In landscape planning and environmental impact assessment studies, evaluation of visual landscape character is often based on assessment of physical characteristics of landscapes (such as topography, land cover etc.) and is done by experts. On the other hand public or user preferences are generally neglected. This section aims to present and provide understanding of psychophysical and cognitive dimensions of visual landscape perception for landscape designers and planners.
Although we receive spatial information through many of our senses (seeing, hearing, smelling and feeling) sight is assumed to be the most valued sense. More than 80% of our sensory input is through sight (Porteous, 1996). Hence, most of the environmental perception, and likewise landscape assessment studies, focus on visual dimension of the perception process. Assessment of landscape character is fundamental to decision making process in landscape planning. Landscape assessment is a tool for determination of landscape quality and provides a systematic analysis and classification for sustainable management of landscapes. Within this context, the criteria for landscape perception studies are mostly scenic beauty or preference (Palmer, 2003).
Landscapes are aesthetic objects. There isn’t a universally accepted theory for landscape aesthetics. According to Maulan et al. (2006) neglect of scenic or preferred landscapes during development stage is one of the problems. Bourassa (1990) argues that landscape aesthetics is beyond the traditional theories of aesthetics. Based on Scruton’s approach, he states that people experience and respond to the whole scene, therefore "it is not relevant to speak of the aesthetics of individual objects in the landscape (e. g. buildings) without asking how those objects contribute to the wholes (landscapes) of which they are only parts”. For Bourassa (1988) there are two principles for landscape aesthetics, namely biological and cultural. The biological principle states that "aesthetic pleasure in landscape derives from the dialectic of refuge and prospect”. On the other hand, "aesthetic pleasure derives from a landscape that contributes to cultural identity and stability". As a product of either natural processes or human intervention, natural and cultural landscapes involve intrinsic (objective) and artistic (subjective) aesthetic values. Thus, theories of aesthetics may provide a basis for landscape scenic beauty assessments. Brief history of aesthetics in philosophical context is given below.