Living with coastal erosion in Europe:Sediment and Space for Sustainability

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Service contract B4-3301/2001/329175/MAR/B3 “Coastal erosion – Evaluation of the need for action” Directorate General Environment European Commission

Living with coastal erosion in Europe:

Sediment and Space for Sustainability

Guidelines for implementing local information systems

dedicated to coastal erosion management

Executive Summary

17 May 2004

National Institute for Coastal and Marine Management of the Netherlands (RIKZ) EUCC – The Coastal Union IGN France International Autonomous University of Barcelona (UAB) French Geological Survey (BRGM) French Institute of Environment (IFEN)

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Guidelines for implementing local information system Executive summary

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This document briefly summarizes the main outcome of EUROSION Work Package 3, which aimed at developing guidelines local information systems dedicated to coastal erosion management. These guidelines are intended to help regional authorities willing to make a major contribution to coastal erosion management and coastal information sharing. A complete set of EUROSION Guidelines for implementing local information systems can be obtained upon request.

WHAT IS A LOCAL INFORMATION SYSTEM ?

An information system (IS) can be defined as “a set of technological, human, organisational, financial, and information resources organized in such a way to produce, archive, retrieve, modify, process, combine, represent, exchange and/or disseminate information with a view to reach the objectives the system is designed for”.

By local information system, and with reference to the above-mentioned definition, we mean that the objectives for which the system has been designed for, relate to a restricted geographical area, ranging from a municipality to a regional entity.

Although a number of other IS definitions tend to put the technology upfront (computer-based), it is worth mentioning that institutional, organisational and political aspects account for the greater share in the success (or failure) of an information system.

WHICH ASPECTS MUST BE TAKEN INTO CONSIDERATION?

Designing, developing, installing and maintaining a local information system (LIS) dedicated to coastal erosion management require taking a wide range of aspects into consideration simultaneously. These aspects may be grouped in six categories as shown in the figure below:

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More precisely:

Functional specifications. Functional specifications aims at clarifying the objectives of the

information system. They describe which coastline management decisions are to be supported by the system, as well as their data requirements. To some extent, the functional specifications are the raison

d’être of the information system.

Organisational and institutional procedures. The design, development, installation and

maintenance of any information system require well-tried organisational procedures which aim at ensuring that the system will meet the expectations of the different stakeholders and is implemented within an agreed time schedule and budget constraints.

Data content specifications. Data constitute the fuel of the information system. This section

thoroughly describes the typology and nature of data which have been identified by the technical specifications. Besides, this section also provides information on the methods and costs associated to data production.

Data storage and access technologies. This part describes the mechanisms through which

information is physically archived and made available to a wide public. It notably describes the standards to be used for exchanging data from one computer to another and for documenting the content, quality and access conditions of the data themselves.

Data modelling. Data modelling is about the architecture and the structure of the data, concentrating

on the logical entities and the logical dependencies between these entities. Data modelling is a critical aspect of information system development since the ability of the system to combine and cross-analyse data will depend on it.

Data spatial representation. Data spatial representation deals with the location of physical objects or

phenomena described by the data collected and how this location will be characterized. A common way of describing location is to use geographic or cartographic coordinates which refers to a specific geographic reference system and a specific cartographic system. Failure to adopt a standard geographic reference system or a specific cartographic system may result in the impossibility to cross-combine information and represent them consistently on one map.

A. FUNCTIONAL SPECIFICATIONS

The objectives assigned to local information systems may vary considerably from one site to another. In the fields of coastline management however, experience gained from EUROSION pilot sites makes it possible to define these objectives as answers to frequently asked management questions. To a large extent, these management questions are linked to investment decisions, which can be summarized as follows :

• Will my investment be exposed to coastal erosion hazard during its lifetime ?

• Will my investment impact coastal erosion processes ?

• Do the benefits generated by my investment (including the environmental benefits) exceed its costs (including environmental costs) ?

The answers to these questions are far from obvious and generally require a considerable amount of data from different nature and different sources. In line with these three questions, EUROSION proposes the development of local information systems dedicated to three main functionalities.

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Function 1 - Hazard assessment

Coastal erosion hazard assessment has been identified during the EUROSION study as the first function which would justify investing in a local information system. Depending on the type of coasts, erosion hazard may be relating to the loss of lands, and together with them, the economical assets they support (e.g. cliff retreat or beach lowering), or it may be relating to the flooding of coastal plains either as a direct result of acute dune erosion or as a result of sea defence undermining by chronic coastal erosion. In both cases however, the data requirements identified during EUROSION investigations are the same and can be listed as follows:

• Aerial orthophotographs (alternatively satellite images)

• Current and historic coastline

• Terrestrial elevation

• Near-shore bathymetry (alternatively offshore bathymetry)

• Cross-shore profiles

• Coastline geomorphology

• Coastline geology

• Seafloor sedimentology

• Sediment transport

• Near-shore wave regime

• Offshore wave and wind regime

• Near-shore currents

• Astronomic tide

• Still water level

• Coastal defence works

The following figures provide some examples of the use of information systems to generate maps of coastal erosion hazard.

Illustration of an inundation process using a flood simulation model (MIKE Flood) integrated to a coastal information system. Source: Danish Hydraulics Institute (DHI)

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1. This photograph depict a segment of the coast of Haute-Normandy (Criel-sur-Mer) which is characterized by highly erodible chalk cliffs. Two coastline positions, respectively from 1966 and 1999, were extracted from orthophotographs. The coastline was then divided into equidistant segments for which the loss of land between 1966 and 1995 was estimated. Here, an equidistance of 100 metres was selected.

2. The loss of lands between 1966 and 1995 is converted into an annual erosion rate for each 100 metre long segment. Annual erosion rates for the entire coastline is reflected into a histogramme as depicted beside.

3. In turn, the erosion rate is used to estimate the future shoreline position by simply multiplying the erosion rate by the number of years considered (e.g. 50 or 100 years in the future)

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Function 2 – Impact assessment

Human activities may impact coastal erosion processes in a variety of ways. In all cases, changes take place whenever one or more of the above mentioned natural causes of coastal erosion are modified. EUROSION proposes to consider the following typology of impacts on coastal erosion processes and impacting projects:

• Impact 1: modification of near-shore bathymetry and wave propagation patterns • Impact 2: disruption of long-shore drift currents

• Impact 3: removal of sediment from the sediment system • Impact 4: reduction of river debits

• Impact 5: reduction of volume of tidal basins • Impact 6: modification of near-shore vegetation • Impact 7: modification of soil weathering properties • Impact 8: modification of Aeolian transport patterns • Impact 9: land subsidence

A wide range of projects is concerned with such modifications. They can be grouped in 6 categories:

• Category 1: Land reclamation projects • Category 2: River water regulation works • Category 3: Sediment extraction projects

• Category 4: Construction of tourism and leisure facilities • Category 5: Coastal defence works

• Category 6: Hydrocarbon and gas mining activities

Table below provides an overview of how above mentioned projects impact coastal erosion processes.

In order to assess the impact of human activities on coastal erosion processes, EUROSION proposes that the following data requirements are taken into consideration in the perspective of local information systems:

• Aerial orthophotographs (alternatively satellite images)

• Current and historic coastline

• Infrastructure

• Hydrography

• Terrestrial elevation

• Near-shore bathymetry (alternatively offshore bathymetry)

• Cross-shore profiles

• Coastline geomorphology

• Coastline geology

• Seafloor sedimentology

• Sediment transport

• Near-shore wave regime

• Offshore wave and wind regime

• Near-shore currents

• Astronomic tide

• Still water level

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Typology of projects having an impact on coastal erosion processes IMPACTS PROJECTS Modification of bathymetry and/or wave propagation patterns Disruption of long-shore currents Removal of sediment from the sediment system Reduction of river debits Reduction of volume of tidal basins Modification of near-shore vegetation Modification of soil weathering properties Modification of Aeolian transport patterns Land subsidence Land reclamation • Harbour/airport extension _ü _ü _ü

• Energy production plants (e.g.

windfarms) ü ü ü

• Recreational parks _ü _ü _ü

River regulation works

• River damming _ü _ü

• Irrigation systems _ü

Sediment dredging

• Channel dredging for navigation _ü _ü _ü

• Aggregate extraction for

construction ü ü ü

• Sand extraction for nourishment _ü _ü _ü

Construction of tourism/leisure facilities

• Marinas _ü _ü

• Hotel resorts _ü

• Recreational parks including golf

amenities ü ü

Coastal defence

• Cross-shore hard defence including groins, breakwaters and jetties

ü ü ü

• Alongshore hard defence including seawalls, bulkheads and revetments

ü ü

• Beach nourishment (see

sediment extraction) ü ü ü

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Guidelines for implementing local information systems Executive summary

Function 3 – Cost Benefit analysis

In a significant number of cases, investments relating to shoreline management and/or coastal defence are decided though a poor attention has been paid to social, environmental and economical studies. This has lead to situations where the costs of shoreline management exceed its long-term benefits. To avoid these situations, EUROSION has reviewed a number of considerations which could lay the foundations for further works and research to be undertaken in connection with cost-benefit analysis of shoreline management investments and the development of local information systems. These considerations put the emphasis on the role of the following data requirements :

• Infrastructure

• Land cover

• Land cover changes

• Demography

• Areas of high ecological value

• cultural heritage

• Land market value

• Economic registered activities

• fishery and aquaculture concession

• mineral extraction concessions

Next page presents an example of cost-benefit analysis applied to shoreline management and which could benefit from local information systems dedicated to coastline management.

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Example Cost-Benefit Analysis: Hondsbossche Sea Dike in the Netherlands

Current Situation (i)

Hold the line (A)

Move Seaward (B)

Move landward (C)

Drive: sandy variations (multifunctional)

The old Hondsbossche Sea Dike or “Hondsbossche zeewering” (1880, length: 5 km) shows currently several problems amongst which sea level rise, increasing erosion, instability and inflexibility (compared to a sandy coastline retreat) and consequently it sticks out by approximately 200m.

3 types of possible solutions are proposed, summarised by hold the line (A), move seaward (B) and move landward (C). Before deciding on measures a balanced cost-benefit analysis has to be made where all interests have to be incorporated. In (A) the current policy will be continued (maintenance with nourishments), in (B) the dike will be dismantled and a dune area will be raised. This alternative is primarily focused at recreational purposes. In (C), the dike will be dismantled without replacing it, an alternative for more ecological value. This example focuses more on the benefits of the different options and gives some illustrative approaches. The

costs can be assessed in the more traditional way:

Costs \ Option Hold the line (A) Seaward (B) Landward (C)

Investment (M €) 137,5 227,4 4,5

Maintenance (M € / 30yr) 20,7 4,0 144,5

The process of qualifying and quantifying the benefits of these separate options was done following a certain method where the distinction was made between three different aspects: (1) Money (economical); (2) Green (Ecological); and (3) Feeling (socio-cultural), after which an integrated approach was made to prioritise the different judgement criteria.

Part of: Benefit Assessment “Money” :

Type of benefit Effect Assessment method

Returns agriculture Push out production _{Change productivity} Market values

Safety perception Change perception Contingent Valuation Method Recreation Change number of tourists

Change perception Travel cost approach Fresh water storage /

extraction Production Market prices

Fishery benefits Creation breeding ground Production function method Economical activity Mitigated flood damage Risk assessment Property value Change house prices

Change number of houses

Hedonic prices Market value

Part of: Benefit Assessment “Green”:

Ecological benefits are quantified and assessed according to the envisaged changing aspects of ecological diversity. The table below shows a relative scoring which may give an indication of different political visions on nature.

Score \ Option Hold the line (A) Seaward (B) Landward (C)

Ecosystem diversity 0,12 0,31 0,46

Species diversity 0,21 0,21 0,22

Natural quality 0,16 0,50 0,73

Part of: Benefit Assessment “Feeling”:

The researcher involved in the ex ante assessment of socio / cultural benefits of certain management options may follow the following steps: (1) Reviewing of existing literature regarding comparable cases; (2) Examination of existing maps on the different reference topics and gathers information on notes, municipal guides and internet sites; (3) Makes an inventory of different stakeholders and their interests; (4) Consults one or more boards of stakeholders for advise on the necessary steps towards decision, supported by expert opinions; and (5) Bundles the obtained information and requests additional research on sensitive topics.

Focus on the latter two:

A simple method to quantify feeling is to let the stakeholders give a score of 100 to their main project goal, and percentages of 100 to other project goals, this to make the differences between stakeholders transparent: In the table below for 2 groups (G1 and G2):

Project goals Most preferable outcome Least preferable outcome Rough weights G1 G2 Preserving safety culture Responsibility government Appear to be left to nature 100 100 Increase tourism Unique

identity No distinction with others 60 60 Increase amenity Keeping polders Removing polders 60 30 “Authentic” nature Recovery sea inlet No sea inlet 0 60 Limiting lasting congestion No intensive constructions Intensive constructions 20 20 Keeping flexibility Lasting options No options ₂₀ ₂₀

The next step is to score the project goals relative to the 3 different management options by the groups, e.g. from 0 to 1. Multiplying the two scorings a weighed total score can be achieved.

The final step involves an integrated assessment of the three aspects on the three management options to get a complete overview of the project. This is essential for both the presentation and communication towards stakeholders and local citizens. Also, this overview is needed to give the decision – and policy makers some grip to balance the respective management options between the aspects of Money, Green and Feeling (Source: Baten van Water, zoute case studies, 2002 – in Dutch).

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B. ORGANISATIONAL AND INSTITUTIONAL PROCEDURES

Political, institutional and organisational arrangements appear to be among the most critical factors when designing and implementing an information system. These arrangements express the willingness of a group of stakeholders to put their information resources on a common platform, and therefore guaranty its sustainability. In a sense, these arrangements define a “coastal information governance strategy” which will set the institutional basis for the design, implementation and operational functioning of local information systems. This governance strategy needs to be formally endorsed by all involved stakeholders in order to ensure commitment and responsibility division.

EUROSION proposes to build such coastal governance strategies upon 9 principles which are:

• Principle 1 - a lead authority working in partnership with a wide range of local to national

stakeholders;

• Principle 2 – a commitment to share relevant information (or data);

• Principle 3 - use a well-documented web-based information system using internationally

recognised standards;

• Principle 4 - institutions retain responsibility for their own data including quality, timeliness

and for its dissemination;

• Principle 5 - the information system should be based on relevant and reliable data; • Principle 6 - adequate training;

• Principle 7 - cost sharing by all partners; • Principle 8 - the system is reviewed periodically;

• Principle 9 – regular review of the strategy realisation and performance

Moreover, there is a need to adopt a project-wise approach to make sure that the information system is implemented according to pre-established terms of reference and that its implementation receives appropriate guidance from the partner institutions.

This has lead the EUROSION project to propose a manual of procedures, to be formally amended and approved by all stakeholders, providing clear insight in the different phases of development, expected input and responsibility of each involved stakeholder, their interdependence and the obtained end result of the specific phase. The phases, responsibilities and results may vary along the process due to unforeseen changes, political choices or newly obtained knowledge, so flexibility is an essential element.

OUTLINES FOR A “LIS” MANUAL OF PROCEDURES I.1. Feasibility and pre-design study

I.1.1. Designation/recruitment of a LIS project manager I.1.2. User need requirement survey

I.1.3. Inventory of existing sources of information available at the local level I.1.4. Elaboration of specific technical specifications for the LIS

I.1.5. Assessment of implementation costs I.2. Implementation

I.2.1. Kick-off meeting with all stakeholders

I.2.2. Adaptation of EUROSION prototype to match the requirements of the feasibility and I.2.3. Implementation and test phase

I.2.4. Training I.2.5. Marketing I.3. Management and maintenance

I.3.1. Submission and resignation procedures I.3.2. Arbitration procedures in case of a conflict I.3.3. Annual budget planning procedures I.3.4. Access rights management procedures I.3.5. Forum management procedures I.3.6. Data quality control procedures I.3.7. Training procedures

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C. DATA CONTENT SPECIFICATIONS

The scope of this section is to review which datasets will contribute to answer critical questions for coastline management. These critical management questions have already been discussed earlier in this document.

On the basis of the review of past and ongoing experiences in coastline management conducted Europe-wide in the framework of EUROSION, 31 relevant datasets or “reference topics” that we have organised in 9 topic groups have been identified. These reference topic groups and topics include:

Reference topic group 1 – Administrative boundaries

• Reference topic 1.1 - terrestrial boundaries

• Reference topic 1.2 - maritime boundaries Reference topic group 2 - Topography

• Reference topic 2.1 – Aerial photographs / orthophotographs

• Reference topic 2.2 –Satellite images

• Reference topic 2.3 - Current and historic coastline

• Reference topic 2.4 - Infrastructure

• Reference topic 2.5 - Hydrography

• Reference topic 2.6 - Terrestrial elevation

• Reference topic 2.7 - Near-shore bathymetry

• Reference topic 2.8 - Offshore bathymetry

• Reference topic 2.9 - Cross-shore profiles

Reference topic group 3 –Geomorphology, geology and sedimentology

• Reference topic 3.1 - Coastline geomorphology

• Reference topic 3.2 - Coastline geology

• Reference topic 3.3 - Seafloor sedimentology

• Reference topic 3.4 - Sediment transport

• Reference topic 3.5 - Sediment-dwelling (benthic) infauna Reference topic group 4 - Hydrodynamics

• Reference topic 4.1 - Near-shore wave regime

• Reference topic 4.2 - Offshore wave and wind regime

• Reference topic 4.3 - Near-shore currents

• Reference topic 4.4 - Astronomic tide

• Reference topic 4.5 - Still water level Reference topic group 5 - Land cover

• Reference topic 5.1 - Land cover

• Reference topic 5.2 - Land cover changes Reference topic group 6 – Demography

• Reference topic 6.1 - Demography Reference topic group 7 - Heritage

• Reference topic 7.1 - Areas of high ecological value

• Reference topic 7.2 - cultural heritage Reference topic group 8 – Economic assets

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• Reference topic 8.1 - Land market value

• Reference topic 8.2 - Economic registered activities

• Reference topic 8.3 - fishery and aquaculture concession

• Reference topic 8.3 - mineral extraction concessions Reference topic group 9 – Coastal defence

• Reference topic 9.1 - coastal defence works

D. DATA STORAGE AND ACCESS TECHNOLOGIES

The purpose of this section is to describe the common requirements related to the technology used to make the data and information accessible. Besides requirements of the data and information (format, metadata, coordinates etc.) the technical specifications used allow broad access, requiring soft and hardware standards. These requirements are intended for system architects, database designers, and software developers who will implement these requirements in different LIS applications, and can be summarised as follows:

• Storage. The data present need to be stored into a physical place, supported by a hardware

platform and into a professional (relational) database in order to provide a consistent structured methodology for standard compliance and long term knowledge embedding. The storage of data is in principle best guaranteed at the location to which the main usage is to this data given, ensuring continuation and long-term homogenous information. Server capacity, backups and the stability need specific definition for both storage and access.

• Access. Wide access to data (and information) to stakeholders (involved in risk mapping) can

be facilitated through Internet technology; access requires limited effort, can be monitored and restricted if required. Distributed technologies allowing access to local internet sites ensure provision of timely information leaving the storage at the place of origin. Means to define the exact information required can be done through querying the database. Existing technologies to facilitate the web-access are FTP-sites, websites allowing querying at the proper site, portals connecting multiple distributed databases and information systems (CoastBase, others…) and common used Internet search engines (google, yahoo etc.). The services to be provided need to encompass effective searching, viewing downloading, data transformation, and presence of metadata.

• Security. Firewalls, specific user identification and passwords can improve the proper use of

the information

• Maintenance. System maintenance at the information holder site includes regular hardware

and software investments. Licences for all kind of applications.

• Interface. Common interfaces used for data access, allowing google-like free text search as

well as advanced access through search form, glossaries and maps. The use of multilingual thesaurus has been identified as a strong requirements by non-English users.

In the course of EUROSION a prototype of data storage and access technologies implementing the above-mentioned requirements has been developed and can be obtained upon request. This prototype has been built upon the CoastBase technologies. The following pictures present screenshots of this prototype.

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1. The home page of LIS can be customized for each region willing to implement its own LIS. In this example, the home page has been customized to fulfil the expectation of the Isle of Wight County. Visitors can only access a few functionalities (e.g. search). Only authorised user may access the full range of functionalities through a login name and a password.

2. Authorised users can (in particular) upload new datasets in the system. Uploading new datasets requires filling in a complete metadata formulaire compliant with ISO 19115. Each user is responsible for the quality and the maintenance of data he/she uploads.

3. Both geo-coding of uploaded datasets and research of information is performed using a mapserver. This tool makes it possible to navigate on a map (with the possibility to zoom in and zoom out) and to capture the rectangular coordinates (latitude, longitude) of the dataset bounding box. A bounding box defines the geographical extent of a particular dataset (here approximately the county Mayo).

4. Beside research by geographic location, search may also be performed on the basis of free text or a thesaurus. A thesaurus facilitates storage and retrieval of datasets by describing the datasets with a standardized set of keywords. Research can also be performed by date.

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Up-scaling and down-scaling possibilities

Besides the importance of proper access to information another relevant component is the possibility to aggregate information from local level to European scale and reverse. Three main reasons for this were identified, firstly validation and representation purposes of European scale geographical information ‘at the ground’. Secondly the potential European semantic network at the local, benefiting from the INSPIRE initiative and principles supports the growing of an operational Europe covering distributed network. This network aims at feeding the information updating and feedback processes. Thirdly co-operation and commitment between authorities actuating at different levels is enhanced when concretising the information sharing and fluxes through such network. A summary is given and an attempt to come to determination of the benefits of such network.

Standardisation of key datasets required for delimiting coastal sediment cells

In line with the recommendations on assessment of hazards, environmental impacts and cost benefit analysis coastal sediment cells are deemed to constitute the units for managing coastal erosion. However, experience in Europe has shown that the delineation of coastal sediment cells is a far from trivial task and suffers from a lack of consistency Europe-wide. Efforts should be undertaken to increase the consistency of coastal sediment cell delineation throughout Europe notably by standardizing the production of key input datasets for such delineation.

The INSPIRE initiative distinguished priority common basic data, needed to be harmonized and shared. These include the first three EUROSION key data sets, while the two other recommended data sets are included in the second level of priority INSPIRE data sets. These datasets are:

EUROSION recommended key data sets

INSPIRE data

1. The coastline.

2. Coastal elevation and bathymetry.

Elevation including terrestrial elevation, bathymetry and coastline (Annex I)

3. Hydrography. Hydrograpy/water catchments (Annex I)

4. Nearshore wave regime. Meteorological spatial features (Annex II)

5. Astronomical tides. Oceanic spatial features (Annex II)

Potential benefits of semantic European linkage

Benefit 1: Low-cost update of the EUROSION database and exposure assessment.

Experience has shown that the production of Europe-wide database – such as EUROSION - often results from one-time investments, little attention being given afterwards to updating mechanisms. Yet, it is highly predictable that the long-term cost of continuous data updating is far below the cost of replacing the whole database with a new one once it is completely obsolete. In that sense, Local Information Systems offer major opportunity to update these Europe-wide database at low cost since each local partner would be in charge of updating the small part of the database corresponding to its own region and would send its contribution back to the institution in charge of maintaining the Europe-wide database. One may argue that the Europe-Europe-wide database would then be updated in a piecemeal way; however we estimate that the negative effects of this piecemeal updating process could be attenuated by the implementation of “updating” standards to be respected by each LIS and a adequate

EUROSION identified 20 data groups layers and examined the up and down scaling potential. These layers are divided in four main groups.

For each of the data group layers the potential for upscaling from the local level towards European scale and the reverse downscaling process is described.

The physical environment includes: Shoreline, Wave

regime, Wind regime, Sea level, Bathymetry, Foreshore Characteristics, Sediment transport, Terrestrial elevation, Geology and Geomorphology and historical events.

Legal and policy data groups consist of: Land use,

Protected areas, Remarkable boundaries and land ownership.

Socio Economical layers: Population, Land cover,

Infrastructure, Economic activities and Market value.

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documentation of the final product. In particular, such a process would make it possible to update some of EUROSION database layers which cannot benefit from economies of scale. These layers include notably:

- the coastline geomorphology - the coastline geology

- the coastline evolutionary trends - the presence of defence works - the budget spent on coastal defences

Benefit 2: Provision of baseline data to regional authorities

If some regions already benefit from a huge amount of data, the situation can be quite different from one region to another. In particular, the experience of EUROSION has shown that some of the EUROSION database layers may be of relevance for regional authorities even if at a 1:100,000 scale. This is the case in particular for data on land cover (CORINE Land Cover), which combined with population data known at the municipal level, can provide a finer estimation of municipal population at risk along the risk (see for example the methodology developed by EUROSION for indicator 11 – population within the radius of influence of coastal erosion). Another example is given by the provision of data on offshore wave and wind regime (provided by EUROSION) which in turn can be transformed into near-shore wave and wind regime after combination with bathymetry and wave transformation models. These are clear illustrations that the availability of Europe-wide data may turn quite useful for certain local or regional applications.

Benefit 3: Ensure interoperability and comparability of local data

A number of applications require that data – though local – have a consistent structure and format Europe-wide. The conclusions of EUROSION, which recommend the establishment of a European map of coastal sediment cells, illustrate this requirement. The delineation of coastal sediment cell indeed requires that a consistent methodology based on same-structure data is adopted. Failure to do so will inevitably result in coastal sediment cell overlapping or coverage gaps, which in turn may biaise coastal sediment management planning process and related responsibilities. By “forcing” the local data to fit within a specific Europe-wide structure, the opportunities offered by the cross-combination of local data increase (as illustrated in the case of coastal sediment cell) and exchange of experience and methodologies become more efficient.

Future development

Further efforts need to be undertaken to:

A) Demonstrate the mutual benefits at the various administrative levels.

B) Develop a Europe-wide methodology for delineating coastal sediment cell boundaries on the basis of the key datasets.

Specific attention shall be given to the identification of sediment sources, sinks and circulation patterns. Characteristics and differences between the European Regional Seas need to be taken into account in this process. Both combining of existing and developing technologies and operational services (e.g. through GMES projects) should contribute to this process.

The challenge to meet such European standardisation benefiting at all administrative levels needs to be demonstrated through practical experience within a coastal sediment cell.

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E. DATA ARCHTECTURE MODELLING

The purpose of this section is to establish common requirements for modelling and documenting the architecture of data meant to be integrated into an “exemplary” local information system dedicated to coastline management. These requirements are intended for system architects, database designers, and software developers who will implement these requirements in different spatial data applications (e.g. GIS). These requirements facilitate: (i) interchange of data among data providers and users, (ii) maintenance operations to the information system, and (iii) further improvements to the information system.

To avoid confusion, these requirements do not impose or prescribe any particular architecture of the data themselves. Instead, they are meant to codify and formalise the various elements and steps – including for example terminology, modelling language, and documentation - which are needed to develop and implement a data architecture.

Finally, these requirements should be implemented for each Reference Topic meant to become part of the coastal information system. Reference Topics for coastal information system are listed in the section Data content requirements. Once implemented for each Reference Topic, these elements form a standard hereafter referred as a “Reference Topic Standard”. This means that in line with the rest of the documents, 31 reference topic standards should be developed in order to build a coastal information system meant to answer the critical questions asked in section A..

EUROSION proposes that data modelling in connection with the establishment of coastal information system are based upon the following requirements:

• Data modelling is undertaken on the basis of ISO/TC211 standards, and are described in accordance to the reference model ISO 19101:2002. The terminology used during the data modelling process should comply with the requirements of ISO 19101:2002 and, in particular with the standard ISO 19104 - Terminology.

• The Unified Modelling Language (UML) is used as the schema modelling language to define data interchange formats. Each of the 31 reference topic standards shall include an integrated application schema expressed in the UML according to ISO 19109, Rules for application schema, and its normative references. The application schema will specify, as appropriate, the feature types, attribute types, attribute domain, feature relationships, spatial representation, data organization, and metadata that define the information content of a data set.

• Each of the Reference topic standards shall contain, as appropriate, documentation of all features, attributes, and relationships and their definitions. A data dictionary table shall be used to describe the characteristics of the UML model diagrams.

• The standard for metadata, to be established in the framework of a coastal information system should comply with ISO 19115, Geographic information – Metadata. ISO 19115 includes a minimal set of metadata that is highly recommended to follow. This minimal set is provided hereafter:

ISO Elements

dataset title (M)

dataset reference date (M) dataset abstract (M) metadata point of contact (M) metadata date stamp (M) dataset language (M) dataset topic category (M)

geographic location (bounding box or identifier) (C) dataset character set (C)

metadata language (C) metadata character set (C) metadata standard name (rO) metadata standard version (rO) spatial representation type (rO)

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distribution format (rO) dataset point of contact (rO) lineage (rO)

online resource (rO) reference system (rO) dataset spatial resolution (rO) metadata file identifier (rO) extent (vertical) (rO) extent (temporal) (rO) Dataset purpose (O) Dataset progress (O)

Dataset Maintenance and Update Frequency (O) Access Constraints (O)

Use Constraints (O) Keywords (O) Dataset originator (O) Currentness Reference (O)

C - conditional M - mandatory O - optional

rO – recommended optional

Minimum set of metadata elements

• Data modeller refers to national spatial data infrastructures which have defined permanent feature identifiers. A permanent feature identifier is an attribute attached to an object of the real world (e.g. roads, river, administrative units) which is common to several GIS application. In that sense, using permanent identifiers makes it possible to combine data from different applications. It is of the utmost importance that during the design of the coastal information system, the data modeller is knowledgeable of these features which have a permanent identifiers established by national authoritative standards. The management of a common or "permanent" feature identity needs to be undertaken within the community with permission granted to certain participant organisations to create or adjudicate these identities.

F. DATA SPATIAL REPRESENTATION

The Earth is a very complex shape. Its surface is disturbed by mountain ranges and deep oceans. In order to map its geography, a reference system or model is needed which will allow such topographic irregularities to be recorded and any single point on the Earth to be located unambiguously. The problem is that a variety of reference systems exist, particularly in Europe, with the consequence that when combining or integrating data from different providers into a GIS, the various themes (inputs) are not in accurate alignment. To overcome these shortcomings, which may considerably undermine the overall quality of coastal applications, it is recommended that a number of standards are adopted by the various authorities willing to implement such coastal information systems. This section explains in detail the need for adopting common spatial reference systems.

• Geographical extent of the coastal information system. EUROSION strongly recommends

to implement coastal information systems at the level of coastal administrative regions extended to the boundaries of coastal sediment cells overlapping with the region’s extent. A coastal sediment cell can be defined as a length of coastline and associated near-shore areas where movement of sediments is largely self contained. Sediment cells are separated from each other by rivers and sometimes by large promontories where the direction of longshore drift is changing; the length of sediment cells may be very small (less than a kilometre) or very large (100 km).

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• Coordinate reference system. In line with the resolutions of European mapping agencies

and the European Commission, EUROSION recommends the adoption of ETRS89 for producing and archiving spatial data on European coastal zones. In that respect, it is worth mentioning that some institutions, such as the International Association of Geodesy (IAG) or Eurogeographics (www.eurogeographics.org) which federates the national mapping agencies in the European Union, provide the methodology and the parameters needed (7 parameters) to convert coordinates from any coordinate systems into the system ETRS89.

• Vertical Reference System. In line with the resolution of IAG and the European Commission,

EUROSION recommends the adoption of EVRF 2000 as the vertical reference system for altitude related to spatial data in the European coastal zones. EVRF 2000 is characterised by : - the datum of “Normaal Amsterdams Peil” (NAP)

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Service contract B4-3301/2001/329175/MAR/B3 “Coastal erosion – Evaluation of the need for action” Directorate General Environment

European Commission

Living with coastal erosion in Europe:

Sediment and Space for Sustainability

Organisational and management aspects

of coastal information

Final version – 20 May 2004

National Institute for Coastal and Marine Management of the Netherlands (RIKZ) EUCC – The Coastal Union IGN France International Autonomous University of Barcelona (UAB) French Geological Survey (BRGM) French Institute of Environment (IFEN)

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CONTENTS... 3

1. INTRODUCTION... 5

2. ROLE OF COASTAL INFORMATION IN DECISION MAKING... 6

2.1 Findings from the pilot sites ... 6

2.2 Hazards and Vulnerability: an introduction to risk mapping... 13

2.3 Coastal information systems in the EU: examples ... 17

2.4 The role of Geographic Information Systems (GIS)... 18

3. LIS PROCEDURES AND PRACTICES TOWARDS IMPLEMENTATION ... 20

3.1 Overview of procedures... 20

3.2 Best practices ... 21

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1. INTRODUCTION

Management of the coastal environment needs more attention than ever before in view of the growing coastal population and anthropogenic impacts. Disciplines like environmental sciences, civil engineering and socio-economics are moving towards each other to form local, regional or even European interdisciplinary groups for joint problem solving.

The major groups involved in environmental planning are authorities (policy- and decision makers at different levels), scientists and engineers (design and evaluate planning variants) and entrepreneurs (implementation). Other stakeholders are the users, the general public, non-governmental organisations, private companies, pressure groups and the media.

Information systems facilitate information sharing for the achievement of mutual program or administrative goals. These systems address both individual and common needs and result from ongoing discourse among stakeholders, such as the ones mentioned above.

In the 1960’s and 1970’s information systems were used as tools for data processing, in the 1980’s their role evolved to that of systems that supported stakeholders needs and take better decisions. Presently we see their role change to “strategic” that is systems that support a variety of players in different organisations, at different levels of government, in different locations, and sometimes in both the public and private or non-profit sectors.

What is a local information system?

An information system (IS) can be defined as “a set of technological, human, organisational, financial, and information resources organized in such a way to produce, archive, retrieve, modify, process, combine, represent, exchange and/or disseminate information with a view to reach the objectives the system is designed for”.

By local information system, and with reference to the above mentioned definition, we mean that the objectives for which the system has been designed for, relate to a restricted geographical area, ranging from a municipality to a regional entity.

Although a number of other IS definitions tend to put the technology upfront (computer-based), it is essential to understand that institutional, organisational and political aspects account for the greater share in the success (or failure) of an information system.

Consequently, developers of information systems are expected to cooperate with partners in economics, sociology, and engineering as well as with experts of natural, earth and life sciences, and computer sciences. These guidelines are to support these developers, and aims to be covering all aspects of the implementation of a local information system. Although not all of these aspects are necessary because of the enormous variation in local conditions, but the relevant parts may be selected during a step-wise implementation process, accompanied with clear technical specifications.

However, critical success factors for information systems are no secret: top management support, clear purpose, committed stakeholders, and realistic cost and benefit measures are just a few that contribute to a successful system. These factors are well known, but not easily achieved, even in systems that lie inside the boundaries of a single organisation.

The only justification for any information system, or particular component, is that the benefits justify the costs. Those benefits must be identified, being justified not only in monetary terms but also considering e.g. improvement of access to information, awareness and a clearer sense of involvement amongst stakeholders, and finally, the support and efficiency it brings to the whole cycle of policy preparation, implementation and evaluation

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2. ROLE OF COASTAL INFORMATION IN DECISION MAKING

During the study, 11 pilot sites have been reviewed according to the following methodology:

Step 1: Documentation and collection of background information of the following aspects:

• the physical and environmental context

• the policy and institutional framework

• the socio-economic profile

• the technical measures implemented

• the social perception

• the information management practices

Step 2: Review and analysis of decision-making processes and the role of information in these processes. This includes a review of models, tools, and instruments for planning, implementing and monitoring actions. This also included a review of the communication level among stakeholders, public information and mechanisms for conflict resolution.

Step 3: Synthesis (findings) and recommendations for improving information management practices and elaboration of guidelines for implementing decision-support information systems.

Step 4: Development of a prototype to experiment and assess the relevance and feasibility of the guidelines elaborated in Step 3.

2.1 Findings from the pilot sites

Finding no.1 - A clear distinction should be made between information and data, though most of the people met in the pilot sites considered and used them as synonyms. To clarify the distinction, one can say that data is factual information, especially that used for analysis or reasoning. Data on its own has no meaning, but becomes information when it is interpreted. Information is a collection of facts or data. The distinction is all the more important since most of people met agreed on the relevant data to be collected and shared at the local level (e.g. heights and period of breaking waves) but could not agree on the information to be derived from such data, information being directly related to the specific concern of each stakeholder.

In that perspective, lessons learned from the pilot studies revealed that stakeholders could be grouped in 5 categories, each of these categories defining a set of information pieces reflecting the community of concerns shared by all the members of this category.

Table 1. Stakeholders and information needs

Stakeholders’ category

Concerns Information needs _{Needs fulfilled ?}

Local authority executives (e.g. mayors)

• Make the “right” decision and be accountable for it

• Allocate budget according to priority for coastal erosion

• Technical feasibility studies • Cost-benefit assessment studies • Environmental impact assessment studies • Public hearings • Shoreline management practices elsewhere • Knowledge of areas Yes No Partly Partly Partly Partly

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management • Make decision conform to local, regional, national, European regulations and policies

• Solve conflict among stakeholders

at risk of coastal erosion

• European, national and regional (if applicable) legislation, • Policy documents • Respective interests and opinion of stakeholders Partly Partly Representative of regional authorities (if applicable) • Conformity of coastal erosion management decision with the regional legal (if applicable) and policy framework • Elaborate regional development master plans • Allocate budget according to priority for coastal erosion management • Monitor the implementation performance of the regional development master plan

• Legal and policy frameworks • Environmental impact assessment studies • Understanding of physical and environmental processes • Knowledge of areas at risk of coastal erosion • Reporting of municipal actions Partly Partly Partly Partly Partly Representative of national authorities • Conformity of coastal erosion management decision with the national legal and policy framework

• Allocate budget according to priority for coastal erosion management

• Monitor the implementation performance of national policies

• Legal and policy frameworks • Environmental impact assessment studies • Knowledge of areas at risk of coastal erosion • Reporting of municipal and regional actions Yes Partly Partly Partly Coastal engineers

• Optimise the design of coastal structures (both technically and financially) • Understanding of physical and environmental processes • Modelling tools Partly Partly Partly

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• Measure

effectiveness of the coastal structure and detect erosion problems on time

• Monitoring tools

Private entrepreneurs

• Reduce financial risk in case of coastal erosion

• Mitigate the impact of their activities on the coastline environment • Knowledge of areas at risk of coastal erosion • Environmental impact assessment studies • Shoreline management practices elsewhere No Yes No Environmental lobbies

• Influence the design of coastal structures towards less damage on the environment • Information of planned coastal projects • Environmental impact assessment studies No No General public • Feel safe • Defend local economy at risk of coastal erosion • Defend cultural heritage • Improve quality of life (including recreational activities) • Knowledge of areas at risk of coastal erosion • Knowledge of economic assets at risk of coastal erosion • Knowledge of

heritage areas at risk of coastal erosion • Reporting of municipal actions No No No Partly

Based on this table, it appears however that adequate knowledge on areas at risk of coastal erosion appears is a recurrent information need for all stakeholders, and should therefore be addressed as a priority in the design of local information system.

Finding no.2 - Needs for information remain in general partly or poorly fulfilled according to the stakeholders. However, in most cases, this does not mean that the information does not exist but that a category of stakeholders experiences troubles to localize and retrieve, or simply does not know that is information is easily accessible. Quite illustrative examples are legal and policy documents which in most cases are accessible via internet (E-governance programs in Sitges, or Holland). The table also confirms that stakeholders’ information needs (with exception to coastal engineers) concern access to analyzed and aggregated data put into context and commented through studies, reports and maps, rather than data themselves.

Finding no.3 - In making the distinction between information and data, it also appeared clearly that the local stakeholders expressed their wish to access some specific data (e.g. LIDAR survey in Aquitaine, near shore bathymetry in Aveiro) without having the appropriate technology to use it or without knowing a priori how they will use such data in their daily practices. In that sense, the overall

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assessment of information and data needs seemed to be clearly technology-driven and not practical-minded. It also appeared quite clearly that whenever pilot sites have the right technology to process high technological data (e.g. Isle of Wight, Holland), they have also established the appropriate conventions with data providers to access these data, which suggests that access to existing data is a question of “knowledge and know-how” and not a technological problem.

Finding no. 4 - In a significant number of cases, poor access to important documents is reported as a refusal or reluctance from the information provider to release the information. This may be true in a number of cases, but it should be noted that the lack of dissemination mechanisms (such as a information resource centre, or a virtual library) at the level of the information provider accounts for important delays in releasing information. It is therefore not a matter of reluctance but of dissemination capacities. This has led anyway in many cases to defiance and conflict. It therefore appears that access existing information and data is primarily hampered by political, organizational and institutional obstacles and not by technological shortcomings. As a consequence, design of Local Information Systems should focus at first to the establishment of an institutional platform among stakeholders that would facilitate the release of key information, key documents and key data. An adequate technology should be then suggested to back this institutional platform (and not the contrary)

Table 2 summarizes such generic data relevant to understand and manage coastal erosion and provides a short rationale of their importance for future local information system, as well a brief description of their associated sources, models and tools. This list can be considered as a list of “frequently asked data” and may be completed according to more specific needs (e.g. impact of beach nourishment on benthic fauna as in Holland for example which require data on benthic fauna composition and distribution along the shore). A more complete overview of how these different data sets interact and with which scale and time pattern is provided in figures 1, 2 and 3.

It is of course impossible for EUROSION to address the wide variety of information needs related to coastal erosion needs. However and in line with the findings from the pilot studies, the connection between information and data can be best illustrated using the example of coastal erosion risk assessment and mapping.

Table 2. Description of key datasets for the coast

DATA GROUP DATA JUSTIFICATION

ASSOCIATED SOURCES, TOOLS AND MODELS PHYSICAL ENVIRONMENT

Shoreline • Current position of the shoreline

• Historic position of the shoreline

As the interface between land and sea, the shoreline constitutes the most important object to be known and monitored. Its evolution in time is crucial to anticipate problems and project scenarios.

It is recommended to define the shoreline as the upper reaches of the highest waves (other than storm waves) occurring during the highest tides (spring tides). This definition makes it clear that the shoreline is a dynamic entity since this upper limit varies from one year to another. For convenience, most European countries have defined the shoreline as the “mean value” of this upper limit as measured over several years.

A number of techniques make it possible to delineate the shoreline position. It may be:

- interpolated from transect profiles, i.e. the “probable” position of the shoreline is deduced from the position of the shoreline accurately known at certain locations along the shore.

- derived by intersecting the highest water level (other than storm level) known at a certain location with an accurate elevation model produced from remote sensing technologies (mainly LIDAR or aerial photogrammetry)

Historic shoreline positions may be derived from old topographical maps (e.g. in France Carte de

l’Etat Major, 19th_{century) or old}

aerial photographs (since 1950).

Wave regime • Near-shore wave heights

Waves breaking in the surf zone liberate energy which in turn scour

The CERC equation (Komar, 1986) determines the energy of

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ASSOCIATED SOURCES, TOOLS AND MODELS

heights

• Near-shore wave periods

• Near-shore wave directions

liberate energy which in turn scour and transport sediments from the seabed. Wave energy is a function of wave height and period. In addition, the angle at which the waves break determine the alongshore sediment transport process

1986) determines the energy of waves breaking in the surf zone and estimates the longshore sediment transport. Knowledge of the sand grain size is requested to solve the CERC equation

Wind regime • Off-shore wind speed (10 meters above sea surface)

• Off-shore wind direction

• Near-shore wind speed • Near-shore wind

direction

The wind blowing over the sea causes an elevation of the water level (wind set-up). This elevation is a function of the wind speed, the water depth, the air density, and the atmospheric pressure. Offshore winds contribute to the generation of an offshore wind set-up that then travels across the sea. As for local winds, they c ontribute significantly to the generation of waves and local wind set-up. Local winds are also responsible for aeolian erosion of dunes.

Formula of Wu (1980) , so called “wind stress equation” provides a good estimate of the wind set-up which in turn can be used to predict a storm surge level. Knowledge of the bathymetry and the fetch (extent of water upfront the coastline) is requested to predict the storm surge level via the formula of Wu.

Sea level • Tidal range

• Relative sea level rise

At high tide, the assaults of the waves are brought to higher level. When a storm surge coincides with a high tide, the impact of the sea is maximal on the coastline and may for example result in the complete erosion of the coastal dunes, leaving the hinterland undefended against flooding.

As for sea level rise, its effects are particularly visible on coastal lowlands (e.g. salt marshes, mud flats). Relative sea level rise should be preferred since it includes the effect of land subsidence.

Astronomic tides are derived from well-known harmonic coefficients calibrated using world wide tide gauges.

Sea level rise can also be derived from a network of tide-gauges (it is recommended to use then data coming from harbour tide gauges)

Bathymetry • Off-shore bathymetry • Near-shore bathymetry

In general, off-shore bathymetry has limited use for coastal erosion processes. Howver it makes it possible to determine the wind set-up generated by off-shore winds. As for nearshore bathymetry, it plays an important role in the behaviour of waves and associated currents. As waves travel shallow waters, they undergo a number of

transformations including wave shoaling, refraction and diffraction, which result in a change of wave direction and heights.

Near-shore bathymetry may be either obtained from national hydrographic services, or obtained through surveying techniques. One can distinguish three major type of surveying techniques: (i) ship-borne surveying (Sonar), (ii) airborne surveying (SHOALS), and (iii) ground-based profiling. SWAN (Simulating Waves Near-shore) is undeniably the most commonly used model of wave transformation in shallow waters.

Foreshore characteristics

• Sediment grain size • Foreshore slope

A relation exists between the water level, the foreshore profile, and the sediment characteristics (grain size). The grain size is a key parameter which is needed to model sediment transport or the coastline response to sea level rise or storm surge.

The Bruun rule (1962) helps predict the profile (slope) of the foreshore as a func tion of the grain size and water level. The impact of sea level rise

Sediment transport

• Net sediment transport • Rip currents

• Long-shore drift • Ebb and flood currents

Sediment transport is a key element of coastline evolution. Sediments are scoured from the seabed or taken from collapsed cliff debris and transported in other places. At each individual location, the balance between incoming sediments and outgoing sediments (the “sediment

Net sediment transport may be derived from the CERC equation (see above). It can also be measured directly using sediment “traps” disposed at certain locations.

Other models such as UNIBEST make it possible to predict

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outgoing sediments (the “sediment budget”) determines whether the coastline will erode or not. Understanding sediment circulation patterns within a same coastal sediment cell also helps predict the impact of coastal engineering structures at the lee-side (i.e. down-drift). This is valid as well for tidal currents which significantly contribute to offshore/onshore transports in the sediment cell.

make it possible to predict sediment transport for sandy coasts. Terrestrial elevation • Terrestrial elevation • Contour lines (alternatively)

Terrestrial elevation is particularly important to delineate flood-prone areas as a result of coastal erosion.

Elevation may be derived from a number of remote sensing techniques including laser scanning (LIDAR) or aerial photogrammetry which both give highly accurate results.

Geology and geomorphology

• Geo-morphological patterns

• Geological patterns

Geology determines the resistance of the substrate to the assaults of the sea. By way of illustration, chalk is more subject to erosion than granit.

Historical events • Storm records • Landslide (in the case

of cliff)

In most cases, calculating an annual erosion rate does not reflect reality: for example, coastal cliffs retreat as a result of landslide events which may occur every 5, 10, or even 40 years (but with a relatively regular pattern). In a number of cases, it may be therefore more convenient to record events. The same goes for acute erosion induced by major storms.

LEGAL AND POLICY FRAMEWORK

Land use • Land use zoning Land use plans specify what the various land parcels should be dedicated to. They specify as well what kinds of operations are authorized and what kind of operations are not authorized (e.g. building). They also help quantify land-based pressure on the coast such as hotel resort construction or industrial development, and provide a good proxy of economic assets at risk.

Land use plans are generally established at the level of the municipality (see also land cover)

Protected areas • Protected areas EU and national regulations define a number of measures to protect some areas of high ecological value. These areas include NATURA 2000 sites, RAMSAR sites, National Parks, Regional Parks, Biosphere reserves, etc. In that sense, potential effects of development projects on coastal erosion processes susceptible to impact such protected areas must be investigated.

Remarkable boundaries

• Remarkable boundaries

Remarkable boundaries other than protected areas – for example setback lines, limits of public domain, cultural heritage sites – are important features to take into account as well.

Land ownership • Land ownership zoning One can distinguish the private domain (extended to the State private domain and the municipality

Land ownership patterns do not generally exist as such. They can however be derived from

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private domain and the municipality private domain) and the public domain. Through an adequate land tenure policy, decision-makers can minimize uncontrolled coastal development which would impact coastal erosion processes. Knowledge of the land ownership patterns is therefore important

however be derived from cadastral plans.

SOCIO-ECONOMIC PROFILE

Population • Population of coastal municipalities

• Population living within 100 meters from the shoreline

• Population living within 1 kilometer from the shoreline

Land cover • Land cover Contrary to land use which defines land parcels according to their usage or anticipated usage, land cover provides information on the nature of the land surface regardless of its usage. However in practice, land cover can be considered as a proxy of land use, if land use is not available. Land cover can enter the assessment of assets at risk.

Such existing programmes as CORINE Land Cover provide land cover data at scale 1:100,000 which might not be sufficient for local applications. However the methodology implemented by CORINE Land Cover can be adapted at a higher scale (e.g. 1:25,000)

Infrastructure • Roads • Railways • High voltage lines • Energy plants (nuclear,

windfarms, hydro) • Harbours

• Jetties

Infrastructure enter both the assessment of economic assets at risk but also the assessment of pressure on coastal sediment transport processes

Infrastructure may be derived from aerial photographs

(orthophotographs) if not available via existing topographical database (NB: National Mapping

Agencies are in charge of maintaining such an information with an adequate accuracy) Economic activities • Dredging license boundaries and volume dredged • Fishery license

boundaries, annual fish captures, and employment • Aquaculture and agriculture farm boundaries, annual production, and employment • Seasonal population (tourists)

• Hotel nights within 1 km of the coastline

Economic activities enter both the assessment of economic assets at risk but also the assessment of pressure on coastal sediment transport processes

Market value • Market value of built residential m2 within 1 km from the coastline • Market value of built

commercial/industrial m2 within 1 km from the coastline • Market value of non

built m2 within 1 km from the coastline

Market values are highly sensitive to changes in the local environment (e.g. reduced beach width resulting in reduced tourist frequentation). In addition, they are relevant to assess “capital” at risk, and make simulation before implementing managed realignment.

Local federations of notaries are undeniably the best sources for such data. TECHNICAL MEASURES Coastal erosion management operations • Geographical extent of coastal erosion works

Coastal erosion management operations are direct response to coastal erosion problems. An