Ecological zoning and dynamic assessment of effectiveness in the Three Gorges Reservoir Area, China

Abstract

Human activities render ecological conservation a formidable challenge. The rational zoning and dynamic evaluation of ecological regions are critical for the protection of regional biodiversity and the promotion of ecological sustainability. Here, the InVEST-HFI model was used to evaluate both the habitat quality (HQ) and the human footprint index (HFI) of the Three Gorges Reservoir Area (TGRA), a representative ecologically vulnerable area in southwest China. Superimposition analysis was employed to identify eco-regional zoning types and the PLUS model was applied to simulate and evaluate the benefits of ecological zoning. The results showed that the overall HQ of the TGRA area is satisfactory, with high-grade HQ areas covering 50.16 % of the entire reservoir area, mainly distributed in the Hubei section. The HFI displays a spatial distribution pattern, with higher values concentrated in the southwest and lower values in the northeast; there was also a concentration of high-value areas in Chongqing. Based on the HQ and HFI, the TGRA can be divided into three ecological protection zone types—a strict ecological protection zone, accounting for 57.18 % of the total area and distributed in the head and belly of the reservoir; a habitat restoration zone, accounting for 17.45 % of the total area and distributed in the tail of the reservoir; and a moderate development zone, which is scattered along the main stream of the Yangtze River in the middle of the reservoir. Simulation projections of land use in the TGRA for natural development and zoning protection scenarios until 2035 revealed that the ecosystem service value (ESV) of the latter scenario is 2.25 billion yuan higher than that of the former. Ecological zoning management can improve the ESV of the TGRA. We demonstrated the effectiveness of utilizing the HQ and HFI measures in ecological zoning, thus providing a valuable reference for assessing its benefits.