Evaluation of unpleasant green environment based on biological reaction and contingent valuation

Abstract

Green environment such as parks and woods have been maintained as having healing and relaxing effects. These effects have been evaluated by biological reactions and contingent valuation method. Most previous studies are focusing on green environments where maintenance is done. On the other hand, there are many unmaintained green environments such as abandoned detached houses and woods. There is a possibility that people feel uncomfortable with these problems, such as increasing anxiety about crime prevention and disasters and deteriorating the local image. However, to the best of our knowledge, no research has been conducted that focuses on the discomfort of unmaintained green environment. Therefore, in this study, we investigate subjects' biological reactions (cerebral blood flow and heart rate) and willingness to pay (WTP) for the improvement, presenting images of abandoned detached houses and woods as unmaintained green environment, and analyze the relationship between biological reactions and WTP.59 subjects joined this experiment. After a 60-second rest period, each subject sees the 4 unmaintained greenery image and 4 maintained greenery images, 5 seconds each. In order to consider the order effect, the order of unmaintained and maintained greenery images was alternated by half for each subject. In addition, data showing large fluctuations or trends during breaks were excluded from the analysis.As a result, 1) in case of abandoned detached house, the heart rate tended to increase when they see the "unmaintained greenery", and in case of abandoned woods, the heart rate tended to decrease when they see the "maintained greenery". 2) The heart rate variation differ by gender and presentation order of images. Females showed greater variation. Interestingly, there was a contrasting change in whether the maintained images were viewed first or later in both abandoned detached house and woods. 3) We cannot find the difference in cerebral blood flow. 4) There was no relationship between the presence or absence of changes in biological reactions and WTP. Though we need further investigation, we show the possibility of biological reactions to evaluate unpleasant green environment.