A bi-scale assessing framework for aesthetic ecosystem services of villages in a world heritage site

The relative spatial scale relationship of observers and ecosystem and their aesthetic dynamic interaction process are fundamental to evaluation and optimization of aesthetic ecosystem service (AES). A comprehensive and efficient framework for the assessment of AES is lack in the integration of scale relationship and dynamic process. This study took 9 villages in 4 different developmental stages (traditional, folk, rapidly changed, newly built) in Honghe Hani Rice Terraces, a world heritage site, as the research object. From two scales, viewing from inside and outside, the bi-scale assessing framework was established, which includes the three components of interaction process, connection area (as precondition of interaction), quality (as result of interaction), and influencing factors of quality (elements' characteristics of villages). Among them, the connection areas were evaluated with visual and traffic accessibility along the route. The quality and influencing factors were evaluated through participatory preferences methods by expert group. The influencing factors include 9 characteristics, such as, space size, architecture layout, vegetation species richness, color diversity. The results suggested that villages with high AES quality and low accessibility need to be optimized, and the key influencing factors are space size, architecture layout, color harmony and surrounding sanitation. Therefore, the bi-scale assessing framework can provide important references for decision making and visual protection regulations on the villages.