Satellite Imagery and Its Influence on People’s Perceptions of Landscape
Creators: name: San Martin Saldias, Daisy
Publisher: name: RMIT University
Year: 2024
Subjects: classificationCode: 401301
subject: Cartography and digital mapping
classificationCode: 440699
subject: Human geography not elsewhere classified

description: The perception of a landscape involves the process of categorisation and differentiation of sensory information and individual experiences. Landscapes are modified and altered by natural and human processes and, therefore, are not static in nature, but vary in space and through time. Previous research has provided insights into how people perceive landscapes, and how these perceptions change in dynamic landscapes. Increasingly, digital globes such as Google Earth or Earth Explorer and mapping platforms such as Apple and Google Maps provide individuals with a view of the landscape from an unfamiliar perspective. Through these platforms, individuals may access visual information about their surrounding environment through satellite images, both of their own and of other landscapes from around the world. This way of looking at the landscape has the potential to shape how it is perceived and how its components are valued. To date, there has been little research that has focused on how this near-ubiquitous view of the landscape influences individual perceptions by the general community. This research project represents one of the first attempts to understand how satellite imagery can influence people’s perception and opinions of landscapes, which in turn can be used to inform landscape management decisions. 

The first research question examined the influence that viewing satellite imagery may have on the abundance of land use and land cover (LULC) classes, as determined by individuals, within familiar landscapes. To achieve this a survey of 52 participants from, Yungay, Chile, was used to explore the influence that interacting with satellite imagery had on people's perceptions of the abundance of land cover in the surrounding area. Participants, who were local to the area, were asked to quantify how much the landscape was covered by four land cover classes (agricultural, urban, plantation forestry, and native forest) and the distribution of cover. They were then provided with a tablet and instructed to explore satellite images of the Yungay area through Google Earth. The participants were then again asked to estimate the abundance of each class within the area. The results showed a significant difference in some participants' responses following the viewing of satellite imagery. In particular, participants significantly lowered their estimate of urban cover along with changes to how agriculture was distributed throughout the area after viewing satellite imagery. These results indicate that satellite imagery may influence how we perceive the makeup of a landscape.

Given the evidence that viewing satellite imagery can alter people's perceptions of their surroundings, the second research question investigated whether one cause of this change might be due to satellite images opening up a view of areas of the landscape that are not visible from key vantage points. The visible landscape is an important consideration in landscape management activities, shaping residents' perceptions of their overall environment and providing them with a sense of landscape connectedness, sustainability, and identity. Satellite imagery offers a different perspective, providing a complete 2D view of landscape composition. To make this comparison, Sentinel 2A imagery from a similar point in time to the survey data collection was classified into the primary land use classes in Yungay, Chile (with an overall accuracy of 83 \%). Viewshed analysis was then used to determine the proportion of the landscape visible from the road network under different scenarios (varied by distances from the road and road type). The abundance of each LULC class for that viewshed was then compared to the responses of survey participants without viewing satellite imagery. This process demonstrated that the visible Yungay landscape was composed of different abundances of LULC classes than the overall landscape. Furthermore, while there were some similarities between the visual landscape composition and participants' estimates of LULC cover, there were also important differences. In particular, participants failed to recognise that plantation forestry was the dominant cover in the area.

Whilst similarities were found between the current landscape and people's perceptions, the evolution of the landscape through their lived experience is likely to be a consideration in an individual's perception. The third research question developed a method for observing the visible landscape through time using open geospatial data. This method uses the Landsat satellite imagery archive (from 1986 to 2018) to represent changes that have occurred within the area. For four time points within the archive, a LULC map for Yungay was generated using machine learning (with $&gt; 82\%$ overall accuracy). The method then used a static digital surface model and dynamic road networks to determine the visibility of the Yungay landscape at each time point. While the native forests on the slopes of the mountains within the study area provide a natural backdrop, the flat topography of most of the area means that the foreground dominates the overall landscape view at each time point. While the road network (from 229 km in 1986 to 339 km in 2018) provided greater visible access to the landscape (an increase of 68 km2), a transition in the overall landscape composition from one dominated by agriculture to one dominated by plantation forestry was the dominant trend also seen in the visible landscape. This study highlights the role that geospatial data can play in understanding landscape perception, by developing a methodology using open-source satellite imagery to describe the visibility of LULC change from public road networks. 

To further understand the influence of satellite imagery of people's perceptions of the landscape, the fourth research question explored how people perceive the representation of landscape in satellite imagery, looking at both interpretation and appreciation of the image. In particular, the study aimed to investigate the relationship between an individual's ability to interpret the content of images from both the ground and satellite perspectives, their familiarity with the landscape, and their appreciation of land cover as seen from these two perspectives. This was achieved through a survey in which respondents were presented with images of land cover classes taken from eye-level and satellite imagery of the municipality of Yungay, Chile. Respondents were asked to interpret the primary LULC class from the images and to indicate their appreciation of the landscape as seen in the images. While similar overall accuracy was observed in the interpretation of satellite and ground-level imagery, differences in interpretation were observed between classes. For example, respondents showed a greater ability to distinguish between plantation and native forest from eye-level imagery, whereas the opposite was found for agriculture. It was also found that both familiarity and accuracy of interpretation affected the appreciation of the landscape being viewed. In particular, when respondents perceived the image to be dominated by a land cover that is more traditionally valued (i.e. native vegetation), they provided a higher rating, even when the image was of a different class (i.e. plantation forestry). These results suggest that while the ability to interpret satellite imagery is high, as it becomes more ubiquitous in our lives, its consideration in shaping perceptions and thus supporting land management activities is crucial.

Landscape perception is complex; it involves individuals processing information from a range of sources. The research presented in this thesis has demonstrated that satellite imagery is one of these sources and has the potential to shape our perception of the landscapes in which we live. It was also shown that our interaction with this imagery is complex and our ability to understand and interpret the information we see in the imagery plays a role in how it may shape our perception. Along with this it was shown that satellite imagery has a role to play in further our understanding of how perceptions are formed, through changes to the landscape and changes to how we access it. Satellite imagery therefore represents a new tool for use to in forming and understanding perceptions.