To address the project aim, we will conduct ecological assessments of structurally complex riparian zones along with soundscape recordings and participant surveys following a repeated measures design.
The Water of Leith is proposed as a case study bluespace to answer the research questions. It is a river that flows through Edinburgh, UK, cutting through a range of residential environments and consists of different riparian characteristics. Its structural complexity varies in terms of its vegetation, wildlife, water flow and riverbed materials, which all affect the acoustic environment. An initial rapid ecological assessment of sites along the Water of Leith will be conducted to determine potential suitable sites for investigation, using existing tools. A smaller number will then be assessed in detail to determine the four to six sites suitable for representing riparian structural complexity, ranging from complex, moderate, and sparse. At least one site for each complexity level will be chosen with two sites chosen for some or all levels to determine the value in different types of riparian structural complexity within a complexity level (RQ1). This helps determine the importance of the presence or absence of particular species. Site choice will also depend on attempting to control other variables that may influence the perceived acoustic environment. These will include, but are not limited to, the presence of anthroprogenic sounds (e.g. cars, construction), presence of people, visibility of the water, and visibility of urban environments.
In depth ecological assessments of the site to determine habitat structural complexity will involve recording height and diversity of different vegetation components, deciduous and coniferous trees (height of a representative subset of trees will be measured using a clinometer), shrubs, and herbaceous species. While conducting vegetation surveys, bird species seen and/or heard, along with other audible wildlife, will be noted. Assessments will be made at two different times of the day and in all four seasons to check the temporality of the habitat structural complexity.
Preliminary recordings of the acoustic environment using an audio recorder with an x/y microphone (for stereo sound) and a sound pressure level meter will be made to assist with site choice. To determine the acoustic environment in relation to the perceived acoustic environment (the soundscape), further recordings will be made at the time each participant is present. Standard acoustic and psychoacoustic metrics will be calculated from the recordings, along with sound source identification.
Soundscapes and wellbeing outcomes will be assessed using a questionnaire with open and closed questions. Data collection protocols for soundscapes will be followed (ISO12913-2). Wellbeing outcomes will involve assessing psychological restoration (after a pre-intervention stressor is given, such as a cognitive attention task), and affect (emotion). Measures will be taken pre and post intervention (exposure to the chosen sites). Participants will visit one site, complete a stressor task and answer pre-intervention questions, before sitting in the site for 5 minutes by themselves. Post-intervention questions including the wellbeing outcomes will then follow, while still stationary at the site. Participants will repeat this procedure in all study sites at the same time of day, with the order of site visits systematically varying across participants to control for order effects. This procedure will then be repeated at a different time of day and across all four seasons (RQ2 and RQ3).
There is further potential to simulate the sites using the audio recordings and ecological information to enable participant focused laboratory experiments whereby visual and acoustic characteristics from the riparian sites can be manipulated to check the role of a variable in the wellbeing outcomes.