Faith Ka Shun Chan

Flood Risk in Asia's Urban Mega-deltas Drivers, Impacts and Response

Asia’s urbanized mega-deltas are experiencing increased incidences of flooding. Flood risk is increasing due to urban growth, which makes people more vulnerable and threatens economic assets, and due to factors that increase flood hazard, including reduced delta aggradation, subsidence though natural resource extraction, and climate change, including extreme weather events, such as typhoons, and sea level rise. The recent history of flooding in Asia’s deltaic cities and the drivers of that risk have been examined in this article. We give particular attention to the Pearl River Delta, and its cities of Guangzhou, Hong Kong and Shenzhen, important economic centres of Asia. The flood risk is substantial, but flood risk management appear to suffer through a lack of sufficient strategic planning, and the difficulty of defending deltaic cities through traditional engineering approaches alone. Drawing on lessons from flood risk management internationally, we suggest that there are ways forward in developing flood mitigation strategies for deltaic cities in the region, which deserve further exploration.

Climate change, water management and stakeholder analysis in the Dongjiang River basin in South China

Abstract This article proposes a systematic analysis of water management and allocation on the scale of a river basin, considering climate impacts and stakeholder networks in the Dongjiang River basin in South China. Specific approaches are integrated to explore various subtopics. Findings indicate a slight increase of precipitation in the basin and strong fluctuations in this century due to climate extremes, which may lead to seasonal or quality-related water shortages. It is highlighted that alternative options for holistic water management are needed in the basin, and participatory water allocation mechanisms and establishment of a basin-wide management framework could be helpful.

Preparing for flooding in England and Wales: the role of risk perception and the social context in driving individual action

Flooding is a major threat to the local communities in the UK, and the risks are increasing due to climate change. Encouraging homeowners to prepare for the consequences of catastrophic flooding is imperative. This study aims to examine the ways in which individuals’ risk perceptions and socio-cultural characteristics co-determine the preparedness for flood hazards. It is based on a social survey about household arrangements that can reduce the economic losses arising from flooding and enhance community resilience. A total of 485 responses were solicited from homeowners in England and Wales. Results confirm that the intention to act is socially motivated. This indicates the need for addressing the role of social networks and engagement with local community in enhancing community resilience to flooding. On the other hand, the effect of risk-related considerations is complicated. Perceived severity of flood damage is associated with intended actions, whereas risk characteristics are not. This implies that although providing relevant risk information to the public is crucial, appealing to the feelings of fears and uncertainties is less likely to be effective in driving actions for managing flood risks than has been usually assumed. The findings have practical implications for policy-making and climate risk communication.

After Sandy: Rethinking Flood Risk Management in Asian Coastal Megacities

The tropical storm, and for a time hurricane, named Sandy arrived on the U.S. east coast on October 30, 2012, and delivered a 5.1-m storm surge, the highest since 1851, to the heart of the country’s financial hub in the Lower Manhattan area of New York City (NYC) (Fig. 1) [National Oceanic and Atmospheric Administration (NOAA) 2012]. As a result, there were more than 40 fatalities across the city, and the storm-related death toll across the northeast United States reached 63. Sixty-nine deaths in the Caribbean region meant that the total number of casualties caused by the storm was 132 [British Broadcasting Corporation (BBC) 2012; Fischetti 2012]. Public transport systems were submerged, the runways of two major airports (John F. Kennedy and Newark) were flooded and closed, and the New York Stock Exchange was shut down for 2 days. The forecasting firm Equcat estimated the likely total cost of damages to be more than

Research Articles: Coastal Flood-Risk Management Practice in Tai O, a Town in Hong Kong

85 billion (Reuters 2012b). Reuters estimated damage of at least

Developing a Sustainable Flood Risk Appraisal (SFRA) Framework for the Pearl River Delta

18 billion in the area between downtown and Long Island alone (Reuters 2012a). To put this in context, the average annual losses from cyclones, storm surges, coastal floods, and winds in the United States are estimated to be in the region of just

Biodiversity conservation should be a core value of China’s Belt and Road Initiative

10 billion per year. Although the magnitude of Sandy was less intense than Katrina in 2005, Sandy affected a larger area; the National Aeronautics and Space Administration (NASA 2012) reported strong winds (greater than 65 km=h) for a distance of approximately 500 km during Hurricane Katrina, whereas Sandy prevailed for over 1,500 km at a similar intensity. This is possibly the main reason why Sandy generated sea surges over a larger coastal area than did Katrina, and affected more than 12 states on the east coast [China Central Television (CCTV) 2012]. Previous research (Webster et al. 2005) has indicated that the frequency and intensity of cyclones (i.e., hurricanes and typhoons) has increased in the past 50 years, and that the trend is expected to rise continuously this century because of climate change. The Intergovernmental Panel on Climate Change (IPCC 2012) also reported that it is likely that there has been a poleward shift in the main Northern Hemisphere extratropical storm tracks, which means that the potential for intense storms that produce significant wind and extreme rainfall is slightly increased. The impact of Storm Sandy reflects the vulnerability of coastal megacities across the globe. This vulnerability exists because human settlement, including properties and infrastructure, is located mostly in low-lying flood-prone areas similar to those of New York City. The major financial hub of Wall Street, for example, is just a mile away from the harbor. An accepted definition of a megacity is a city with a population of 8 million or more (United Nations 2010). NYC has 8.2 million inhabitants, approximately 2 million of whom live on Long Island or smaller islands and in flood-prone areas. The city government realized that it would be impossible to relocate this number of people and associated assets outside of the hazard areas, and has therefore started to adapt flood-management strategies in preparation for climate change (NYC Government 2012). Adaptation practices such as assessment of surge risk, flood-risk mapping, prediction of risks from various climate scenarios, and enhanced emergency evacuation plans have been implemented since 2010 (Klima et al. 2011). The city’s storm warning system was activated some 41 h before Storm Sandy arrived, at which point city authorities announced the closure of the financial markets and advised residents to stock up on food and water. Recommendations to employ sandbags for flood

Household economic resilience to catastrophic rainstorms and flooding in a chinese megacity

Coastal megadeltas in Asia have emerged rapidly; their megacities are particularly stressed by urbanization and rapid population growth. In the Pearl River Delta, towns in coastal megacities, such as Hong Kong, experience severe land shortage, which has led to the installation of essential infrastructure in flood-prone areas. Floods from the storm surge of two recent storms, Typhoons Hagupit and Koppu in 2008 and 2009, respectively, damaged over 100 properties in the Tai O, Hong Kong. Although projected sea-level rise and frequent storms pose a serious threat for the foreseeable future, flood management is inadequately understood by the various stakeholders in Tai O. Based on interviews of 22 stakeholders related to flood-risk management in Tai O, this article highlights the similarities and differences in the prevailing perceptions of coastal flood management practices. In addition, the report highlights the need for urgent attention so as to establish an integrated coastal flood-risk management strategy that will involve all stakeholders in mitigating the emerging flood vulnerability of the coastal communities.

Governance challenges of flood-prone delta cities: Integrating flood risk management and climate change in spatial planning

Intensive storms enhanced flooding is fast emerging as one of the biggest threats to urbanization in Asia. The need to manage this risk is critical for achieving a sustainable growth pattern. The authors study the Pearl River Delta (PRD) and propose a generic sustainable flood risk appraisal (SFRA) framework that can be used to benchmark flood risk management (FRM) practice against sustainability objectives. The framework addresses social, environmental and economic concerns, and further illustrates that climate change and governance are two main drivers to achieving sustainability in FRM. This article further explains how the template could be of value in recuperating the FRM practices in the PRD.

Sustainable drainage systems: Helping people live with water

To the Editor — China’s Belt and Road Initiative (BRI; also known as ‘One Belt One Road’) is potentially the largest infrastructure development in our lifetime. In 2013, President Xi Jinping revealed his vision for BRI, which is expected to be core to China’s development strategy for at least the next decade1. With an estimated cost of over 4 trillion US dollars, BRI will connect roughly half of the world’s population, across more than 65 countries, with land and marine routes2,3. Although much has been discussed about its economic and geopolitical implications, the implications of BRI for biodiversity must also be considered, especially in Asia. Infrastructure and its impacts are key drivers of biodiversity loss. BRI will cross several terrestrial and marine biodiversity hotspots4,5, wilderness areas6 and other key conservation areas, such as southeast Asia’s Coral Triangle6 (Fig. 1). These disruptions will create obvious threats to biodiversity. Roads, for example, open a Pandora’s box of environmental impacts, such as habitat loss, fragmentation, invasive species, and illegal activities such as poaching and logging7. In the marine environment, increased sea traffic exacerbates the movement of invasive species and pollution8,9. Poorly planned infrastructure has the risk of locking in undesirable environmental practices for decades to come. BRI could have disastrous consequences for biodiversity. We challenge decision-makers, infrastructure planners and conservationists to work together not only to mitigate BRI’s negative impacts, but also to think how to transform this juggernaut into an opportunity for biodiversity. If BRI adopts biodiversity conservation as one of its core values, it could, for example, plan and implement a network of protected areas and wildlife corridors across Eurasia. In much of BRI’s region, especially in southeast, central and western Asia, there is a clear