This series contains datasets derived from the Coast Protection Survey of England (CPSE). The survey was originally commissioned in 1993 to gather information to help the former Ministry of Agriculture, Fisheries and Food (MAFF) discharge its functions under the Coast Protection Act 1949 in regard to coast protection defences. The survey was carried out for the first time in 1993-94. Annual updates were conducted in 1995-96, 1996-97 and 1998 respectively.
Each dataset contains data on defence lengths and coastal defence elements, while the datasets for the 1996 and 1997 updates contain data on 'Class 4' defence elements. The data is held, respectively, in Length, Element and Form_d tables.
The Length tables contain general information about coast protection defences and unprotected lengths of coast identified as 'significantly eroding'. This was done by dividing the coast into defence lengths, corresponding to lengths of coast identified as having one or more coast protection structures and/or significantly eroding coastline. Divisions between defence lengths were made according to the following criteria:
- Changes in the ownership of the primary defence within a defence length.
- Significant changes in the form of the defence.
- The limits of sections of coast determined to be significantly eroding.
- Significant changes in the geology or erosion rates of unprotected, significantly eroding coastline.
The Length tables in the CPSE datasets contain the following information:
- A numerical code for each defence length in the form abb/ccdd, where 'a' identifies the MAFF region of the survey; 'bb' identifies the region used in the National Rivers Authority (NRA) Sea Defence Survey; 'cc' is a code for the relevant local authority; and 'dd' is a unique identifier for each defence length.
- The location of the defence.
- The date when a site visit was conducted, the associate consultant which conducted the visit, and the initials of the staff member.
- Ordnance Survey grid references representing the start and end points of the uppermost main primary feature of the defence length.
- The length in kilometres to two decimal places between the start and end points of the primary defence
- The 'asset type' of the defence length, i.e. the main components of the defences in each coastal length (seawall, embankment, etc), including whether the coast was 'shore' (i.e. a naturally eroding coastline). Up to four possible components could be specified. A separate field (Natural) records if the primary defence was a natural defence.
- The crest level of the primary defence.
- The degree of exposure of the defence.
- The 'design standard' of the defence, defined as 'the return period for which the structure was designed'.
- The wave height in metres for which the defence was designed.
- The erosion rate for lengths of unprotected cliff and shoreline identified as 'significantly eroding'.
- Type of land use behind the defence length within the zone deemed to be at risk of erosion.
- Estimates of the numbers of domestic and commercial properties at risk.
- The reference port, i.e. the secondary port most applicable for the prediction of tide levels, identified from Admiralty Tide Tables.
- The highest and lowest astronomical tides for the defence length.
The 1995 and 1996 updates of the CPSE only required respondents to update data on defence elements, while the 1997 update only required the updating of data on 'Class 4' elements. Information on defence lengths was not systematically updated.
The Element tables in the CPSE datasets provide more specific information:
- The code for the defence length plus a two digit sub code for each defence element.
- Ordnance Survey grid references representing the start and end points of the defence element, and the length between these points in kilometres (to two decimal places).
- The type of structure which the defence element represented.
- The major constituent material of the defence element.
- The dominant geology/sedimentology of the element, the angle of slope to the horizontal, and the appearance of the cliff in cases where the 'structure' of the defence element was described as 'cliff/scarp' or 'beach ridge'.
- For man-made defence elements, a classification of the element's condition.
- The type of foreshore in front of the defence element, and an assessment of how the foreshore was changing with time (e.g. eroding, stable).
- The level of the foreshore in front of the defence element, and an assessment of the degree to which the integrity of the coast protection structure was dependent on a high-level foreshore.
- The year or the approximate decade when the element was originally constructed or reconstructed.
- An estimate of the residual life of the defence element in years
- The authority, council or body responsible for maintaining the defence element or for significantly eroding sections of coastline, and whether the element was maintained by a local authority.
- A classification of the priority of the defence element, calculated by a formula involving the purpose of the defence element, its residual life in years, and the benefit to cost ratio of the defence element.
- A classification of the urgency of maintenance works, based on the residual life of the defence element, whether it was in an urban or rural area, and whether the value of damage caused would be significant.
- Whether a photograph of the defence element had been supplied at the time of the original (1993-94) survey.
- Two supplementary report description fields where additional information about a defence element could be recorded.
The Form_d tables in the datasets for the 1996 and 1997 updates contain the data which respondents were asked to supply about defence elements whose condition had been classified as"Class 4": i.e. deteriorating defences likely to need capital works within the next five years. In both sweeps respondents were asked to update information on elements which had previously been categorised as Class 4, and to include data on elements which had entered the Class 4 category since the last survey.
The Form_d tables provide the following details:
- The code for the defence length plus the sub-code for the defence element.
- The 'policy status' of the element - i.e. the maintenance policy of the operating authority towards the element.
- If the policy status indicated that the structure had been abandoned as a coastal defence or that capital works were planned in the next five years.
- The estimated cost of capital works if works were planned within the next five years.
- Any additional notes relating to the defence element.
The datasets in this series are available to download. Links to individual datasets can be found at piece level.
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