Spatial correlation analysis between human disturbance intensity (HDI) and ecosystem services value (ESV) in the Chengdu-Chongqing urban agglomeration

The spatial correlation between human disturbances and ecosystem services carries profound implications, serving as a pivotal tool for quantifying the magnitude of human impacts on ecosystems and offering invaluable insights for the development of effective management and conservation strategies. This research endeavors to conduct an exhaustive analysis of the spatial patterns between human disturbance intensity and ecosystem services in the Chengdu-Chongqing urban agglomeration, as well as to explore the spatial associations between these two factors. In the paper, we conducted a comprehensive analysis of five key indicators of human pressure, namely population density, gross domestic product (GDP), land use type, transportation network and energy consumption. These indicators were carefully examined and utilized to create a spatial map depicting the integrated human disturbance intensity index in the Chengdu-Chongqing urban agglomeration area in the year 2020. Concurrently, we utilized the ESV equivalent factor method to estimate the ecosystem service value (ESV). Bivariate Local Moran Index and spatial autocorrelation analysis were introduced to quantitatively depict and visualize the spatial relationship between human disturbance and ecosystem services. This research provides valuable insights into the intricate patterns of human pressures and ecosystem services in urban agglomeration scale. The key findings are as follows. First, the integrated human disturbance intensity is relatively high in the hub parts of Chengdu, Chongqing, and Deyang, as well as the middle zone of the cities between Chongqing and Chengdu. Second, the high value of supply services is distributed in the periphery of the cities, while the value of supply services in the middle of the cities tends to be medium and low. The majority area in the middle of the entire study area has low and medium–low values of regulation and maintenance service. At the fringes, there are only a few cities with higher values, including Ya'an, Leshan, Deyang and the eastern part of Chongqing. The distribution of cultural service values is quite similar to the distribution of regulation and maintenance service values, with the low value areas being very large and located in the middle of the study area, while the high value areas are significantly smaller and scattered around the perimeter of the study area. Third, the global Moran's index of cumulative human disturbance is 0.798, indicating that human disturbance exhibits a significant spatial autocorrelation. The global Moran's index of ecosystem services is 0.410, indicating that ecosystem services present aggregation in space as well. Fourth, the Bivariate Moran′s I between human disturbance and supply services is −0.221. The Bivariate Moran′s I between human disturbance and regulation and maintenance service is −0.212. And the Bivariate Moran′s I between human disturbance and cultural services is −0.462, which shows a stronger negative correlation.