Using LANDMAP in Landscape and Visual Impact Assessments GN46
This guidance is technical and should be equally valid under any planning policy intentions in Wales, or development type, for example new housing developments, new roads, or any situation where the effects of a proposed change may result in significant effects on landscapes, views and visual amenity.
The Guidelines for Landscape and Visual Impact Assessment (GLVIA3), published by the Landscape Institute and the Institute of Environmental Management and Assessment in 2013, is the key resource for landscape professionals setting out the principles for LVIAs.
This guidance outlines our advice on how LANDMAP information should be used in LVIAs.
LANDMAP is a complete all-Wales GIS based landscape resource where landscape characteristics, qualities and influences on the landscape are recorded and evaluated into a nationally consistent data set.
LANDMAP offers a mapped, contextual baseline of landscape information about landscape character, qualities and values, in which the greater detail of a LVIA can be set.
LANDMAP comprises five spatially related datasets:
- Geological Landscape
- Landscape Habitats
- Visual & Sensory
- Historic Landscape
- Cultural Landscape Services
LANDMAP aspect areas define the character within each layer.
Planning Policy Wales (6.3.20) advocates the use of LANDMAP assessments to inform development management decisions, landscape character assessment, design and landscape sensitivity studies.
Using LANDMAP to identify search and study areas
The LVIA should identify the detailed study area that needs to be covered when assessing landscape and visual effects. This will usually be based on the extent of landscape aspect or character areas likely to be significantly affected, either directly or indirectly. It may also be based on the extent of area from which the development is visible, defined as the Zone of Theoretical Visibility (ZTV), or a combination of the two.
At the outset of the LVIA, it may not be clear exactly how large the study area needs to be. For some types of development such as wind farms, visual effects may spread across a very large area. In such cases, it can be helpful to use the already mapped and evaluated information in LANDMAP, as well as other sources such as landscape designations, existing landscape sensitivity assessments, inter-visibility maps or long-distance key views
in an early desk search stage to help to identify the extent of study area needed for the detailed LVIA. This search can be particularly useful in cases with large numbers of more distant visible landscapes to provide an evidenced basis for their inclusion or exclusion.
Search areas should also include the locations of other developments to be included in the Cumulative Landscape and Visual Impact Assessment (CLVIA).
The study area is where a full, detailed LVIA is completed. Significant landscape or visual effects on sensitive receptors are likely in this area. The study area may be asymmetrical, for example due to topography if part of the study area is concealed by higher landforms or is focused down a valley to a sensitive visual receptor at a greater distance.
Typical extent of search and study areas for tall structures
The type, form, scale, height and overall scale/spread of a development can have a large effect on the extent of likely significant visual effects.
While the extent of visual effects are specific to the development and the landscape in which it sits, for vertical structures such as wind turbines, chimneys and masts, we are able to provide the following distances as starting points for discussion with regulators and stakeholders on search and study areas. These distances are based upon development management cases and evidence reports in relation to vertical structures (NRW, 2016 and White et al 2019).
An approximate ratio between the maximum height of structure and distance to include in a search area is typically 1:150. This allows flexibility in defining the study area with a typical ratio of 1:100 for an average medium magnitude of effect, and 1:133 for an average low magnitude of effect on a high sensitivity receptor.
|Height structure (metres)||<25||26 to 49||50 to 79||80 to 108||109 to 145||146 to 175||176 to 225||226+|
|Search area (km)||
4 to 8
8 to 12
12 to 17
17 to 23
23 to 26
26 to 33
|Study area (km)||
2 to 5
5 to 8
8 to 11
11 to 20
20 to 24
26 to 28
Using LANDMAP at the search area stage of assessment
Filters are applied, as illustrated below, to existing LANDMAP evidence to help focus the detailed assessment of potentially sensitive landscape and visual receptors on the aspect areas most likely to be affected.
GLVIA3 box 5.1 (page 84) includes a wide range of criteria that can help in the identification of landscape value, recognising that high landscape value is not limited to designated landscapes.
LANDMAP includes quality assured evaluations that are informed by evaluation criteria specific to each dataset, each evaluation is justified in the survey record. Higher evaluations indicate higher landscape value with potentially greater landscape or visual sensitivity, depending on the nature and level of change from the development.
These nationally comparative aspect area evaluations can be mapped for the search area likely to be affected by the particular development proposal, in a rapid, desk-based early stage in LVIA.
As each development proposal will be different, no single method for using LANDMAP information can be prescribed. However, the following illustrates the approach.
Geological Landscape, Landscape Habitats and Cultural Landscape Services
Filter 1 Identify all LANDMAP aspect areas that overlap fully or partially or are adjacent to the development site boundary, these are most likely to undergo change.
Filter 2 Identify Geological Landscape aspect areas from filter 1 that record a special relationship with other aspect areas in the LANDMAP survey question 2. Include any extra aspect areas identified.
Filter 3 If a Zone of Theoretical Visibility (ZTV) map is available, retain all filtered aspect areas that are visible with the development.
Filter 4 Identify and retain filtered aspect areas that are evaluated as outstanding or high in
- Geological Landscape survey question 33 and/or rarity/uniqueness question 31
- Landscape Habitats survey question 45 and/or connectivity/cohesion question 42
Cultural Landscape Services does not include landscape evaluation information, retain all aspect areas identified from filter 1 or 3.
Complete detailed LVIA of final filtered LANDMAP aspect areas.
Visual & Sensory and Historic Landscape
Filter 1 Identify all LANDMAP aspect areas within the search area.
Filter 2 If a Zone of Theoretical Visibility (ZTV) map is available, retain all filtered aspect areas that are visible with the development up to the limit of the search area.
Filter 3 Identify and retain filtered aspect areas that are evaluated as outstanding or high in
- Visual & Sensory overall evaluation (survey question 50), and/or scenic quality (question 46) and/or character (question 48) if the overall evaluation is moderate
- Historic Landscape overall evaluation (survey question 40)
Filter 4 Retain all filter 3 aspect areas that are within the study area plus those aspect areas outside the study area but might contain highly sensitive visual receptors within the search area.
Complete detailed LVIA of final filtered LANDMAP aspect areas.
Using LANDMAP in the detailed LVIA study
Assessors carrying out LVIA need to judge the appropriate scale of reporting for the development, which may not always be the reporting scale of LANDMAP. For example, a housing proposal may need smaller reporting units whereas a wind farm may need larger ones.
We recommend that LANDMAP is used as the starting point for creating suitably scaled character-based reporting units. Reporting units may be LANDMAP visual and sensory aspect areas, where these are not entirely suitable, other LANDMAP aspect layers can be used to assist with the subdivision or amalgamation of visual and sensory aspect boundaries. Following good practice in landscape character assessment, further detail, refinement, updating and field work should be included when confirming reporting unit boundaries.
LANDMAP surveys provide a basic level of detail about the key characteristics, qualities and values of each aspect area. This will be insufficient for the needs of LVIA and further assessment with field work will be required. Good practice in landscape character assessment and in identifying key views and visual resources will be required to gain sufficient understanding at the right scales to make judgements of effects in LVIA.
Useful LANDMAP aspect area survey information includes the unique survey (UID) and name, summary of key receptors, characteristics, qualities, features and views, overall evaluation and identified evaluation questions including justification(s).
Information on management can be found in the recommendations, the Visual & Sensory recommendations also include key qualities and elements that should be conserved and enhanced.
While LANDMAP information can be cited, any LVIA conclusions must be explained and justified in landscape & visual terms. The information in LANDMAP informs the LVIA process, but does not, on its own, provide the conclusions.
For each LANDMAP dataset, you should also consider the geological landscape, landscape habitats, visual and sensory receptors, the historic landscape as well as cultural services.
Consider how existing landform may shape the visually experienced landscape. Consider how physical site modifications, such as re-grading, excavation and mounding, have significant effects on the landform and the way it is experienced. Likely significant effects may be higher where developments and associated infrastructure has a detrimental effect on the perceived scale and experience of the landform. Repositioning/siting may significantly reduce impact, minimise skyline visibility and any impact on landscape features such as rock exposures.
Consider how the contribution of habitats and land-use provides landscape diversity, connectivity, contrast and seasonal change and how these may be affected by the proposal. Likely significant effects may be higher where the development directly impacts upon these landscape characteristics within and close to the site boundary.
Visual & Sensory
Consider how likely sensitive receptors may be affected, including landscape characteristics, features, sense of place and qualities and sensitive visual receptors relating to key views and visual amenity.
Consider the historic landscape context and extent of influence of historic features and patterns. Consider key vistas and setting (where it is important to the significance of historic assets) that is most likely to be affected by the development. LANDMAP aspect areas that overlap with a Registered Historic Landscape can draw on additional detail from Historic Landscape Characterisations. Recognise the distinctions and the links between historic elements and features of landscape character, and their importance as cultural heritage in relevant chapters in an Environmental Impact Assessment (EIA).
Cultural Landscape Services
The Historic Environment Record classes (question 28) and in time the folklore, artistic and events questions 17-21 may indicate notable or highly valued cultural associations for the area. Consider how the development affects the perceptions and values of these cultural associations and how they are experienced.
In addition to LANDMAP, there may be other contextual baseline sources available to inform the LVIA, for example:
- national and local landscape character assessments
- seascape and marine character assessments
- Registered Historic Landscapes and historic landscape characterisations
- special landscape areas
- siting and design guides
- landscape sensitivity assessments
- special qualities and management guidelines identified in National Park and Area of Outstanding Natural Beauty management plans
- World Heritage Site management plans
- Conservation Area appraisal and management plans
Making judgements about effects and their significance
LVIA should be iterative with the siting and design process. LANDMAP survey information and other baseline sources and planning guidance will provide context.
LANDMAP does not provide a specific judgement about the effects of a specific development proposal. Evidence based, reasoned judgements, with reference to the landscape and visual effects must be made, following good practice as set out in GLVIA3.
As LANDMAP evaluations are specific to each aspect area and the unique perspective of each dataset, a study area is likely to have a mix of evaluations. Do not add different evaluations together to create a single landscape value. It is more helpful to recognise what is distinctively important about a landscape (key characteristics, qualities and values) and assess how this would be affected by the proposed development, to what degree, and therefore what the significant effects would be.
Aspect areas with a high or outstanding visual and sensory evaluation may be more sensitive to change from development. Historic landscapes evaluated as high or outstanding are likely to have little to no modern day development influences. Understanding this baseline and identifying the location of key public viewpoints as visual receptors is essential to avoiding sensitive areas at the strategic planning stage when considering site options and alternatives.
How to access LANDMAP datasets
Accessing LANDMAP Data (2020) provides step by step guidance on accessing LANDMAP datasets and is available upon request.
Tel. 0300 065 3000