 불능, 물순환 시설 부재 등의 원인이 있다. 기상청에서 제공하는 기후변화 시나리오에 따르면, 향후 100년간 도시의 평균 강수량은 줄어들 것으로 파악된다. 하지만, 일시에 폭우가 내리는 빈도가 증가하고 국지성 피해가 뚜렷하게 발생할 것으로 판단된다. 현재 상태의 기반시설들에 보수나 방어기술이 수립되지 않으면, 그 피해는 상당할 것으로 판단된다. 이에 본 연구는 총 세 가지 연구 목표를 수립하여 수행하였다. 첫 번째, 기상청에서 제공하는 기후변화 시나리오(RCP 4.5/RCP 8.5)로 인해 발생할 수 있는 향후 80년(2020년-2100년)의 도시 홍수 피해량을 정량적으로 분석한다. 두 번째, 정량적으로 분석된 피해량에 기반한 재해 저감 시설을 선정하고, 재해의 저감량을 분석한다. 이를 통해 근거 기반(Evidence-Based Planning)의 시설배치 및 설계한다. 재해 저감 시설은 미래 세대가 지속적으로 사용할 수 있는 친환경(Eco-Friendly) 시설물을 선정하였다. 세 번째, HCFD (Hazard Capacity Factor Design) 모델의 개발을 통해, 향후 변화할 수 있는 시설물들의 용량과 성능에 대해 정량적으로 분석한다. HCFD 모델은 저감 기술을 유지하는 방법을 고려하는데 사용된다. 이러한 목표를 달성하기 위해서 방어 기술로 총 세 가지를 도입하였다. 저류조, 투수성 포장 그리고 생태수로가 이에 해당한다. 저류조의 경우, 환경부에서 지정하고 있는 법령을 참고하여 도입 가능한 용량을 파악하였다. 투수성포장과 생태수로는 법령으로 명확히 규정하는 설계 지침이 없기에, 타 연구 보고서를 참고하였다. 각 기술들의 도입 규모를 산정하기 위해서 Arc-GIS ArcHydro Plug in을 사용하였고 Watershed를 분석하였다. Watershed에 영향을 미치는 범위를 파악하기 위해서 기후변화시나리오에서 제공하는 강수량을 시간 단위로 분석하였고, 이를 위해 Huff Curve 공식을 사용하였다. 위에서 언급된 세 가지 기술은 빗물의 저장 용량을 증가시켜 홍수 완화에 기여할 것으로 판단된다. 세 가지 기술을 모두 도입하였을 때 2050년과 2060년에는 RCP 8.5 시나리오의 모든 홍수피해를 저감할 수 있을 것으로 판단된다. 2070년 이후에는 유출이 발생할 것으로 분석되지만, 적응 기술을 통해 홍수를 크게 줄일 수 있을 것으로 예측된다. 본 연구 논문에서는 10년 단위의 홍수와 적응량을 산정하였지만, 추후 후속 연구에서는 1년 단위의 분석이 실시되어야 할 것으로 판단된다. 또한 저류조 내부에 퇴적되는 비점오염원의 청소 시기가 산정되었습니다. 저류조의 경우 MOUSE 회귀 분석을 통해 내부에 축적된 비점오염원 제거 시기를 산정하였다. 빗물 저류조 내부 관리는 크게 주의단계, 일반단계, 안전단계로 지방자치단체를 구분하였다. 주의단계에 해당하는 지방자치단체는 9개, 일반단계에 해당하는 지방자치단체는 10개, 안전단계에 해당하는 지방자치단계는 5개가 해당한다. 이 연구의 결과를 통해 도출된 결론 및 의의는 세 가지로 요약된다. 첫째, 본 연구는 기후변화 시나리오에 따라 발생할 수있는 홍수 가능성을 10년 주기로 분석했다.RCP 8.5 시나리오와 RCP 4.5 시나리오 모두 2070년 이후에 빈번한 홍수의 추이를 볼 수 있었다. RCP 8.5 시나리오의 2090년에 강수량이 가장 많을 것으로 예상된다. RCP 4.5 시나리오 2100년의 경우, 최대 690 mm, 시간당 강수량은 238 mm까지 내릴 것으로 판단된다. 두 번째, 본 연구 논문은 각 기술의 용량을 자치구별로 분석하였다. 본 연구에서 가정한 설치 규정에 따르면 서울시 전역에 설치할 수 있는 빗물 저류조의 부피는 776,588 m³, 투수성 포장은 89,049 m³, 생태수로는 81,986 m³이다. 각 지방자치단체가 두 가지 기술만을 적용하였을 때 효율적인 조합을 제안한 것은 본 연구가 가지는 중요한 의의입니다. 셋째, 각 재해저감 기술로 저감할 수 있는 유출량을 정량화했습니다. 이 연구는 지역 차원의 분산적 형태의 홍수가 더 자주 발생하고, 재난 저감 기술의 정량적 효과를 분석하였다는데 의의가 있다. 본 연구의 한계는 네 부분으로 나눌 수 있다. 첫 번째 한계는 기후변화 시나리오에 대한 불확실성이다. 탄소 배출량이나 시나리오의 변화는 강수량 값을 크게 변경할 수 있기 때문에 오류가 적은 시나리오를 사용하면 향후 연구가 더 중요한 연구로 발전할 것으로 판단된다. 최근 기후변화 시나리오의 불확실성을 줄일 수 있는 연구가 활발히 진행 중이기 때문에, 첫 번째 한계점을 보완한 후속연구가 진행될 것이라 판단된다. 두 번째 한계는 RCP 4.5 / RCP 8.5 시나리오가 10년의 빈도로 수행되었다는 것이다. 세 번째 한계점은 사회 변화 요인이 반영되지 않았다는 것 입니다. 네 번째는 검증의 한계입니다. 본 연구에서는 서울시의 유출수를 계산하기 위해 산술 방정식과 GIS Arc-hydro를 사용하였다.추후 SWMM 등의 홍수 해석 프로그램을 활용하여 추가적인 검증이 되어야 한다. 따라서, 위의 네 가지 한계를 극복하기 위해 후속 연구가 수행되어야 할 것으로 판단된다. 특히 첫 번째 문제점인 기후변화 시나리오의 불확실성 한계점은 후속되는 세 가지 한계점을 발생시키기에, 필수적으로 해결되어야 한다.The social and economic damage caused by climate change has increased rapidly over the last several decades, with increasing instances of heat waves, floods, and extreme rainfall. Of these, the damage caused by extreme rainfall is still ongoing, and more extreme rainfall is expected in Korean Peninsula in the future. There was up to 110.5 mm/hr of rainfall in Seoul, which caused 69 casualties and approximately USD 27.6 million in economic damage. Most of the causes of flooding in modern cities include a sharp increase in non-permeable packaging surfaces and a lack of water circulation facilities. According to climate change scenarios provided by the Korea Meteorological Administration, the average rainfall in cities over the next 100 years is expected to decrease. However, it is predicted that future instances of heavy rain will occur in the future, causing large amounts of local damage. If the current state of infrastructure is not equipped with repair or mitigating technologies, the damage will be significant. This study was conducted based on the following three objectives. First, to quantitatively analyze urban flood damage over the next 80 years (2020-2100) that could be caused by the climate change scenario provided by the Korea Meteorological Administration. Second, this study was selected disaster mitigation facilities and analyzed their impact on disaster mitigation. It also arranges and designs facilities based on an evidence-based planning. Sustainable facilities were selected by introducing eco-friendly facilities for future generations as mitigate technologies. Third, through the development of the HCFD (Hazard Capacity Factor Design) model, the capacity and performance of the facilities that may change in the future were analyzed. HCFD model was used to consider ways to maintain mitigating technologies. In order to achieve these goals, a total of three mitigating technologies have been installed. This includes water tanks, permeable pavement, and ecological waterways. In the case of water tanks, the capacity was calculated by referring to the statutes designated by the Ministry of Environment. Also, an Arc-GIS ArcHydro Plug-in was used to calculate the scale of each technology and watershed was analyzed. The precipitation provided by the climate change scenario was analyzed on an hourly basis to determine the extent to which watershed affects it, and the Huff dimensionless curve was used for this purpose. These three mitigating technologies can contribute to flooding by increasing the storage capacity of rainwater. This study suggests that all floods can be reduced by RCP8.5 in 2050, 2060. Although there will be run-off after 2070, it is analyzed that technology will significantly reduce the volume of the flood. It is deemed that a one-year analysis should be conducted in consideration of the maintenance aspects in the future. Furthermore, removal timing of the non-point source pollutant was calculated. In the case of water tanks, the amount of non-point source pollutant accumulated inside and the removal timing were calculated through MOUSE regression analysis. Internal management of water tank is classified into caution stage, general stage and safe stage. There were nine local governments that corresponded to the caution stage, ten local governments of general stage and five local governments of safe stage. There are three main conclusions drawn from the results of this study. First is that the possibility of flooding that could occur according to climate change scenarios was analyzed at a 10-year frequency. Both the RCP 8.5 scenario and RCP 4.5 scenario showed frequent flooding after 2070. For the RCP 8.5 scenario, it is predicted that the year 2090 has the highest amount of precipitation. However, for RCP 4.5 scenario 2100, the maximum daily rainfall is approximately 690 mm, with hourly precipitation of 238 mm. The second is that capacity of each technology was analyzed. According to the installation rules assumed in this study, the volume of water tanks that can be installed throughout the Seoul Metropolitan Government is 776,588 m³, permeable pavement is 89,049 m³, ecological waterway is 81,986 m³. It is siginificant that each local government has suggested an efficient combination of two technologies. Third, the amount of runoff that can be reduced by each mitigating technology was quantified. This study has identified that flooding at the local level will be more frequent and is meaningful in analyzing the quantitative effects of disaster mitigation technologies. Besides, when each local government installed flood mitigation technology in the future, quantification data would be provided to ensure optimized decision making for each situation. The limitations of this study can be diagnosed by dividing them into four parts. The first limitation is uncertainty about climate change scenarios. Since changes in carbon emissions or scenarios can significantly change precipitation values, it is believed that future studies will develop into a more significant study if a scenario with fewer errors is used. The second limitation is that the study was conducted at a frequency of 10 years, as both RCP4.5 / RCP8.5 scenarios were analyzed daily. Third, social change factors are not reflected. Fourth is the limitation of verification. In this study, an arithmetic equation and GIS Arc-hydro were used to calculate the run-off in the Seoul Metropolitan Government. The most ideal method to verification is to compare the results with other software. The reliability of this study can be improved by comparing the amount of runoff before applying technologies using programs such as SWMM, STORM, and MUSIC. Future studies, therefore, should be carried out to overcome the above four limitations. In particular, uncertainty problem of the climate change scenario should be solved.Chapter 1. Introduction 1 1.1 Background 1 1.2 Objectives 5 1.3 Scope 6 1.4 Definition of Floods 8 1.5 Vulnerability 11 Chapter 2. Literature Review 14 2.1 Overview 14 2.2 Policy Review 19 2.3 Types of Defense Technologies 21 2.4 Types of Analysis Programs 33 2.5 Target Site 37 2.6 Climate Change Scenarios 38 Chapter 3. Methodology 41 3.1 Hydrologic Analysis 41 3.2 Application of Mitigation Technology and Estimation of flood damage 46 3.3 Calculation of Current Rainfall Capacity and Run-off 48 3.4 Estimation of Hourly Precipitation in Climate Change Scenarios (RCP 8.5/RCP 4.5) using the Huff curve 51 3.5 The Concept of HCFD (Hazard Capacity Factor Design) Model for observing Future Ability Changes of Facilities 53 Chapter 4. Results 56 4.1 Site Analysis 56 4.2 The 10-year frequency flood damage analysis 65 4.3 Variation of the flooded area after application of disaster mitigating technology 71 4.4 Amount of non-point pollutant deposits in the water tank and maintenance time using the MOUSE regression equation 86 Chapter 5. Summary and Conclusions 94Maste

Losses Associated with Secondary Effects in Earthquakes

The number of earthquakes with high damage and high losses has been limited to around 100 events since 1900. Looking at historical losses from 1900 onward, we see that around 100 key earthquakes (or around 1% of damaging earthquakes) have caused around 93% of fatalities globally. What is indeed interesting about this statistic is that within these events, secondary effects have played a major role, causing around 40% of economic losses and fatalities as compared to shaking effects. Disaggregation of secondary effect economic losses and fatalities demonstrating the relative influence of historical losses from direct earthquake shaking in comparison to tsunami, fire, landslides, liquefaction, fault rupture, and other type losses is important if we are to understand the key causes post-earthquake. The trends and major event impacts of secondary effects are explored in terms of their historic impact as well as looking to improved ways to disaggregate them through two case studies of the Tohoku 2011 event for earthquake, tsunami, liquefaction, fire, and the nuclear impact; as well as the Chilean 1960 earthquake and tsunami event

Estimating the economic viability of long-term investment in flood protection: Case study of the Natorigawa River

departmental bulletin pape

An Approach to Developing a Spatio-Temporal Composite Measure of Climate Change-Related Human Health Impacts in Urban Environments

Introduction: Rapid population growth along with an increase in the frequency and intensity of climate change-related impacts in costal urban environments emphasize the need for the development of new tools to help disaster planners and policy makers select and prioritize mitigation and adaptation measures. Using the concept of the resilience of a community, which is a measure of how rapidly the community can recover to its previous level of functionality following a disruptive event is still a relatively new concept for many engineers, planners and policy makers, but is becoming recognized as an increasingly important and some would argue, essential component for the development and subsequent assessment of adaptation plans being considered for communities at risk of climate change-related events. The holistic approach which is the cornerstone of resilience is designed to integrate physical, economic, health, social and organizational impacts of climate change in urban environments. This research presents a methodology for the development of a quantitative spatial and temporal composite measure for assessing climate change-related health impacts in urban environments. Methods: The proposed method is capable of considering spatial and temporal data from multiple inputs, relating to both physical and social parameters. This approach uses inputs such as the total population density and densities of various demographics, burden of diseases conditions, flood inundation mapping, and land use change for both historical and current conditions. The research has demonstrated that the methodology presented generates sufficiently accurate information to be useful for planning adaptive strategies. To assemble all inputs into a single measure of health impacts, a weighting system was assigned to apply various priorities to the spatio-temporal data sources. Weights may be varied to assess how they impact the final results. Finally, using spatio-temporal extrapolation methods the future behavior of the same key spatial variables can be projected. Although this method was developed for application to any coastal mega-city, this thesis demonstrates the results obtained for Metro Vancouver, British Columbia, Canada. The data was collected for the years 1981, 1986, 1991, 1996, 2001, 2006 and 2011, as information was readily available for these years. Fine resolution spatial data for these years was used in order to give a dynamic simulation of possible health impacts for future projections. Linear and auto-regressive spatio-temporal extrapolations were used for projecting a 2050’s Metro Vancouver health impact map (HIM). Conclusion: Results of this work show that the approach provides a more fully integrated view of the resilience of the city which incorporates aspects of population health. The approach would be useful in the development of more targeted adaptation and risk reduction strategies at a local level. In addition, this methodology can be used to generate inputs for further resilience simulations. The overall value of this approach is that it allows for a more integrated assessment of the city vulnerability and could lead to more effective adaptive strategies