1. Introduction and

Outlines of the Knowledge

Notes

Simple assessments of Coastal Problems, Adaptation and Disaster Risk Management Solutions.

Simple assessments of Coastal Problems, Adaptation and Disaster Risk Management Solutions.

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Introduction and Outlines of

the Knowledge Notes

Authors

Alessio Giardino, Leo Van Rijn, Ellen Quataert, Leo Van Rijn,

Andrew Warren, Ad Jeuken, Hans de Vroeg, Nicolas Desramaut,

Sofia Bettencourt

Simple assessments of Coastal Problems, Adaptation and Disaster Risk Management Solutions.

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Simple assessments of Coastal Problems, Adaptation and Disaster Risk Management Solutions.

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Introduction and Outlines of 1.

the Knowledge Notes

Deltares – GFDRR

1.1 Introduction 1.2 Objectives 1.3 Background and basic definitions 1.4 References

1.1. Introduction

Small Island States around the globe are very susceptible to natural disasters. Storm surges, coastal

erosion, cyclones, tsunamis, flash floods from rivers, can have devastating consequences at those

countries. Moreover, these effects are exacerbated by global climate change, climate variability and sea

level rise. As their population, agricultural land and infrastructure tend to be concentrated in the coastal

zone, any rise in sea level will have significant and profound effects on their economies and living

conditions; the very survival of certain low-lying countries will be threatened. Shared structural

disadvantages and characteristics place them at an economic disadvantage and prevent economies of

scale, hindering sustainable development and making them less able to recover after a disaster than larger

and more diversified economies. Consequently, small island states are particularly vulnerable to the

pervasive impact of natural disasters on their populations, environments and economies.

Figure 1.1 Aerial view of one of Kiribati islands

Generally, small island states in developing countries lack the data and technical capacity in hydraulic and

coastal engineering as well as the socio-economic skills to properly assess the most cost-effective

interventions appropriate to each vulnerable coastal area, particularly when the affected areas are

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relatively small, poor and very vulnerable. These knowledge notes, with the accompanying freely available

tools, aim at closing this existing gap.

The project has been developed in close cooperation with other on-going activities at The World Bank (i.e.

in West Africa and in São Tomé) and the Small Island States Resilience Initiative (SISRI) for which

coastal protection is a an emerging business line.

1.2. Objectives

The aim of this project is to assist practitioners to carry out simple, preliminary assessments of problems

and solutions with the use of simple knowledge notes and freely available tools downloadable from the

website (http://www.simplecoast.com/toolstutorials) and combined with targeted capacity building

actions (http://www.simplecoast.com/events-trainings-2/). The knowledge notes and tools will be

available for further use anytime in the future, also within other projects.

This activity targets practitioners from developing countries who may lack the data and expertise for more

complex assessments, in particular practitioners from local and national governments, local universities

or national consultants who do not have the means or skills to purchase and use complex modeling

packages. Good coastal and hydraulic engineering and socioeconomic skills are essential for proper

assessment of cost-effective interventions to increase the climate resilience of these vulnerable countries.

The layout of these knowledge notes is explained below.

Chapter 2 (Adaptive Approaches to Coastal Zone Management) provides an overview of general

approaches, options and practices to Integrated Coastal Zone Management. This includes the formulation

of general objectives and a framework of analysis for a ICZM plan, the definition of indicators to evaluate

the effectiveness of the plan and the implemented adaptation options.

Chapter 3 (Coastal Processes and Problems) focuses on a description of the main physical

processes, important for the understanding of the physical systems in coastal areas, and with a particular

emphasis to the settings of small island states. A collection of basic formulas and graphs widely used in

coastal engineering is also provided. Those formulas, among others, are also implemented in the freely

available tool-kit provided alongside the knowledge notes.

Chapter 4 (Data Collection and Monitoring) provides basic information for simple methods of data

collection and monitoring, crucial for the understanding of the coastal systems and to evaluate possible

changes to coastal indicators. Coastal indicators are very useful to evaluate the efficiency of different

adaptation options.

In Chapter 5 (Coastal Adaptation Solutions), a number of different adaptation technologies are

described and grouped under the following main approaches: soft protection, hard protection,

accommodation and retreat. For each of the approaches, basic technologies, advantages and drawbacks

are described alongside a rough costing. Simple tools for a preliminary design of these options is also

presented as part of the simple tools.

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1.3. Background and basic definitions

In this section, a number of concepts are defined which will be used alongside the different chapters.

Integrated Coastal Zone Management (ICZM) is the basic framework used for planning purposes

in the coastal areas. The framework supports the integration of the bio-physical, socio-economical and the

institutional system (see knowledge note “Adaptive Approaches to Coastal Zone Management”). Data and

tools are the basic of these three pillars, helping identifying the problems and designing and monitoring

the efficiency of the different solutions.

A very important concept when considering different adaptation options for coastal problems is the

concept of risk. This study adopts the definition of risk suggested by Kron (2005). According to this

definition, risk is a product of three factors (Figure 1.2): hazard, exposure and vulnerability.

Hazard is the probability and magnitude of an event with negative impacts. For example, in flood risk,

hazard is usually given in a set flood hazard quantity (e.g. inundation depths) per return period. The

knowledge note on “Coastal Processes and Problems” deals specifically with hazards.

While hazard is related to the physical system aspects of risk, i.e. natural events with negative impacts,

exposure and vulnerability encompass socio-economic characteristics (Figure 1.2). More specifically,

exposure relates to exposed assets and people and, in the case of assets, refers to the total value of

properties found in the inundated area (Kron, 2005).

In practice, exposure can be assessed with spatial information, by looking for instance at land use and

land cover maps, in combination with the afore-mentioned flood depth maps (Figure 1.3). The last factor,

vulnerability, refers to the damage inflicted upon exposed property in case of flooding (Hinkel, 2011;

Kron, 2005). When combined with a hazard quantity such as water depth, vulnerability can be modeled

with the use of damage curves, which depict the percentage of maximum economic damage per asset and

per hazard quantity for each asset type (Holz et al., 2015; Rojas et al., 2013; Deltares, 2016).

Based on the aforementioned information, a quantification of hazard, exposure and vulnerability for the

case of flooding, results in risk being in monetary values per return period (see Error! Reference

source not found..1). This concept is very important in order to compare the cost-effectiveness of

different proposed solutions (Deltares, 2016).

Table 1.1 Quantities and units in the definition of risk (Bouziotas, 2016).

Factor Quantities Units

Hazard Water Depth per Return Period

⁄

Exposure Number of assets

Vulnerability

Damage per Water depth per asset

Risk

Damage per Return Period ⁄

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Figure 1.2 Definitions of risk from literature. Upper panel: Risk definition from IPCC (2014), bottom left panel: definition used by OECD (2013), bottom right: definition in this study, adapted from Kron (2005).

Figure 1.3 Flood risk as the interaction of hazard (probability of occurrence and magnitude-intensity), exposure and vulnerability (Adapted from Merz, Thieken, and Kreibich 2011).

Given a certain hazard, in general, three different options exist to adapt to coastal hazards as first

suggested by IPCC CZMS (1990):

- Protect: defend vulnerable areas, especially population centers, economic activities and natural

resources

- Accommodate: continue to occupy vulnerable areas, but accept the greater degree of the coastal

hazard (e.g. flooding, coastal erosion), by changing land use, construction methods and/or

improving preparedness

- (Planned) retreat: abandon structures in currently developed areas, resettle inhabitants and

require that new developments be set back from the shore, as appropriate.

EXPOSURE AND VULNERABILITY

vulnerability

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Figure 1.4 Different coastal adaptation strategies: protect, accommodate and retreat (based on IPCC CZMS (1990).

Protection approaches in turn can be distinguished between soft and hard approaches (see knowledge

note on “Coastal Adaptation Solutions”). A soft solution uses natural processes and materials for

protection (e.g. sand and gravel nourishments, coastal restoration using vegetation, coral reef restoration,

etc.). A hard defence represents the traditional approach to coastal defence, by using structural

measures as coastal defence (e.g. groynes, detached breakwaters, seawall, seadikes, revetments, etc.).

In order to assess the efficiency in time of a certain coastal protection measure, suitable coastal

indicators have to be defined and then monitored regularly in time (see knowledge note on “Data

Collection and monitoring). The definition and monitoring of coastal indicators is a crucial step during

the implementation of an ICZM plan.

1.4. References

Bouziotas, S.B., 2016. Upscaling coastal flood risk assessment. Insight into the uncertainty of a

continental-scale model. Master thesis, TUDelft. Delft, The Netherlands.

Deltares, 2016. Coastal Risk Assessment for Ebeye. Technical report. Project num. 1230829-001. Delft,

The Netherlands.

Hinkel, J. (2011). “Indicators of vulnerability and adaptive capacity”: Towards a clarification of the

science–policy interface. Global Environmental Change, 21(1), 198–208.

Holz, F., Burzel, A., Winsemius, H., & Bouwer, L. (2015). A European-scale approach to flood risk

assessment: a land use based appraisal of present and future flood risk as support for climate change

adaptation and disaster risk reduction using FIAT.

IPCC CZMS (1990). Strategies for Adaptation to Sea Level Rise. Report of the Coastal Zone Management

Subgroup, Response Strategies Working Group of the Intergovernmental Panel of Climate Change. The

Hague: Ministry of Transport, Public Works and Water Management.

IPCC (2014). Fifth Assessment Report of the Intergovernmental Panel on Climate Change (AR5).

Retrieved from http://www.ipcc.ch/report/ar5/

Kron, W. (2005). Flood Risk = Hazard • Values • Vulnerability. Water International, 30(1), 58–68.

http://doi.org/10.1080/02508060508691837

Protect Accommodate Retreat

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Merz, B., Thieken, A., & Kreibich, H. (2011). Quantification of socio-economic flood risks. In Flood Risk

Assessment and Management (pp. 229–247). Springer.

OECD. (2013). Water security for better lives.

Rojas, R., Feyen, L., Bianchi, A., & Dosio, A. (2012). Assessment of future flood hazard in Europe using a

large ensemble of bias-corrected regional climate simulations. Journal of Geophysical Research:

Atmospheres, 117(D17), n/a–n/a. http://doi.org/10.1029/2012JD017461