Ecosystem sensitivity and landscape vulnerability of debris flow waste-shoal land under development and utilization changes

Abstract

Debris flow waste-shoal land (DFWSL) is a new type of ecosystem in ecologically fragile areas of debris flows that is extremely sensitive to natural and anthropogenic disturbances. Existing studies have focused on the availability and utilization of DFWSL and impact analysis of DFWSL use with external environmental changes but have neglected to evaluate the vulnerability and sensitivity of the DFWSL system itself. To gain a more in-depth understanding of the sensitivity and vulnerability of the DFWSL system and the spatial relationship between them. In this study, a comprehensive and general methodology was developed to quantitatively illustrate the spatiotemporal changes of sensitivity and vulnerability of DFWSL and explore the spatially heterogeneous relationships between these relations and several socio-ecological drivers, integrating land transfer matrix, global Moran’s I and local Moran’s I, geographical detector, and multi-scale geographically weighted regression (MGWR) methods. Results show that the main land use types in the DFWSL, from 2014 to 2022, were cultivated and construction land. During that period, the area of cultivated land and water area decreased by 24.3% and 49.36%, respectively, while the area of forest land and construction land increased by 42.29% and 31.71%, respectively. Overall system sensitivity decreased during this period. The severe sensitive (Mid-High and High) area gradually decreased to the periphery areas and river basin outflows. The mild sensitive area increased (81% in 2014, 83% in 2018, and 90% in 2020) and was mainly located in the central area, mainly affected by elevation, rainfall, slope, and NDVImax. Landscape vulnerability (fragmentation) was mainly present in the central area, which was dominated by human activity (cultivated and construction land). The distributions of landscape vulnerability and sensitivity displayed a non-correspondence spatial correlation. This study improved our understanding of the spatial distribution characteristics of vulnerability and sensitivity of DFWSL and provided a basis for devising solutions to problems associated with disaster reduction and development.