Integrated Mapping of the Coastal Zone of Britain: The ICZMap Project

Matthew Harrison (1), Ceri James (1), David Overton (2), John Pepper (3)

(1) British Geological Survey, Keyworth, Nottingham (UK)
(2) Ordnance Survey, Southampton (UK)
(3) The United Kingdom Hydrographic Office, Taunton, Somerset (UK)

Abstract
The coastal zone is a highly dynamic environment with importance for economic, environmental, cultural and recreational activity in the UK. Under recent European Parliament recommendation (2002/413/EC) integrated coastal zone management will assume a greater importance for member states.

The Integrated Coastal Zone Mapping project (ICZMap) is a joint, UK Government funded project undertaken by the Ordnance Survey (OS), the United Kingdom Hydrographic Office (UKHO) and the British Geological Survey (BGS). The objective of ICZMap is "to provide a unified digital base map of the coastal zone of Great Britain, combining both onshore and offshore features." The creation of this dataset over the past two years has been a major undertaking by all three organisations. It has required the organisations involved and the steering group to work closely together to understand what each body is capturing in the field, the update cycles of data and then how these feed into workflows and map creation. Part of this process has been a series of workshops and presentations in England, Scotland and Wales, held to involve stakeholders and encourage participation in the development of the ICZMap framework.

Following two years of collaboration since it's introduction at CoastGIS '01, some of the results and conclusions of ICZMap are reported. This paper will give an overview of the results of the whole project and then focuses in more detail on some of the work that BGS undertook as their direct contribution to the project.

Introduction
The ICZMap project was initiated in April 2001 as a joint venture by the Ordnance Survey, the British Geological Survey and the United Kingdom Hydrographic Office. It was funded within the United Kingdom Government Treasury Invest to Save Budget programme (ISB) and was completed in June 2003.

The project's aim was to enable the integration of terrestrial and marine geographic data held by the three organisations, so that these could be accessed readily by users, to satisfy diverse coastal zone applications and services.
Although there has been co-operation and long-standing links between the three organisations over many years, prior to ICZMap, there had been no attempt to integrate the three organisations' datasets across the coastal zone apart from the publication of a printed coastal map in 1990 covering only a small area. This initiative was not taken forward as a published map series. However, since that time there has been an increased awareness of the value of our coasts and the pressures which impact upon them. Integrated mapping of the coastal zone is a primary requirement for the sustainable development and stewardship of the coast. ICZMap was instigated as a response to this requirement.
About a third of the population of the UK live within 10 km of the coast. The coastal zone of the United Kingdom is diverse in terms of its physical features, natural habitat, economic development, social character and community value. It lies at the interface between the marine and terrestrial environment and has pressures and drivers, which are specific or unique to itself.

Project Drivers
The potential effects of climate change in the coastal zone are significant. The scenario for climate change in the UK, published by the Department for Environment, Food and Rural Affairs (DEFRA) in 2002 indicated that average annual temperatures would continue to increase during this century. We will see generally wetter winters and drier summers, also storms may become more frequent. Sea level will have risen around much of the UK coast. In SE England it may reach over 80 cm above its current level by the 2080's. Extreme sea levels associated with the combined effects of high tides, sea level rise and storms may occur more frequently. As a result the coastal zone could experience:


The UK Government is committed to monitoring and assessing the impacts of climate change and funding research and solutions with regard to coastal erosion and flooding. ICZMap has an important role in supporting this commitment.

The Government's new strategy for the conservation and sustainable development of our marine environment, including the coast, was published in the DEFRA report 'Safeguarding our Seas' in May 2002. The strategy outlines a vision of a marine environment that is clean, healthy, safe, productive and biologically diverse and will be achieved by adopting an eco-system-based management approach. The report outlines the principles which underpin the policies but more importantly, sets out how the government will work to achieve their vision by developing new ideas and initiatives, particularly at the cross cutting level.

Some of these initiatives include:

Some of the initiatives outlined above require the development of an ICZMap dataset across the UK if their goals are to be achieved.

A primary initiative within the Government's strategy on Marine Stewardship is the commitment to take forward the new EU Recommendation on integrated coastal zone management (ICZM). The recommendation was adopted in May 2002 (2002/413/EC). Member states have to undertake a national stocktaking of legislation, institutions and stakeholders involved in coastal management and, based on this, develop national strategies to implement ICZM. The stocktaking began in the UK in March 2003.

Some of the national strategies to be developed should:

In implementing integrated coastal zone management in the UK the development of ICZMap as an integrated geographic dataset is a primary requirement to meet the demands of the national strategy

The management of flood and coastal defence in England and Wales has included, since 1993, the development of Shoreline Management Plans (SMPs) as a planning tool. The first round, which covered the whole coastline of England and Wales was completed in 1999. Maps and data from the Ordnance Survey, British Geological Survey and the UK Hydrographic Office were used in the first round of SMPs. However they were used in an ad hoc fashion by the various consultants who compiled the SMPs with no systematic consistency with regard to scale, detail or data gleaned from the OS, BGS or UKHO.

Guidance and testing for the next round of SMPs is currently under way. There is an attempt to provide a consistent methodology for this new round. ICZMap could provide an integrated dataset as a primary layer for the next round of SMPs. However it would require investment and funding to roll out ICZMap for the whole of England and Wales.

There is a growing band of European legislation and directives, which impact on the coastal zone. As well as the recommendation on Integrated Coastal Zone Management described above, these include:

ICZMap data would be a primary requirement for many of the tasks associated with implementing the criteria and standards associated with this legislation.

The Government recently established a Review of Marine Nature Conservation to evaluate the success of voluntary and statutory marine nature conservation measures and identify examples of best practice. One of the interim recommendations of the Review was the implementation of a Regional Seas Pilot based on the Irish Sea. One of the tasks of the pilot was to gather as much physical data as possible within a GIS. In its interim report in the summer of 2003 it looked at the type of data it acquired, its availability, ease of use and integration into the GIS. It noted that it had been unable to acquire an integrated coastal dataset and this was a major deficiency within the GIS and detrimental to the value of the Pilot in mapping and identifying areas of potential marine nature conservation.

Coastal Fora and Groups have been initiated around the coast of the UK. They have a wide range of membership including national and regional organisations, planning authorities, local groups and stakeholders. They hold regular meetings and encourage debate and research on coastal issues. They are involved in developing coastal strategy and have become significant local and regional partnerships with a strong and co-ordinated voice.

Primary users of coastal data are members of Coastal Fora who have long championed the requirement for integrated data in the coastal zone. They and the projects Steering Group have been actively engaged in ICZMap and in evaluating and testing ICZMap data. In particular those involved were:

Objectives of the Project
The projects aims were "to provide a unified digital base map of the coastal zone of Great Britain, combining onshore and offshore features". This was achieved by developing integrated data in three pilot sites in; the south coast of England, Milford Haven and the Firth of Forth as shown in figure 1.

Views from the potential market were sought throughout the project with numerous presentations and workshops.

The strategy was to:

  1. Develop an agreed specification.
  2. Give presentations and exhibitions to garner views and ideas from the user community.
  3. Develop pilot datasets.
  4. Release pilot datasets, presentations and exhibitions.
  5. The recruitment of users through established communities of stakeholders in pilot regions (Coastal Forums)
  6. Hold workshops sessions with groups of users prior to the release of a questionnaire.
  7. Recruit expert users for face-to-face meetings to discuss the data and requirements.

The data would be made available to end-users in a variety of forms and by a variety of electronic means.

To provide an overview a Steering group was specifically selected to encompass both commercial and government requirements and a management group was set up to reference the original objectives and project plan made and updated throughout the project in regular meetings.

Data
Currently BGS, OS and UKHO produce many digital datasets that provide mapping for onshore and offshore areas.

BGS currently produce published map series, which cover the onshore (DiGMap) and offshore (DiGSBS and Offshore Solid) geology of the UK separately. It is only for some small-scale maps, = 1:250,000, and a few geological themes that the onshore and offshore are integrated in single maps. This is the case for a number of reasons. Traditionally within BGS the onshore and offshore have been treated separately in terms of programmes of work, survey methods, data management and map products. Although there was some experience of merging larger scale onshore and offshore geological datasets within BGS this had not been done systematically. The ICZMap project allowed a focus on methods and procedures for integrating the primary geological digital mapped datasets produced by BGS for the onshore and offshore, matching them with OS and UKHO data.

For Ordnance Survey the Research and Innovation Group were responsible for developing the ICZMap concept and the OS data that was to be included within ICZMap. Originally OS envisaged that automatically generalised data, based on Ordnance Survey MasterMap® (OSMM), would be used within the ICZMap. However, it was finally agreed that OSMM data would be used in its standard form. Height data down to Mean Low Water (MLW) was provided from Landform Profile. OSMM is the organisations' premier digital dataset. It is available for the whole country at 1:1250 scale in urban areas and 1:2500 in rural areas. OSMM is the highest resolution data available from all three organisations and it was decided to use OSMM MLW and Mean High Water (MHW) as agreed boundaries to the data of each organisation.

The UKHO supplied data for the offshore component from the current Electronic Navigational Chart (ENC) data production flow line. No new ENCs were created, not all feature classes were required by the project and the data was filtered in order to supply only those usage layers required. ENC data is produced in accordance with the International Hydrographic Organisation (IHO) S-57 transfer standard for digital hydrographic data. S-57 ENC data has been developed for the offshore navigational market. ESRI Shape and MapInfo Tab file format data has been supplied in ICZMap to meet the requirements of the non-navigational coastal data user. Bathymetric height data are also included in ENCs and thse have been included in the ICZMap pilot relative to two height datums, Lowest Astronomic Tide (LAT) and Ordnance Datum (Newlyn) (ODN).

BGS Results
The ICZMap project has required the participation of a number of individuals from a range of programmes in BGS including Integrated Geoscience Surveys (Southern and Northern Britain), Continental Shelf and Margins, National Geoscience Information Service and Publication Production, as well as Coastal Geoscience and Global Change.

A series of technical meetings and business meetings were convened with UKHO and OS. Progress was also reported within BGS and internal meetings were convened to address issues, set goals and move the project forward.

Establish User needs and Data Specification
Project partners used conferences and workshops as fora to publicise the ICZMap project and populate a contacts database for the project. BGS used information gleaned from coastal projects, which it has undertaken including Shoreline Management Plans to inform ideas about user requirements.
BGS undertook a review of the offshore and onshore datasets that were available for ICZMap within BGS and a list of suitable datasets was agreed. The specifications and attributes of the agreed datasets were scrutinised for any issues that required resolution to make the datasets compatible internally and with OS and UKHO data.

The issues identified for BGS data in the coastal zone during this process included:

These issues were addressed during the ICZMap project and the results, where applicable, were included in the data prepared for the pilot areas

Data Preparation
The first task was to extract data for the onshore DiGMapGB-50 database and the BGS offshore database for the 3 project areas. These were for:

Onshore Data

Offshore Data

All the onshore datasets are held in British National Grid coordinate system. Offshore datasets we re-projected from their stored coordinate system of Universal Transverse Mercator Zone 30(N), International 1936 spheroid using Safe Software's Feature Manipulation Engine (FME).

Within the current DiGMapGB-50 product, the land-sea interface depicted is described as being MLW of the age of the topography as originally mapped, on a sheet-by-sheet basis. This leads to two kinds of problems when integrating DiGMapGB-50 sheet data seamlessly and with other datasets at the coast. These are:

The interface varies between sheets (figure 2)

The interface does not align with modern topographic mapping, something data users often want (figure 3).

Fig 2 Example of MLW interface shown in DiGMapGB-50 bedrock. The red circle highlights the difference due to the age of topography between two sheets on the Isle of Wight (©NERC 2003)

Fig 3 Example of OS 1974 MLW interface as shown in DiGMapGB-50 Bedrock alongside a modern OS Mastermap® MLW boundary (©NERC 2003 ©Crown Copyright All Rights Reserved)

In both instances this is because the MLW used as the boundary of the geology in DiGMapGB-50 is of the same age as the topography that the geology is based upon.

As part of the ICZMap project, BGS updated the MLW boundary in the pilot areas to that which is currently depicted in OS Mastermap®. Although this does bring technical problems regarding the integration of a high-resolution (1:1250 and 1:2500) MLW with DiGMapGB-50 (1:50000) scale geology we believe that these are outweighed by the increased utility to users of BGS DiGMapGB-50 geology at the coast (figure 4).

For this process to be undertaken, BGS required a clean and coherent MLW line, which was not available as standard in OS Mastermap®. After consultation with OS it was decided that BGS produce a new version of the MLW for use within the ICZMap pilot areas. This was then used to update the MLW of all the DiGMapGB-50 geology layers.

Fig 4. Example of the BGS ICZMap product. The geological classification, within the limitations of the resolution, meets seamlessly across the coastal zone. (© NERC 2003)

Historically, onshore and offshore surveys in BGS have been predicated on a number of factors including; the availability of data, its resolution, the ability to sample and identify rocks and sediment, and delimit boundaries and classification for different users. The greater detail of onshore survey compared to offshore survey is a reflection of the difficulty and complexity of offshore surveys. In shallow nearshore areas from MLW to approximately 10 m water depth there is an almost complete lack of geological data. In practice this means that geological classifications and boundaries have not matched up across the coastal zone. Part of the pilot project for BGS was to re-assess this situation and attempt a more seamless classification across the coastal zone, within the limitations of data resolution and support. This work was done across the MLW boundary in each of the pilot areas.

Once onshore and offshore data met at MLW from a cartographic perspective, geological re-interpretation was undertaken to integrate the geological boundaries between the larger scale onshore and offshore geology.

Littoral Mapping
In terms of beach classification, BGS undertook a sub-project to map the observed sediment around the Isle of Wight in the littoral zone. Neither BGS DiGMapGB-50 nor, OS Mastermap® include any detail about beach sediment, although this is depicted on OS 1:25000 mapping. It was the BGS project team's knowledge that this 1:25000 scale mapping is widely used for coastal studies such as habitats and SMPs. In an attempt to improve on the currently available data BGS trialed a rapid mapping technique using ArcPad GIS, handheld computers, GPS and aerial photography from the Environment Agency. Further details on this can be found in BGS Commissioned Report CR/03/007.

As part of this sub-project BGS had to build a foreshore polygon for the Isle of Wight from MLW and MHW, to form the seaward and landward boundaries of the field survey data. MHW line production was undertaken in a similar way to that for MLW.

The littoral zone between MLW and MHW was mapped using a classification based on four main components of beach sediment (sand, mud, gravel and boulders) with additional classes for rock platform and man-made deposits.

The use of a new OS Mastermap® derived MLW for ICZMap, has allowed the seamless integration of the Littoral Zone mapping with the ICZMap specification DiGMapGB-50, to produce a complete, integrated geological picture in the coastal zone for the Isle of Wight.

This new data was shown to various stakeholders as an addition to the full pilot dataset. The data was well received by Coastal Forum members and has been made into a CD/Internet GIS project that can be viewed in the future as market research for potential future ICZMap compliant products.

Discussion and Conclusions
Through ICZMap it proved technically feasible to join datasets from Ordnance Survey, British Geological Survey and UK Hydrographic Office across the coastal zone. However, consideration had to be given, as to what it would be possible to achieve at a national scale, at every stage, within a reasonable time frame. This proved one of the hardest parts of the project.

Users found ICZMap data a major improvement in mapping of the coastal zone. It is well seen that there is a user requirement for this data; 85% of those asked would find the combined data useful, and an indicative proportion of those who used the data were supportive in its application to Shoreline Management Plans. This enthusiasm has lead in turn to it's own problems, expectations in the marketplace about what could be achieved in the timescale by the three organisations were unrealistic.

Feedback during the project highlighted the vital importance of the coastal zone to a wide and enormously diverse range of sectors. This feedback came from contacts made through the ICZMap website, presentations, exhibitions and workshops that were held throughout the lifetime of the project. These sectors ranged from disaster management groups for events such as oil spills, to wetland trusts and the military.

There is a requirement for agreed UK-wide Mean Low Water (MLW) and Mean High Water (MHW) lines derived from a maintained primary dataset for a variety of user communities. In addition to the user communities, BGS and UKHO require these lines to allow data from each organisation to meet cartographically across the coastal zone. Having these lines available would support future developments in the coastal zone.

The perception and use of digital coastal datasets varies with the needs and expertise of the users. There is no universal requirement with regard to many issues, including, delivery format, scale, horizontal or vertical datums. The practical implication of this is that for some user communities existing delivery formats may be a barrier to use. The highest resolution data brings other problems, those of the unsuitability of using high and low resolution datasets from different organisations to address the same issue. The user must understand the limitation and that each dataset is fit for the purpose it was created for. There are many issues surrounding horizontal datums (WGS84 or OSGB36) and vertical datums (ODN or Lowest Astronomic Tide (LAT)) that have not been discussed in this paper, these issues mainly involve OS and UKHO as onshore BGS maps are based on OS topography and offshore BGS maps are based on UKHO Bathymetry. Further detail can be found in the ICZMap completion report and further work regarding the height model will continue between UKHO and OS beyond this pilot project.

Lack of data within the nearshore zone between MLW and approximately 10 m water depth cause major constraints on full integration across the coastal zone. This issue is being addressed currently for mapping bathymetry and height in the coastal zone by a UK Treasury funded project called Integrated Coastal Hydrography. Some of the tertiary data from these nearshore surveys can feed into a geological understanding of the shallow seabed but further work is required before full geological surveys in this zone are possible.

From a BGS perspective, the results of the Littoral Mapping exercise have been positively received both internally and externally. Given a requirement and funding, this may be an exercise that BGS will continue. The rapid mapping techniques, using ESRI's ArcPad and IPAQ handheld computers are being pursued throughout the organisation currently.

It is shown that ICZMap would contribute to the delivery of a number of Government and European policies, initiatives and directives which impact on the coastal zone, however, rollout of ICZMap on a UK wide scale will require substantial investment and commitment on the behalf of the three organisations. This could only be embarked upon with the approval and sponsorship of the UK Government.

Acknowledgments
The authors would like to thank the many individuals who were involved in the work that is reported here, especially; Tony Margetson, Martin Whitfield, Nigel Rees, Sally Philpot, Catherine Poulton, Rob Armstrong, Tony Myers, Simon Gomm, David Capstick, David Russell, Robert Sharpe, Jon Wood and the Coastal Forum Officers of Dorset, Firth of Forth, Pembrokeshire Coastal Forums and the membership of SCOPAC.
This paper is published with the permission of the Executive Director, British Geological Survey.