Visual Impact Assessment Research Articles

The contribution of a GIS-based landscape assessment model to a scientifically rigorous approach to visual impact assessment

Visual impact assessments (VIAs) rely primarily on key observation points (KOP). However, the analysis is highly dependent on the selected viewpoints. An analysis using a GIS-based landscape assessment model (LAM) would be an informative complement to a KOP analysis by providing results that cover the complete study area.A LAM based on intrinsic landscape attributes is presented that includes four components: visual quality, visibility, visual magnitude and visual impact. The model is applied to two proposed alternatives for the Northern Pass, a 300 km long 345 kV transmission line in New Hampshire, USA, and an existing transmission line in the shared corridor. The validity of the four model components is tested against field observations and the evaluation of photographic simulations. Correlations are generally above 0.50, indicating high validity (Cohen, 1988). A new metric is introduced that combines the mean value with the size of the viewshed.Effect size (Cohen’s d) is used to evaluate the cumulative and incremental visual impacts within three geographical sections, the White Mountain National Forest—a nationally recognized scenic resource—and the project as a whole. In general, the results indicate that the visual impact of the existing transmission line is large, and while the incremental impact of the proposed alternatives are smaller than the existing impact, they are sufficient to indicate that the cumulative impact is unreasonable.The final discussion considers the difficulties in determining when an impact is unreasonable, and how the LAM might be extended by including viewer sensitivity and scenic resource concern.

Accuracy of wind farm visualisations: The effect of focal length on perceived accuracy

Wind energy has been the fastest growing renewable energy technology for more than a decade. However, the visual impacts of wind farms are still one of the most controversial effects of wind energy development. Photomontage visualisations are frequently used in Visual Impact Assessments22List of abbreviations used in this article:VIA – Visual Impact Assessment (VIA) to give a sense of scale of the proposed development. Yet visualisations in VIAs are often perceived to underestimate the scale and magnitude of the visual impact of wind turbines. The aim of this multiphase mixed methods study is to explore the perceived accuracy of images that represent the visual impacts of both onshore and offshore wind farms. Field visits and data from a public survey are used to assess the accuracy of visualisations and to examine the effect of camera lens focal length on perception of scale of wind turbines. Results show that panoramic photomontages are perceived as the least accurate, while images taken at 75 mm focal length in full frame format are perceived as the most accurate form of representation of the scale and visual impact of wind turbines. These findings imply that the panoramic visualisation technique, which has been used for decades to predict the scale of wind turbines in VIAs, is ineffective in predicting accurately the visual impact of wind farms, and an alternative predictive technique is needed. For wind farm visualisations the use of 75 mm full frame image format is recommended in order to improve the accuracy, enable better informed decision making and avoid the loss of credibility of visualisations and VIAs.

The implications for visual simulation and analysis of temporal variation in the visibility of wind turbines

The visual impact of wind turbines is a central issue in their public acceptance. New wind farm proposals are commonly subject to visual simulation and visual impact assessment. Guidelines for both these processes are already used in a number of jurisdictions and there is widespread interest in making simulation and impact assessments as meaningful as possible. To a large degree the guidelines for both processes tend to be based on worst-case (full-frontal) conditions. There are two quite good reasons for this. Firstly, the worst-case sets a boundary for visual impact. Secondly, we seldom know enough about how visibility or visual impact changes over time and what ‘typical’ conditions are like – or how the range of conditions is distributed. This paper argues that if we can address this knowledge gap, then we may also be able to take a more nuanced approach to simulation and analysis. It should be possible, using widespread atmospheric visibility data, to determine the temporal distribution of visual impacts at a particular location rather computing a single estimate. It may also be valid to create simulations of both worst-case and more typical conditions. This paper explores the key variables affecting visual impacts – visual magnitude and color difference – and how they may be monitored and analyzed efficiently and effectively. A wind farm in southern Victoria, Australia is used as the case study. Recommendations are made on how the approaches could be used more widely.

The contribution of key observation point evaluation to a scientifically rigorous approach to visual impact assessment

This study introduces scientifically rigorous methods to visual impact assessment. Images of the existing condition are edited to simulate two alternatives at 22 key observation points (KOPs) along a proposed transmission line. Scenic value and visual contrast are assessed from the images by six independent evaluators. Photo validity and rating reliability are evaluated, and found acceptable. Procedures to measure cumulative and incremental visual impacts in a view are demonstrated. Both mean ratings and effect size are used to interpret the severity of visual impacts. The cumulative impact measured by contrast ratings is unreasonably adverse at many KOPs. The incremental visual impact measured by contrast ratings is less severe than the existing transmission line’s visual impact, but still unreasonable at many KOPs. The incremental impact determined by the change in scenic value is less severe than indicated by visual contrast, but still identifies many unreasonable impacts. Burial of 84 km of the transmission line results in an improvement at the affected KOPs but unreasonable impacts remain at other locations. The exigencies of professional practice limit the number of evaluators—however, scientific rigor requires a greater number of evaluators to establish mean ratings with reasonable levels of confidence. It is proposed that this may be an opportunity to involve the public. This is the first-time effect size has been used to interpret contrast ratings, and additional reports on its effectiveness are needed. It is hoped that professionals conducting visual impact assessments will employ these procedures and report them publicly.

Wind farm repowering guided by visual impact criteria

Within a repowering context, this paper opens a new field of application for visibility and Visual Impact Assessment (VIA) procedures in the decision-making process typical of the design stage of Wind Farms (WF). The proposed methodology presents a test capable of reporting on the visual sustainability of different layouts. It is called Equivalent Visual Impact (EVI). To work with EVI, visibility data have to be numerically available at a level of each pixel and each Wind Turbine (WT). This is called High Resolution Data (HRD). The paper shows how these ideas, EVI and HRD, were applied to a real repowering experience; the result was that the WF could sustain an increment in its power by 37.25% with no additional visual effects. Other associated consequences are discussed.

경관인식에 따른 산지경관 관리 가치 연구†

Recently, the conservation of mountainous landscape and compensation for diverse demands for mountain areas such as leisure, recreation and welfare are under discussion. The purpose of this study is to investigation the perception of mountainous landscapes by those who view and recognize the landscapes and to estimate economic value by estimating the willingness to pay for the management of mountainous landscapes. This study will provide data for the management of mountainous landscapes. As a result of comparing the perception between the territorial landscape and the mountain landscape, the mountain scenery was 3.96, the management level satisfaction was 3.28, and the management necessity was 4.38, which was higher than the national landscape, while the national landscape was satisfactory but the management level was insufficient. Jeju Island (39.0%) and Gangwon (38.6%) were chosen as the most scenic areas with beautiful forest and mountainous landscape resources. The aesthetic characteristics of the vast skyline of mountain scenery, the background of the area, and the mountainous landscape that forms the landmark were evaluated highly. And, it is considered that consciousness of mountainous landscape management is heightened by 86.8% of respondents, who positively answered the Mountainous Landscape Visual Impact Assessment before the development project. The per capita payment amount for mountainous landscape management was calculated to be 3,742 won and, based on the number of visitors to the mountain National Parks in 2016, it is estimated to have an economic value of about 169.5 billion won. Policymakers have limitations in the mountainous landscape management policies of the administrative subject. Establishing a consensus on the importance and necessity of landscape management by diagnosing the status of public perception is expected to help create more effective policy direction and implement strategies for the management of these areas.

Attitudes Towards Changes in Landscape from Chao Phraya Riverfront Extension Project: Community and Commercial Areas

This research studies public attitudes towards changes in the landscape from Chao Phraya riverfront extension project in urban areas, especially in residential communities and commercial areas in order to propose the guidelines for mitigation of the public attitudes in regard to the changes in the landscape along the river. The research framework is applied from the Visual Impact Assessment. The research may be described in six parts. They are: 1) Reviewing and surveying the study areas, selecting representative sites, 2) Define variables of the research, 3) Define population sampling, 4) Designing photo – questionnaires as photomontage technique was applied on selected pictures to depict the appearance of 4 mock-up riverfront extension areas on the front of 3 representative sites and collect data 105 sets, 5) Data analysis using the statistical tools, 6) Summarizing results and formulating guidelines for appropriate developments. The findings indicates that the extension areas along the Chao Phraya River in the residential communities and commercial areas affects public attitudes in different ways. The positive attitudes towards the changes have decreased in the areas where present conditions are already in good condition and look attractive. However, the negative attitudes have decreased in the areas where current conditions are deteriorated. Therefore, the extension areas may not be only the element affecting public attitudes toward changes. The study result reveals that significant elements which affect the attitudes towards changes in negative ways for all the representative sites are the oversized width of the extension areas along the river.

Using participatory GIS to examine social perception towards proposed wind energy landscapes

Thirteen onshore wind farm projects, totalling approximately 700 wind turbines, are proposed for the West Coast Region (WCR) of the Western Cape Province in South Africa. Wind energy exploitation possesses the ability to transform what can be classified as natural landscapes into landscapes of power, making the type of landscape on which wind turbines are deployed a prominent factor in its social acceptance or rejection. This paper examines the landscape aesthetics and land use interference of proposed wind farms in the WCR of South Africa through determining if social acceptance or rejection of proposed wind farms is dependent on the residents and visitors scenic and land use valuation of the natural landscape. The results indicate that the visual intrusion of wind turbines is the impact that respondents are least concerned with contrasting with the findings of international literature and further reasons for this anomaly are interrogated against the background of South Africa’s dire electricity needs. The paper concludes that visual impact assessments alone are not sufficient for evaluating landscapes and this paper recommends that participatory geographic information systems (PGIS) be used in addition to existing wind energy landscape assessments.

Exploring the perceived intrusion of mining into the landscape using the fuzzy cognitive mapping approach

Fuzzy Cognitive Mapping (FCM) is a popular method used towards studying the structure and behaviour of complex systems in a wide range of applications. This paper presents the first application of FCM in exploring factors affecting the perceived nuisance caused by the impact of mining projects on the landscape. To this end, a team of experts in mining and landscape engineering was recruited to develop the conceptual model of the “mining-landscape-society” system. The individual Fuzzy Cognitive Maps (FCMs) were not significantly different among the experts, as regards the graph theory indices, and the most central concepts reported were related to the socioeconomic profile of the surrounding area, the characteristics of the mining project, and the characteristics of the landscape. The construction and analysis of the collective FCM offered further insights into the understanding of the system and allowed the analysis of its concepts by means of dynamic model inference. The FCM framework proved to be helpful in identifying and quantifying the factors interacting in the “mining-landscape-society” system and offered the ability to study the role and significance of central concepts in the overall system behaviour. In this sense, it is claimed that FCMs could significantly improve the domain of visual impact assessment related to mining activity. Nevertheless, much work remains to be done in order to improve the model and produce more reliable maps. Future efforts should be built on larger groups of experts from different disciplines as well as on non-experts who influence environmental decision-making.

Wind farms and landscape visual overload

The process of wind turbine allocation which has already started in Croatia is currently based on the legislative regulatory system that lacks a basic national strategy plan for the integration of wind turbines into landscape. The result of this kind of ‘case to case’ approach to development is the uncertainty regarding the potential consequences of these actions on landscape. One of the possible consequences of interpolating a greater number of wind turbines in a rural landscape is its complete visual transformation into a landscape of technical character and, as a result, the loss of its former natural and cultural values. Rural coastal areas are potentially the most affected due to their great potential for the development of wind turbines. The main dilemma in this paper is the issue of a potential visual overload of sensitive rural areas in Croatia. Thus, a projection of visual exposure of all the existing and planned wind farms was made for this purpose. Such projection could be useful for any future cumulative visual impact assessment of wind turbines on the existing landscape, as well as for the development of an appropriate strategy plan for wind power exploitation.

Assessment of the aesthetic landscape properties for managing areas of outstanding natural beauty and historical significance

The restoration of historical cultural landscapes, which has become increasingly widespread in developed countries, has resurrected two common approaches based on a specific set of measures applied for landscape reconstruction and preservation (area management plans) and landscape and visual impact assessment (so-called LVIA). The development of area management plans is associated with the evolving concept of a target state, in which the landscape preserves its functionality and possesses the properties of a historical reference model. Such properties are sought using geographic information systems and old map sources, in the course of reconstruction of landscape history. The implementation of LVIA requires prior structural modeling of a visual space in relation to its observers, photographs, and the revealing roles of individual components in forming landscape scenes, as well as determination of visual deformations that negatively affect the aesthetic properties of the landscape. Adverse aesthetic changes may occur as a result of both new actions in development of the area and the natural dynamics of the landscape and its “wilding” (ecorehabilitation). The design of a three-dimensional cultural landscape computer model, supplemented by step by step parameterization of potential changes, makes it possible to objectify the entire process of evaluating acceptable impact on the aesthetic properties of a landscape and to apply this model for solving conflict issues associated with the development of areas of outstanding natural beauty and historical significance.

The application of GIS and 3D graphic software to visual impact assessment of wind turbines

Visibility of wind turbines is one of the most subjective factors influencing the decision on the potential location to build wind turbines. The spatial extent of the visual impact of wind turbines usually covers a wide area. The paper proposes a new method for visual impact assessment of wind turbines. The proposed method uses GIS tools and 3D graphic software for developing three-dimensional models and computer animations. The developed method was verified in the field. The usefulness of this method is presented on the example of the Poznań Metropolis in Poland, where construction of wind turbines is considered. The analyzes related to visual assessment of the effect of wind turbines with a height of 150 m above ground should be performed over a distance reduced to 12 km. Visibility range of wind turbines depends on the position of the observer in relation to the wind turbine. For longitudinal, diagonal and frontal views the visual impact is limited to 4, 10 and 12 km, respectively.The results obtained using the method proposed were compared with those provided by the other methods used to assess the visibility of wind turbines. As a conclusion, the advantages of this method in favor of its popularization were described.

Effect of traffic noise on perceived visual impact of motorway traffic

Visual impact is one of the major environmental impacts of motorways and requires adequate assessment. This study investigated the effect of traffic noise on the perceived visual impact of motorway traffic by comparing impact with sound to impact without sound. Computer visualisation and edited audio recordings were used to simulate different traffic and landscape scenarios, varying in four traffic conditions, two types of landscape, and three viewing distances. Subjective visual judgments on the simulated scenes with and without sound were obtained in a laboratory experiment. The results show that motorway traffic induced significant visual impact. In both sound conditions, increases in traffic volume led to higher visual impact and changes in traffic composition changed the impact significantly when traffic flow was low. Visual impact was significantly higher in the natural landscape and the increment was largely constant and independent from the effect of traffic condition in both sound conditions. The effect of viewing distance was also significant and there was a rapid-to-gentle decrease of visual impact by distance both with and without sound, but the decrease with sound was less rapid and the decrease pattern less clear. Overall, introduction of traffic noise increased the visual impact by a largely constant level which did not show clear dependence with noise level, traffic condition, landscape type, or viewing distance, although there was a possible effect of viewing distance on the increase. It suggests that the additional impact caused by traffic noise should be considered in visual impact assessment of motorway projects.

The impact of wind farm visibility on property values: A spatial difference-in-differences analysis

Today's investment decisions in large-scale onshore wind projects in Germany are no longer determined only by the investment's economic benefit, but also by concerns associated to social acceptance. Despite a mostly positive attitude towards the expansion of wind power, local public concerns often stem from the belief that the proximity to large-scale wind farms may lead to a decrease in property prices. In particular, the change in landscape caused by the construction of a wind farm may have an adverse impact on the view from some properties, and thus may negatively affect their price. To investigate the potential devaluation of properties in Germany due to wind farms, we use a quasi-experimental technique and apply a spatial difference-in-differences approach to various wind farm sites in the federal state of North Rhine-Westphalia. We adopt a quantitative visual impact assessment approach to account for the adverse environmental effects caused by the wind turbines. To properly account for spatial dependence and unobserved variables biases, we apply augmented spatial econometric models. The estimates indicate that the asking price for properties whose view was strongly affected by the construction of wind turbines decreased by about 9–14%. In contrast, properties with a minor or marginal view on the wind turbines experienced no devaluation.

Methodology of Visual Pollution Assessment for Natural Landscapes

In 2014 the Ministry of Environment of the Republic of Lithuania initiated creation of Methodology of the Assessment of Visual Pollution to Natural Landscape Complexes and Objetcs. In order to prepare the Methodology legal (international and national level) and theoretical framework (world-wide and Lithuanian experience in the field of visual impact assessment (VIA) and assessment of landscape visual-aethetic potential) was analysed and evaluated. Using the method of logical analogy and considering the results of analysis of legal and theoretical framework of VIA, and peculiarities of Lithuanian landscape, the concept of visual pollution and the main methodological stages of visual pollution assessment (VPA) for natural landscapes were proposed. The authors of the methodology state that the assessment of visual pollution should be based on: the establishment of the overall landscape character, visual character, visual capacity, and other aspects as the starting point for the evaluation of visual pollution; assessment of visibility of a pollution object; description of physical, visual and other characteristics of the pollution object; evaluation of negative visual impact (visual pollution) according the level of contrast of physical, visual and other characteristics of landscape and the pollution object. DOI: http://dx.doi.org/10.5755/j01.sace.13.4.13820

Comparing saliency maps and eye-tracking focus maps: The potential use in visual impact assessment based on landscape photographs

In this study, we analyse how well saliency maps, which are theoretical predictions of the human viewing pattern, are correlated with human focus maps, obtained by tracking 42 observer's eyes while free-viewing landscape photographs ranging from rural to urban environments. The Pearson's correlation coefficient was calculated on the predicted and measured pixels’ greyscale values. A relatively high correlation was obtained, indicating that the saliency maps can be used as reliable predictions of the human observation pattern and thus can predict which elements in a landscape will catch the attention. These findings are useful in visual impact assessment, a step in the planning process which is often not well elaborated or even skipped. Saliency maps could, for instance, be used to compare the conspicuity of different designs of a construction when simulated in photographs of the original landscape. As the visual impact of an object is reduced when its visual perception decreases, the least salient design will also have the lowest visual impact and will correspond to the best integration into the existing landscape. This method is easy and produces an objective measure of the degree of visual impact. However, as slight differences in correlation depending on the degree of urbanisation of the landscape were found, this methodology will not be equally reliable in all types of landscapes. Predictions of the viewing pattern in rural landscapes with a limited amount of buildings have been demonstrated to be most reliable. In more urbanised landscapes this reliability slightly decreases but nevertheless remains significant.

Visual Impact Assessment: Where Have We Come from and Where Are We Going?

This paper is a historical overview of the development of visual impact assessment (VIA) methodology as implemented by US Federal agencies from the 1960s until the current time. VIA methods are to be used as part of environmental impact assessment for projects which could have significant impact on landscape aesthetics. Also included are methodological challenges with current large-scale renewable energy development in the US and Europe.

Visual Impact Assessment of Free Standing Billboards in the Road Landscape near Elektrėnai (Lithuania)

Abstract Free standing billboards (FSBs) have a significant negative visual impact on landscape. In majority of foreign countries the construction of FSBs is regulated by various legal instruments, guidelines, and control manuals. In Lithuania the construction of FSBs considering visual impact is poorly regulated by juridical and spatial planning means. Considering this situation methodological guidelines for regulation of FSB construction taking into account their visual impact were created. The guidelines are a part of the Landscape Guidelines for the Roads and Railways of National Significance [10] which is a manual set to fulfil the requirements of the European Landscape Convention [4] to broaden the knowledge on this subject and to integrate landscape issues into all matters that influence the state and the future of landscape. The aim of the article is to show the possibilities of application of the guidelines by performing visual impact assessment of FSBs in the road landscape near the town of Elektrėnai on one of the main highways of Lithuania: A1 Vilnius-Kaunas-Klaipėda. The proposed stages of FSB visual impact assessment are the following: analysis of landscape spatial structure designating visual spaces perceived from separate road sections; analysis of FSB layout possibilities designating visual spaces protected from FSB construction and visual spaces as FSB construction areas; establishment of possible visual contrast level of FSB, and establishment of FSB location in visual space and visual contrast character according to the Identity Index context (Similarity, Identity, Difference Index) theory and results of evaluation of aesthetic potential of the visual space. In the performed research we used the possibilities of spatial data management and analysis of geographic information systems (GIS) and basically implemented the first three stages of FSB visual impact assessment. The fourth stage was not implemented because it deals mainly with technical issues of FSBs. We tried to solve questions that are most important on the level of spatial planning when developing special plans for FSB construction.

Assessing cumulative visual impacts in coastal areas of the Baltic Sea

Anthropogenic activity such as offshore wind energy farm development, shipping activity, resource extraction platforms or marine aquaculture can have adverse impacts on the visual quality of coastal landscapes. GIS-based viewshed analysis is the most widely used technique to address visual impacts. However, despite the wide application its spatial extent remains limited to local and regional studies. This study presents a GIS-based model for cumulative visual impact assessment on macro-regional scale based on a case study for the Baltic Sea. The viewshed model was deployed over a visibility zone covering 54% (223.641 km2) of the Baltic Sea space using a database of 63,672 observation points integrated by geospatial data on existing and planned sea uses representing potential visual stressors. Results show that areas of highest potential visual impact are sheltered coastal areas with complex geomorphological features such as barrier islands, peninsulas, straits, archipelagos and lagoons in combination with intensive anthropogenic activity and presence of nature protected areas. The methodology can be applied to any coastal area of the world to classify coastal areas due to their cumulative viewshed characteristics and as early monitoring tool for visual impact assessment on transboundary scale.

Analysis of Legal and Theoretical Framework Creating the Methodology of Visual Pollution Assessment for Natural Landscapes

Fulfilling the requirements of European Landscape Convention and following the statements of the National Landscape Policy of the Republic of Lithuania in 2014 the Ministry of Environment of the Republic of Lithuania intitiated the creation of Methodology of the Assessment of Visual Pollution to Natural Landscape Complexes and Objects. In order to prepare the Methodology legal and theoretical framework of visual impact assessment (VIA) was analyzed and evaluated. Summarizing the analysis of the legal framework it can be said that national legislation requires the avoidance of visual pollution, but there are no recommendations how to evaluate visual impact. Foreign countries in the field of VIA, unlike Lithuania, have validated concepts of landscape visual quality and planned activity or object visual impact assessment; methodological recommendations of VIA, based as much as possible on principles of objectivity and systematicity, which are used in practical activities of planning and design. Methodologies used by Lithuanian authors are well developed theoretically and intended for the overall evaluation of landscape visual quality or VIA, designation of landscape visual quality classes, evaluation of visual spaces (VS) indicators, establishment of VS visual resistance and sensitivity. Parts of some works can be used for creation of methodology of visual pollution (negative visual impact) assessment.DOI: http://dx.doi.org/10.5755/j01.sace.12.3.13022