Traditionally HERs have been based primarily on point, and/or polygonal data on maps, usually limited to specific findspots, buildings or monuments. This leaves parts of the landscape unclassified as to its cultural heritage. These blank spaces on the map may be perceived by those outside the sector as being of no or limited archaeological or historical value. In contrast, the HLC is a total coverage model, although at present it covers primarily the rural landscape. HLC has developed in response to changing outlooks and new government policy.
Using a range of sources, primarily cartographic, HLC assesses and classifies the current landscape in broad historic terms, on the basis of a combination of morphology and interpretation. HLC provides an audit of what has survived within the current landscape, expressed in terms of its historic origins and development. The precise classification and methodology used varies between counties and regions (for more details see ''Taking Stock of the Method'' - Aldred and Fairclough 2003), but the basic principles are similar: a pre-defined series of specific HLC Types or broader Character Types which can be grouped into broad categories based on for example urban, enclosed landscapes and woodlands. The important characteristic is that a time or period element is incorporated. Without placing any hierarchy or value on this analysis it enables an HER to assess what has survived, from what period, so that it may be managed appropriately.
For LCA the landscape is assessed in terms of topography, geology and soils, ecology, and culture to allocate areas to a number of generic Landscape Character Types (LCT) which, in conjunction with informed judgement and interpretation are used to build the LCA. They are becoming increasingly GIS based applications and are being used to underpin various landscape management strategies and policies, informing a wide range of issues. Detailed regional LCA's have been brought together to form an overarching national typology, creating broad character areas, resulting in The Character of England Map (See CCN website and LCA Types and Areas Maps).
The HLC has also been compared to various LCAs across the UK with varying results (Dyson-Bruce et al 1999, Odell pers. comm., Wakelin pers. comm.) showing similarities in some areas, significant differences in others, although the reasons for this have not yet been fully researched.
Countryside Agency: Topic paper on LCA: http://www.naturalengland.org.uk/Images/lcatopicpaper5_tcm6-8176.pdf
They differ in philosophy and application in that HLA assess the landscape as to current and historic land use as well as historic character, whereas HLC assesses primarily historic character.
The East of England (EofE) HLC project, is the only application of HLC in England that uses a single but evolving methodology to ensure a consistency of application and analysis across a region (Dyson-Bruce 2002).
English Heritage commissioned a survey of HLC methodology in 2003 to develop a toolkit for future HLC applications in an attempt to harmonise HLC methodologies and to establish best practice across England. This resulted in 'Taking Stock of the Method' (Aldred and Fairclough 2003). The survey reviewed past methodologies into three major phases of development across England, and from these developed a series of proposals and established standards, as a toolkit for best pratice and future application. This document now informs the methodologies of all current HLC applications in England.
Cornwall HLC: http://www.cornwall.gov.uk/default.aspx?page=22352
In 2003 English Heritage undertook a detailed review of the various methodologies employed and have proposed an 'HLC Toolkit' to inform future HLC's. This aims to ensure that certain standards are met, and to facilitate a uniformity of approach across England.
The approach uses a range of single period types (current and relict) which reflect historic land use as well as character. This can result in complex maps showing palimpsests of multi-periods of discernable use within the landscape and consequently these types have been grouped into 14 broad categories, for ease of display for example Fields and Farming, Woodland and Forestry. These provide an over-arching framework, within which the specific types give the supporting detail. (Fairclough and Macinnes 2003)
Further information about Historic Landscapes in Wales can be found on the Cadw website at http://cadw.gov.wales/historicenvironment/protection/historiclandscapes/?lang=en
Natural Resources Wales have also worked on landscape assessment including that of the historic landscape, in conjunction with the Welsh Archaeological Trusts, as part of their extensive LANDMAP project. Further information about this can be found on their website at https://naturalresources.wales/planning-and-development/landmap/?lang=en.
In each county there are additional locally available datasets to inform and enhance the HLC, including Tithe and Enclosure maps from which an HLC may 'pick and mix'.
The outcome of these initiatives is the creation of a broad national audit of our historic resource at the landscape scale, based on common principles. It is an approach that complements and supports other historic data such as the HER, NRHE or NMR. HLC/HLAs can be applied at a range of scales from district to county to regional.
A wide variety of outputs can be created, not just custom coloured maps creating schematic or thematic maps at various scales, but also analysis and statistics, which in turn generate charts and graphs, based on the underlying databases of information supporting the GIS mapping of HLC. There is increased flexibility and interoperability of systems, not only between GIS software but with other standard PC software. This facilitates data exchange and use.
Consequently the HLC approach is under constant change and development in response to changes in thinking, political drivers and pressures, in parallel with improved GIS technology and data (see case studies below) in order to create a better application and also one for wider and specialised use.
In planning to create an integrated series of records to form a more complete HER one must consider the diverse nature of the various datasets, in detail, scale and quality. In any approach, where the data will be combined in some way, it will be essential to have national standards and guidelines to ensure a uniform approach and a compatibility of standards and the resulting datasets. This would have the added advantage of adding credibility to heritage asset management and records.
Such a nationally established HER and HLC protocol could extend the range and effectiveness of current methods of heritage management, contribute further to conservation, landscape management, development control work, research and so forth, and allow the heritage sector to operate on the same national basis as other regional or national bodies in areas such as, Regional Spatial Strategies (RSS), Strategic Environmental Assessments (SEA) and to help inform change indicators such as 'Countryside Quality Counts'.
The main approaches to combining HLC with HER datasets may be either as parallel or integrated datasets. Integrated, object oriented geo-databases would be a way forward, but would require good GIS skills to achieve this more advanced GIS data structure, with improved conformity in data quality and content, not least well defined and generally accepted spatial extents.
The data within the various HERs is variable in content, quality and structure, reflecting a wide variety of material from single finds to complex and extensive excavations, and development over a long period of time. On HER mapping sites are usually located by a six figure NGR and represented in GIS as an X-Y point – although there is an increasing thrust to convert these points to polygonal data, reflecting the sites true geographic coverage. Other digital data includes for example, the National Mapping Programme (NMP).
HLCs also differ in nature, quality and form with great variation between phases in the development of the methodology and their application across England. Recent projects have shown that the assimilation of different forms of HLC to create cross-border models can be achieved (for example Went et al 2003: Green and Kidd 2004: Chris Blandford Associates 2004).
Given that the data held within the HER record is complex and variable, often held in different data structures how is HLC best used or incorporated with such digital datasets?
To achieve some national strategy to gain conformity in data, a rationalisation, with defined data standards and structure may well be required to synthesise all these variable forms of data, both HLC and HER in themselves, prior to their being brought together in a single or series of linked databases into a fully integrated HER. This would enable full and consistent interoperability, application and analysis. The drawback is that, this may stymie future development and change, but on the other hand would ensure national conformity in data gathering, collation, analysis and management. However due to the diversity of dataset structure and content in the HLC and HER there may be no single solution.
Given the variability of HLCs, the integration of all HLCs into a nationally consistent dataset would require a rationalisation of the data, and data migration into new data structures with various levels of synthesis and interpretation of the extant data. A clear and well defined vision would be required to ensure conformity.
For an HER there would have to be some data cleansing or filtering process of duplicate, suspect and inconsistent data. In addition point data may need to polygonised, which introduces issues of where to place the boundary of sites. For example, Listed Buildings, which may have an unclear spatial definition – what part of the building, or series of buildings, how much of the grounds or curtilage are to be incorporated, that is, what is its 'footprint'? Similarly, Scheduled Monuments may have an defined edge that may well not conform to OS digital data. All these would require digitising as unique polygons, with all associated records.
One could cluster data together, such as finds scatters, crop marks or clusters of listed buildings with other historically significant buildings. This would require definition of a cluster – number, proximity, area and so forth, using consistent criteria, for example perhaps using a convex hull technique (whereby GIS 'lassos' a line, around a cluster of selected point data into a group which may then be represented as a polygon, possibly with an additional buffer zone). However the information would require additional interpretation by type, period, or a synthesis. Again they may well not conform to OS defined areas. These clusters or groupings of data could form various 'management layers', representing a new layer of generic or categorised information within the HER. This could perhaps be more easily understood and assimilated by other users that are non-archaeologists.
Whilst this process is being initiated and implemented, it would be opportune to fully consider future applications. With appropriate thought the data cleansing and manipulation could provide the answer to a wider variety of remits and end uses, that is a more useful streamlined management tool and resource.
One option is for a hierarchical system: the overarching broad HLC with the finer grained detailed HER, both possibly displaying at different scales. So as one zoomed in the HLC would fade as the HER records came into sharper focus. Hertfordshire County Council has used a series of nesting polygonal data for redefining the HER – which proved time consuming and thus may not be universally practicable (S Bryant pers. comm.).
exeGesIS SDM Ltd has developed an 'HLC Module' for the HBSMR system whereby, using a rules based, hierarchical system (see figure 53), of broad generic groups or categories (macro), with types, sub-types or attributes providing the detail (micro), with associated material, has enabled an integration of the HLC within the HER. It is an inter active system, the HER and HLC are embedded together into their spatial context. This approach has been piloted in Norfolk in its application of HLC.
Other issues are that of dissemination, training and use of such records within the wider community, costs or fees for use, training, web access and management. Who is going to provide the resource for the maintenance of these new more holistic, encompassing and integrated HERs?
It is advised to consult The Applications of HLC (in Clarke et al 2004), illustrated here, which describes in detail, the main uses to which HLC has been put to date – though it is thought there are many other potential applications yet to be identified.
The ranges of application vary from heritage, archaeological potential mapping, sensitivity mapping, conservation zones, landscape (LCA), farming, agri-environment schemes, minerals, coastal zone management, planning (strategy and policy), development control, research, local applications, parish surveys and public outreach. The list is constantly expanding with greater awareness of HLC and HER data and with greater experience.
HLC in conjunction with other historic data can support the Entry Level Schemes (ELS) and Higher Level Schemes (HLS) under Common Agricultural Policy, replacing the former Countryside Stewardship and ESAs schemes. The Land Management Information Service (LaMIS) illustrated here (figure 54) is one response to this issue. It supplies map-based information, including HER data, to assist farmers and other land mangers in devising appropriate ELS and HLS applications and in meeting their cross-compliance obligations.
The potential for modelling HLC has yet to be realised and here there is great promise awaiting development. Future modelling may well be dictated in response to various issues, of HLC in conjunction with other data – whether historic or from other sources, for example ecological, natural, census, sociological. A few ideas are noted below, to stimulate further work.
Similarly, the people who may use HLC in pursuit of their activities range far and wide in their backgrounds and levels of expertise and will no doubt expand as HLC data becomes more widely known and accepted.
HLC Landscape Types - to reflect
HLC based Landscape Themes – to reflect
HLC Modelled with Other Data
London-Stansted-Cambridge – M11 (Went et al 2003): The LSC- M11 work highlighted the problems in taking two radically different HER's (one monument based, the other event based) in adjacent counties and incorporating them into two county-based HLC's using the same methodology (see figure 55). The results confirmed that a certain screening or filtering of the HER data was required (which was unfortunately outwith the remit of the project, but is currently being progressed).
The project sought to provide a strategic approach of devising a 'sensitivity system' to the HLC data to facilitate strategic planning; the where, what and how. A scoring system was used, based on:
From these a generic model of low/low-moderate/moderate/high sensitivity scores were generated, which gave a range of 21 sensitivity zones (Figure 55). Associated with these are various advisory notes on criteria and capacity for and the zones correlated to current development proposals.
Milton Keynes South Midlands (Green and Kidd 2004): The MKSM work took a different approach, using comparative analysis of HLC and HER with other data to inform 15 'Historic Landscape Zones'. These zones were then used in defining criteria for location assessment for potential growth.
The Historic environment was assessed using
A rating of positive, neutral and negative (serious/moderate/minor) was then assigned to the data to suggest a potential spatial framework for the Milton Keynes Growth Area (see figure 56).
Thames-Gateway, (Blandford and Associates and EH, 2004): This study developed an integrated historic environment approach. Thames Gateway used the datasets to create three themes or heritage management layers:
The project separated the major forms of heritage data into comparable suites of information as they could not be incorporated satisfactorily into a single integrated suite of data. These three ranges of data were used to inform a final layer of 'Historic Environment Characterisation', with 140 character areas.
Balancing conflicting requirements during the creation of the Birmingham HLC: characterisation accuracy and detail vs. manageable polygon sizes and record numbers
Completed in December 2014, the historic landscape characterisation of Birmingham covers 26,798 ha (66,219 acres) and its database contains 6,974 HLC records, afterwards also combined into 111 broad character areas. 38 broad and 432 ‘individual’ HLC types are used to describe the Birmingham HLC records and – derived from them – another 18 and respectively 124 types for the character areas. Aiming to map, date and describe as accurately as possible the wide variety of past and present land use ‘realities’ encountered ‘on the ground’ – that is depicted in (or inferred from) the mainly cartographic sources used during the characterisation process - the Birmingham HLC used a number of approaches in order to achieve its intended characterisation accuracy while at the same time avoiding excessive fragmentation of the polygons drawn and/or an unworkable increase in the number of records captured.
1. Using ‘multi-polygon’ HLC records
Using this innovative approach, two or more polygons with (near-) identical land use ‘histories’ and typologies, and located relatively close to each other (though obviously not spatially contiguous), were attached to a single newly-created HLC record. As the GIS and HER software used to draw and record data (MapInfo and HBSMR) posed no problems in this respect, the ‘multi-polygon’ approach was implemented wherever deemed suitable, to the extent that the Birmingham HLC database now contains some 2,000 more polygons (c. 8,975) than actual records (6,974). This represents a significant reduction in the number of potential records contained in the Birmingham HLC database, without compromising the accuracy and detail of the characterisation itself. The size and nature of the (mainly) 1930s Kingstanding Estate in north-west Birmingham – one of the largest inter-war housing estates in the country – made it eminently suitable for the ‘multi-polygon’ HLC record approach, as illustrated by the 12 HLC records highlighted in this map. Also the estate is bisected by two dual-carriageway roads (‘polygonised’ as well by the Birmingham HLC) meeting in its centre, while the M6 motorway cuts across its south-western corner. The current HLC broad type of all the 12 records highlighted in the illustration is Residential, apart from one (HBM5816) which includes (almost) all of the retail facilities present on the estate and is made up of no fewer than 13 polygons (!) – four of them created purely as a result of the dual carriageway roads’ junction. As expected, the current ‘period of origin’ of most of these 12 HLC records is the 1930s, apart from three dated to the late 1940s and the 1950s. Drawing the HLC polygons also had to take into account the boundaries of the ancient Perry Barr Common (enclosed around 1815) which cut across of the modern estate. This resulted in 4 of the highlighted 12 ‘multi-polygon’ HLC records being purposely drawn so as to lie entirely within the area of the former commons.
2. Using ‘mixed’ HLC types
Where attempting to draw along the boundary between two different land use types, dates or both, would have resulted in unworkable polygon shapes (e.g. a patchwork of interspersed ‘mini-polygons’ belonging to only two records), the alternative chosen most often by the Birmingham HLC was to incorporate everything into just one polygon/record and then characterise it using a mixed HLC broad and ‘individual’ type (and/or also tweak its period of origin). In fact, more than a quarter of the 38 broad land use types employed by the Birmingham HLC are a ‘mixture’ of two (or more) existing types (originally inherited from the Black Country HLC); they combine for example Residential with Industrial or Commercial, Fields, Outdoor Recreational, Social/Public etc. While additional HLC broad and ‘individual’ types have to be created as a consequence, this ‘typological trade-off’ is more than compensated by the characterisation accuracy and dataset size benefits. The need to use ‘mixed’ types occurred throughout the Birmingham HLC particularly when characterising certain past land use realities, such as the combination of Victorian terraces and small works common in many parts of the city before the extensive post-war re-developments, or the combination of cottages, houses, smallholdings, alongside their closes and gardens, specific of the (semi-)dispersed settlement pattern of the pre-industrial era. Mixed HLC types were not exclusively used for describing past land realities though, as for example the Industrial and Commercial type was also used extensively to characterise current situations where traditional manufacturing had been replaced by industrial/trading/business/technology estates/parks. An example of the need to use mixed HLC types is characterising pre-modern Edgbaston – as illustrated by this map from 1718 – manor which lacked a ‘true’ village centre and consisted largely of houses, farms and cottages scattered in groups of two and three at best, including those in the vicinity of Edgbaston Hall and Church (HBM3780) – all record numbers mentioned here are highlighted in red on the map. In order to have any chance of ‘capturing’ at least part of this dispersed pattern, the resulting Birmingham HLC records had to either stay small (e.g. HBM3853 – 1.8 ha or HBM3875 – 1.44 ha), or use the ‘farm and enclosed fields’ mixed HLC type (e.g. HBM3852, HBM3869 or HBM3773, the latter farm located next to its Medieval moated predecessor – HBM3774). Incidentally, the closest thing to an Edgbaston ‘village centre’ in pre-modern times, was the small hamlet at Good Knaves End (top left corner), area covered by only two HLC records: a very small one (HBM3920 – 0.95 ha) and a larger one (HBM3871 – 2.71 ha), larger only because it also includes a small country house and its grounds.
We firmly believe that both methodological approaches described above worked well in practice during the characterisation process, and that together they helped keep the size of the Birmingham HLC dataset – and thus also the workload required to create it – manageable, without compromising the accuracy of drawing, dating and describing its records.
Countryside Character Network - for general information http://www.naturalengland.org.uk/ourwork/landscape/englands/character/lcn/default.aspx __CIS__ – Countryside Information System [http://www.cis-web.org.uk/home/
DEFRA – Department for Environment Food and Rural Affairs https://www.gov.uk/government/organisations/department-for-environment-food-rural-affairs
Sustainable Communities: http://www.historicengland.org.uk/images-books/publications/conservation-bulletin-47/
Historic Landscape Characterisation: http://www.historicengland.org.uk/research/current-research/discovery/landscapes-and-areas/characterisation/historic-landscape-character/
ELC – European Landscape Convention, Council of Europe, EEC http://conventions.coe.int/Treaty/en/Treaties/Html/176.htm
HS – Historic Scotland http://www.historic-scotland.gov.uk/ - for general information.
Land Management Information System LaMiS – an electronic Geographic Information System which enables farmers to develop appropriate land management, either for day to day management, long term planning agri-environment schemes or to formulate new plans for diversification. It is being piloted in Hampshire, North Yorkshire Moors and Sussex http://lamis.everysite.co.uk/lamis/.
MAGIC – MAGIC is the first web-based interactive map to bring together information on key environmental schemes and designations, in one place. MAGIC is a partnership project involving seven government organisations who have responsibilities for rural policy-making and management, and although it has been designed to meet the needs of the partner organisations, the facility is available to anyone over the Internet. http://www.magic.gov.uk/.
RCAHMS – Royal Commission on the Ancient and Historical Monuments of Scotland
RCAHMW - Royal Commission on the Ancient and Historical Monuments of Wales http://www.rcahmw.gov.uk/.
Obviously not all landuse types as defined in HLA can be made into archaeological sites. HLA on the whole provides a historical landscape setting in which the monuments lie, something that will be used in the contexts of strategic policy decisions in the future. For the purpose of examining how rare landscape types in HLA could be integrated into planning it was decided to use Designed Landscapes as the initial example.
As with all Local Authorities there is a separate inventory for Historic Gardens and Designed Landscapes. The Inventory for Aberdeenshire contains 26 examples of national importance, leaving a far greater number identified through HLA falling outside of the ‘special consideration’ given to those on the list. By taking such landscapes and giving them archaeological designations the following processes had to be undertaken:
The immediate benefit of SMR integration and removal of the HLA dataset from the DC process was that it removed the need for extensive training in interpretation and guidance for staff. The additional problem of why DC should consider HLA in the first place, when there are currently no policies that mention it, was also resolved, as the land-use types now became archaeological sites on the GIS overlays. Following this successfully adaptation of one part of HLA to suit the planning system, in particular development control, we can draw several conclusions:
By integrating the important landscape types from HLA into the SMR and packaging them with their own guidance notes and so forth, a very flexible system can be created that adapts to changing pressures from developers. It also makes the landscapes easier to understand for planning staff and could perhaps help form a detailed manual on HLA interpretation for the future in the Council. But perhaps the most important aspect is that the story HLA is telling is no longer being missed.