Landscape assessment is a sub-category of environmental impact assessment concerned with quality assessment of the landscape. Landscape quality is assessed either as part of a strategic planning process or in connection with a specific development which will affect the landscape. These methods are sub-divided into area-based assessments or proposal-driven assessments, respectively. The term 'landscape assessment' can be used to mean either visual assessment or character assessment. Since landscape assessments are intended to help with the conservation and enhancement of environmental goods, it is usually necessary to have a fully geographical landscape assessment as a stage in the process of EIA and landscape planning. During the initial phases of a project, such as site selection and design concept, the landscape architect begins to identify areas of opportunity or setbacks that may provide constraints. The architect prepares alternative options in order to compare their assessments and identifies the proposals which allow for the least adverse effects on the landscape or views. A landscape professional works with a design team to review potential effects as the team develops a sustainable proposal. Upon developing a design proposal, the landscape professional will identify and describe the landscape and visual effects that may occur and suggest mitigation measures to be taken in order to reduce negative effects and maximize benefits, if any.
This process, which operates within the larger framework of Environmental Impact Assessment, strives to ensure that any of the effects of change are taken into account in the decision-making process of a project. It is essential that any possible change or development to the landscape or views around a project be evaluated throughout the planning and design phase of a project. Thus, landscape assessment is sub-divided into two types: visual assessment and character assessment.
Visual assessment
This would look at how changes in the landscape could alter the nature and extent of visual effects and qualities relating to locations and proposals and how they affect specific individuals or groups of people. UK-related guidance on the preparation of these assessments is given in the 3rd edition of the Guidelines for Landscape and Visual Impact Assessment published by Routledge on behalf of the Landscape Institute & Institute of Environmental Management, 2013.
Character assessment
This includes assessments of each aspect of the landscape: geology, hydrology, soils, ecology, settlement patterns, cultural history, scenic characteristics, land use etc. It refers to the assessment of the individual components of a landscape listed above when experiencing change. It typically includes distinct descriptive and evaluative components. Guidance on the preparation of these assessments is given in Landscape Character assessment: Guidance for England and Scotland published by the Countryside Agency & Scottish Natural Heritage, April 2002.
Area-based assessment
This assessment can be completed at the regional scale as well as district, city, or catchment scale. This process is used to determine where landscape management is required. The process consists of three stages: landscape description, landscape characterization, and landscape evaluation.
Landscape description
The first step in completing an area-based assessment is to compile data in order to identify components of the landscape within a project area. Components of a landscape range from landform, geology, soil, vegetation cover, drainage patterns, built development, land uses, infrastructure, and heritage sites to cultural meaning. This step in the assessment of a landscape is not site specific, but instead, a general description of the landscape.
Landscape characterization
This step in the assessment refers to the process of identification, mapping, and description of landscape character areas. Landscape character areas are geographical areas made up by a combination of individual landscape components that make one area different from another area. The characterization of a landscape should begin to define the boundaries of the area being assessed.
Landscape evaluation
The last step in an area-based assessment is the evaluation process. This is a critical phase in the assessment process because landscape evaluation's are the driving force behind the planning and design of landscapes. Here, the assessment should identify important landscapes or natural features and assign rankings and priorities to features that require management.
Drawback
The evaluation process in the assessment is subjective and dependent on the professional completing the assessment and thus creates a controversial issue. Therefore, the assessment should always be completed by professionals who are trained to make accurate judgments of a landscape.
Proposal-driven assessment
Landscape quality can be assessed in connection with a specific development which will affect the landscape. Such assessment requires that a professional submit a development proposal. This approach to complete an assessment serves to identify the potential effects on landscape values brought forth by a certain proposal. The specific proposal is analyzed to evaluate the effects it may have on the landscape or character of the landscape, as well as the proposal's effect on the composition of available views. In a proposal-driven assessment, the area involved should include the site of the project as well as its immediate surroundings. This assessment should produce a detailed description of any physical changes to the landscape as well as a description and analysis of the effect these changes will have. This process should evaluate the importance of character, landscape, and visual amenity. Ultimately, this approach is effective if, and only when measures that can mitigate the effect of a given development proposal are identified.