The relationship between acoustic characteristics and landscape elements with different hydrodynamic environment in Jiuzhaigou World Heritage Site, China

Abstract

A large number of studies are exploring the applicability of acoustic indices, and studies have been conducted to reveal the relationship between environmental factors (vegetation, microclimate, geology, etc.) and acoustic indices in different temperature zones and under different ecosystem conditions. On the one hand, studies in water ecosystems with different hydrodynamic characteristics are relatively lacking, and on the other hand, the accuracy of acoustic index calculation under the influence of continuous hydrodynamic features still needs to be continuously explored. This study explores whether acoustic indices can provide relatively accurate revealing results of landscape characteristics under different hydroacoustic intensities. In this paper, we collected 19 typical hydrodynamic soundscape resources including waterfalls, streams and haizi in Jiuzhaigou World Natural Heritage Site, a typical water ecosystem environment, as the object of the soundscape study. The landscape features were identified using semantic segmentation image techniques, and some specific feature factors were scored by eight people to complement. The relationships between 7 commonly used acoustic indices (i.e., Bioacoustic Index-BIO, Acoustic Entropy Index-AEI, Acoustic Diversity Index-ADI, Acoustic Evenness Index-AEI, Acoustic Complexity Index-ACI, Normalized Difference Soundscape Index-NDSI, Acoustic Richness Index-AR) and landscape elements were explored. The results show that (i) different hydrodynamic characteristics cause great differences among the acoustic indices, and (ii) the extent to which acoustic indices characterize landscape elements varies under different hydrodynamic characteristics. The study reveals the characteristics of the hydrodynamically dominated acoustic environment in Jiuzhaigou, and collects response data for subsequent monitoring of environmental changes using acoustic indices, as well as laying the foundation for conservation management.