Watershed landscape ecological risk assessment and landscape pattern optimization: Take Fujiang River Basin as an example

Abstract

Landscape pattern optimization is an effective method to reduce the landscape ecological risks and construct ecological security pattern. Ten factors from three dimensions (nature, social, landscape pattern) were selected to construct the landscape ecological risk evaluation index system, and spatial principal component analysis was employed to do a comprehensive landscape ecological risk evaluation of Fujiang River Basin. Based on the results of landscape ecological risk assessment, the minimum cumulative resistance model was used to optimize the landscape pattern, and the ecological sources, corridors, nodes were obtained. The following results were found: the ecological risks faced by the Fujiang River Basin are obvious, mainly in medium and moderate-high ecological risk levels, covering an area of 19,898.91 km2 (accounting for 50.81% of the total area of the study area). The landscape ecological risk level in the upper reaches of Fujiang River Basin was higher than that in the middle and lower reaches, this distribution pattern significantly affected by nature and landscape pattern dimension factors. The optimized network ecological structure was consisting of 50 ecological sources, 65 ecological nodes, 63 auxiliary ecological corridors, and 1 main ecological corridor, which could reduce the risk of landscape ecology, improve the connectivity of landscape pattern of the study area. This research provided scientific references for planning and adjusting the ecological network and sustainable development of watershed ecological environment.