Visibility analysis in urban spaces: a raster-based approach and case studies

Abstract

In this paper a method for the estimation of the visual impact of buildings with symbolic relevance, such as skyscrapers that are out of scale with their surrounding urban space, is discussed and applied. It is based on the viewshed analysis as developed in rural landscape studies, but it also takes into account the peculiarity emerging from the urban studies. In order to go beyond the sole information of whether a cell is, or is not, visible, which is typical of viewshed analyses, in this work the various factors that cause the visual attenuation with the distance are discussed and quantitatively assessed by determining various limit-of-visibility distances that may also be time variable. These factors are the visual acuity, the contrast between the target and its surroundings, the atmospheric visibility, and the recognition process of the subject. An application of this methodology is carried out on various case study buildings in the city of Turin, Italy (an ancient building, an urban landmark, the Mole, and a skyscraper under construction). From the visibility maps, under various conditions, it can be seen that the new skyscraper will be a major landmark not only for the entire city, but also for the surrounding municipalities.

Peyzaj Tasarim Süreçleri̇nde Coğrafi̇ Bi̇lgi̇ Si̇stemleri̇ni̇n Kullanimi: Eski̇şehi̇r Şehri̇ Derya Parki İçi̇n en Kisa Yollarin Ve Seyi̇r Terasi Konumlarinin Beli̇rlenmesi̇

“…Görülebilirlik analizi, gözlem kulesi (orman yangınları vb.) için en uygun yerin belirlenmesi, telekomünikasyon kuleleri ve radar anteni için uygun yerlerin seçilmesi, milli parklarda doğal patika güzergâhlarının planlaması, su yüzeylerinin (okyanus, göl deniz gibi) görülebilirliğinin insan sağlığına etkilerinin değerlendirilmesi [29], orman alanlarının manzara değeri ve işlevinin arttırılması [30], dış ortamlardaki kablosuz networklerde uygun sinyal dağılımının planlanması, rüzgâr türbinlerinin yer tespiti [31], kentteki çeşitli tarihi binaların görünürlüğünün analizi [32,33] gibi konularda arazi bazlı mekânsal modelleme çalışmalarında kullanılmaktadır.…”

Extracting Information from an Urban Network by Combining a Visibility Index and a City Data Set

“…This is just of the reasons why it may be quite relevant for urban designers and researchers to analyse the visibility of urban spaces [7,8]. Visibility analysis has been proved to be useful in investigating urban environments in general, allowing researchers to form mathematical descriptions of systems which complements other phenomenological approaches, hence enabling us to predict the inhabitant experiences in urban environments with reasonable certainty [9,10]. In visibility analysis, it is important to have metrics that characterize different aspects of the visibility relationships.…”

Visibility and perception analysis of city monuments: The case of Bratislava city centre (Slovakia)

“…A DLM uses numerous geometric attributes and indicators to describe the visual properties of the landscape or city (e.g. Ode et al, 2008;Roos-Klein Lankhorst et al, 2011;Van Lammeren, 2011;Garnero and Fabrizio, 2015;Fisher-Gewirtzman, 2016;Lin et al, 2017). To analyse the geometry-related spatial characteristics of visible urban environments, we defined a set of all points visible from a given point in space.…”

“…The rapid growth of urban tourism has led to an increasing demand to develop measures that cope better with a large number of visitors (Bauder and Freytag, 2015). Convenient sightseeing in cities can be oriented to selected monuments and landmarks or to objects related to urban tourism (Ashworth and Page, 2011;Edwards et al, 2008;Garnero and Fabrizio, 2015). Thus, the planning of sightseeing in a city raises the question of how to find a convenient sightseeing route and the best places for seeing the monuments (Di Lorenzo et al, 2012).…”

“…The physical state of a city as a primary object of visual perception can be assessed by objective criteria -in architecture (Benedikt, 1979;R�d and van der Meer, 2009) or in city planning (Batty, 2001), for example -to find the best places (points) to view selected monuments. An objective approach takes into account general, conventional knowledge of visual perception (Granö, 1929;Bell, 1999;Daniel, 2001;Sevenant and Antrop, 2007), using the conceptual foundations and synergetic tools of Geographic Information Systems (GIS) to analyse visibility and the visual qualities of a city (Nijhuis et al, 2011a;Van Lammeren, 2011;Garnero and Fabrizio, 2015;Fisher-Gewirtzman, 2016;Lin et al, 2017).…”