Opportunistic Adaptation

Using the Urban Renewal Cycle to Adapt to Climate Change

Polpat Nilubon

• Publisher: CRC Press
• Year: 2021
• eBook ISBN: 9781000425307
• Topic: Biological Sciences
• Subtopic: Environmental Science
• Index: Biological Sciences

Urban climate adaptation currently focusses mainly on hazards but often ignores opportunities which arise in both space and time. Opportunistic Adaptation provides a rationalized approach to mainstream measures for climate adaptation into urban renewal cycles. Adaptation opportunities are identified by projecting the lifespans of urban assets into the future to obtain an operational urban adaptation agenda for the future. Upscaling of the adaptation process is done by synchronizing the end-of-lifecycle of a group of assets to develop adaptation clusters that comprise multiple dwellings, infrastructure as well as public spaces. An extensive catalogue of adaptation measures for different scale-levels ensures flexibility in the type of measures that can be integrated. Sequencing the adaptation measures over long periods of time provides insight and flexibility in the long-term protection standards that can be achieved. By applying a design-centered approach, the potentials of obtaining co-benefits in the urban landscape are maximized. Potentials of clustering of nature-based solutions are being considered which ensures to maximize the delivery of ecosystem services. This research aims to assess \the adaptation potential of Bangkok, based on a case study area (Lat Krabang) by mapping the adaptation opportunities and flood vulnerability. The resulting outputs will contribute to the development of a flexible and inclusive FRM strategy.

Chapter 1

Introduction

1.1 Introduction

Bangkok is one of the World’s most vulnerable megacities to flooding. The big flood in 2011 has made clear that interventions at various spatial levels will be required to make the city more flood resilient. At the grassroots level, communities in Bangkok have been very resilient over the past centuries. Many of those communities are well organized and are engaged in local flood mitigation initiatives. However, this local capacity is slowly disappearing and lacks alignment with interventions taken at city governmental level. It is becoming increasingly evident that interventions to reduce flood risk in Bangkok should be part of a holistic and adaptive strategy in order to deal with future uncertainties such as climate change and economic development. At the same time, Bangkok is a thriving, dynamic city with a huge potential to adapt to changing conditions. However, at present date there is a lack of insight in this potential of the city. This insight is vital to develop an adaptation strategy which combines climate change with socio-economic drivers.

This dissertation aims to get a deeper understanding of the Adaptation Potential (AP) of the city of Bangkok. The AP in this research is directly related to the process of urban renewal as urban renewal provides an opportunity to intervene in the urban fabric, to restore old mistakes and to make adjustments and adapt the buildings and infrastructure to changing flood conditions. This type of intervention is referred to in this dissertation as Opportunistic Adaptation (OA).

The main objective of this dissertation is to explore and further deepen our understanding of OA using renewal cycles of the urban fabric components for the context of Bangkok. In addition, it aims to develop a method which enables to identify and seize the opportunities of a city to adapt to an increasing flood risk using OA.

Three chapters of this dissertation (namely CHAPTER 2, 3 and 4) encompass material of published articles by the author. Their content of these chapters largely overlap with the corresponding articles, but some sections have been modified for aligning it’s content with the other chapters.

1.2 Frequency and impacts of floods

Predicting future climate change is a challenge, as it is by its nature uncertain (Zandvoort et al., 2017). Implementing large scale measures and upgrading existing infrastructure to manage flood risk should be ideally a continuous process and be based on the latest insights with regards to potential future impacts caused by climate changes. The frequency and the overall impact (and changes therein) of flood events are the two driving factors for governments to take decisions regarding the potential investment in flood management measures. Flood risks can be divided into two main categories which set the boundaries of a continuum: low frequency/high impact and high frequency/low impact. Most of the time senior governments focus their attention on the first category, often resulting in responses involving large scale interventions (Botzen and Van Den Bergh, 2008). The 2nd category is more hidden, but in terms of accumulated yearly damage highly significant. The latter category calls for more localized, small scale interventions. Both require a dedicated approach, but synergies are there (Wynes and Nicholas, 2017) and a long-term strategy is needed in which the objectives of the two approaches are aligned (Zevenbergen, 2013).

In 2017, the Disaster Risk Financing and Insurance Program (DRFIP) and the World Bank (Confederation, 2016; Campillo et al., 2017) developed a risk-layering approach, which involves the development of a financing scheme focused on rapid response financing instruments, to protect against natural hazard events of different frequencies and severities. Fig 1-1 provides a graphic representation of the risk-layering approach, which is presented as a three-tiered sovereign risk-layering strategy for the national government of the G20 member countries (World Bank Group, 2017). Combining financing instruments also enables governments to take into account the evolving needs for funds dedicated to emergency response and to long-term reconstruction. For example, in the case of an event that represents a hazard of high frequency but low severity, there are no incentives for implementing new or upgrading existing large-scale measures. This is because the impact on the community and infrastructure of such a single event is low. But aggregating the impacts of all these (frequent) small events can be substantial and even outweigh those of low frequency/high impact events on a yearly basis (Jonkman et al., 2005). The largest part of the investment needs relates to low frequency and high severity events which have the biggest impact, like for example extreme events, as shown in Fig 1-1. Although these investments ultimately benefit more frequent low impact events, they are not necessarily focused on similar disaster risks. For instance, elevating river banks to limit riverine flooding of urban areas might impair outflow of urban drainage in those urban areas during moderate rainfall events and consequently increase local nuisance flooding. The question arises of how to efficiently plan and manage areas which are exposed to high frequency events with low impact? And which governance arrangements would fit best? The most important and biggest challenges in Flood Risk Management (FRM) are related to good planning as well as to good execution of the plan in question (implementation).

Fig 1-1. Three-tiers layering approach: Contingency budget is ideal for covering localized disasters which are a challenge for FRM

1.3 Urban adaptation

Today’s cities are increasingly affected by natural disasters, of which 85% are flood related (OFDA/CRED international Disaster Database, 2013). Of these, 65% are fluvial, 10% are due to tropical cyclones and 5% are pluvial flooding influenced by monsoons. Many of the associated flood impacts are expected to be exacerbated by climate change, which is often further boosted by land subsidence (Hallegatte et al., 2013). Zope et al. (2016) assessed the flood frequency change over time of megacities such as Mumbai and Bangkok, including fluvial flooding, pluvial flooding, and coastal flooding. There has been an increasing number of flood events affecting urban areas in the last decades. This increase is largely attributed to the topographical layout of cities and their growth (i.e. urban sprawl) (Veerbeek, 2017). Urban areas are vulnerable to flooding due to poor water management and urban planning and a lack of integration between the two. Based on empirical evidence, the impact of extreme climate events calls for adapting of infrastructure and spatial layout of built-up areas to reduce economic losses. This particularly holds true for developing countries due to the existence of an adaptation deficit (e.g., Fankhausera et al., 2013). Often referred to as ‘grey infrastructure’, traditional large-scale interventions result from a top-down decision-making process. These include amongst others improvements in flood defenses and urban drainage systems. These top-down approaches have proved to be effective in reducing flood risk and thus limiting damage from floods occurring in cities. However, measures pertaining to this category have long lead times and require large investments. Many cities around the globe have poorly maintained infrastructure and lack the capacity (incl. the financial resources) to upgrade or replace large scale flood management infrastructure systems. Bottom-up approaches involving small scale interventions (Mataki et al., 2007; Sayers et al., 2012; Metcalfe et al., 2017) may fill this gap and serve ‘to buy time’ as they have short lead times and require relatively low investments. Moreover, a blended top-down and bottom-up approach may also provide an appropriate answer to effectively deal with more frequent, low impact events. Such events are typically overlooked or lack the attention of national or local governments due to their creeping nature. Bangkok is one location where such an approach is likely required, as it is prone to flooding due to urban sprawl and low-lying flat areas (Hara et al., 2005; Sintusingha, 2006; Cao et al., 2019). In addition, the implementation of large-scale interventions, such as flood embankments and retention ponds as a response to the catastrophic 2011 flood, are still lagging behind (Vercruysse et al., 2019; Laeni et al., 2019). Public spaces and public utility buildings such as local markets, social housing, and parks have been built in flood-prone areas. The economic damage caused by flooding is expected to increase to about 100 million US dollars per year in Thailand (Terdpaopong et al., 2018). There is a growing awareness that both local scale as well as collective large-scale adaptation interventions are needed to manage the increasing flood risk in Bangkok. This notion extends to all cities that are dealing with pluvial, fluvial or other types of flooding.

Apart from climate change, there are other factors contributing to an increase of flood impacts. These are related to the location, composition and distribution of the built-up areas in urban agglomerations and thus to urban planning. Planning practices of urban developments and redevelopments often ignore flood hazards and therefore are responsible for a substantial increase in flood risk which is likely to exceed the expected impacts of climate change (Storch and Downes, 2011). Furthermore, governments tend to have a ‘silo orientation’ meaning they often consider existing problems from a single dimension leading to responses which are suboptimal. A typical domain where such a multiple perspective is needed is disaster management, requiring the involvement of multiple disciplines, governance levels and spatial scales (Radhakrishnan et al., 2017; Pathirana et al., 2017). Pluvial flooding is often perceived as a result of an insufficient discharge capacity provided by the drainage system, which leads to the single conclusion that its capacity should be increased (Yin and Li, 2001; Miller, 2015; Wei et al., 2019).

Localized flooding caused by poor public management and inadequate stormwater infrastructure has a significant negative impact on the local residents. It encourages autonomous adaptation initiated and implemented by individuals, communities and private enterprises affected by the flood (Forsyth and Evans, 2013; Mycoo, 2014). Unclarity about roles and responsibilities among public stakeholders lead to inaction to proactively manage floods and drives local actors such as the citizens and local communities to take action and put pressure on the local government (Shen, 2007; Montgomery, 2008; Huong and Pathirana, 2013; Francesch-Huidobro et al., 2017). Since flood protection measures have been implemented as a response to the 2011 flood in a haphazard way and at some locations even have not yet been fully installed, citizens and local businesses have taken action by themselves (Lebel et al., 2011; Marks, 2015; Singkran and Kandasamy, 2016). These individual actions, referred to as autonomous adaptation in this study include amongst others the installation of floodwalls around buildings. These interventions may adversely affect the effectiveness of the existing flood management system of the city government. For example, Limthognsakul (2017), revealed from her study in Bangkok that autonomous adaptation may spread flood risk to others, especially to vulnerable groups, and thus can be maladaptive.

A city is not static, but changes over time. These dynamics encompass a continuous process of development and redevelopment of buildings, infrastructure and other urban functions. These dynamics are creating ‘windows of opportunities’ for flood adaptation. In turn, if these opportunities are confined to a certain area and occur within a certain time period, together they represent the AP for that specific area and time period. Some scholars conceive urban flood adaptation as a continuous, bottom-up, socio-economic process rather than as a set of isolated, stand-alone adjustments (Gersonius, 2012). Hence, a more dynamic view on adaptation seems appropriate if climate change and socio-economic drivers are considered together. The combined approach has been referred to as ‘adaptation mainstreaming’ (Huq and Reid, 2004; Gersonius et al., 2012; Radhakrishnan et al., 2018). This includes climate change adaptation measures that are applied and integrated into autonomous urban development and redevelopment policies, plans and/or projects. The main intention is to adapt these policies, plans and projects in order to anticipate future changes. Adaptation mainstreaming requires an integrated approach and an understanding of the effectiveness of adaptation interventions such as the value added of adjusting (components of) the urban fabric to changing climatic and/or socio-economic conditions. There are many methods and frameworks available to develop and evaluate climate adaptation strategies and policies under uncertainty. Examples of such methods are: Adaptation Mainstreaming (Schipper et al., 2003), Real in Options (RIO) (e.g., Woodward et al., 2014), Adaptation Tipping Points (ATP) (Kwadijk et al., 2010), and Adaptation Pathways (Haasnoot et al., 2013). They all increase the flexibility of the resulting strategy by allowing to change over time in response to how the future unfolds. Computer simulation tools customized for designing and decision-making purposes are increasingly used to assess flood risk and how it evolves over time in urban areas. The flexibility of different risk management approaches is evaluated and compared using these simulation tools by identifying various responses to be implemented over time and their effectiveness by assigning a utility value to these responses (Fazey loan et al., 2016, Gersonius, 2012; Revi et al., 2014). The practice of adaptation mainstreaming is not new. For example, Schipper et al. (2003) provided historical evidence that the adjustment of standards for building codes a...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Summary
• Samenvatting
• Acknowledgements
• Table of content
• Figures and tables
• Acronyms and definition of terms
• CHAPTER 1 Introduction
• CHAPTER 2 Towards an Operational Method
• CHAPTER 3 Assessing the adaptation potential and opportunities of an urban area
• CHAPTER 4 Developing adaptation pathways Case study Kehanakorn
• CHAPTER 5 Decision tree method for evaluating the flexibility of flood risk adaptation options
• CHAPTER 6 Challenges to implementation of an Opportunistic Adaptation approach in Bangkok
• CHAPTER 7 Conclusions and recommendations
• References