Abstract: Tailings ponds are special functional units with high risks and disturbances during the mining process,and their ecological environment quality shows significant differences at different life cycle stages.Existing studies mostly focus on the entire mining area,lacking systematic characterization of the long-term evolution laws of the ecological environment of tail ings ponds.Therefore,this study takes the Huangmailing phosphogypsum tailings pond in Hubei Province as an example,based on the long-term Landsat remote sensing images from 1994 to 2024,and selects the MSAVI and BSI indicators to replace the o riginal greenness (NDVI) and dryness (NDBSI) factors in combination with the environmental characteristics of the tailings pond.The improved remote sensing ecological index (TP_RSEI) is constructed by weighting the first and second principal components for quantitative evaluation.The research results show that:The average correlation degree of TP_RSEI is 0.70, which is better than that of a single indicator,and can effectively represent the ecological characteristics of the study area.In the temporal dimension,the mean value of TP_RSEI in the study area decreased from 0.64 to 0.52 over 30 years,with a de cline of 18.75%,showing a fluctuating evolution pattern of "first degradation and then improvement",which is highly coupled with the full life cycle stages of the tailings pond,namely "construction-operation-shutdown-restoration".In the spatial pattern, the ecological environment shows a significant feature of "degradation in the center and recovery at the edge".The high-inten sity storage during the operation period led to ecological degradation,while the closure and restoration projects promoted the gradual improvement of ecological quality.This study reveals the evolution laws of the ecological environment quality of tailings ponds from a full life cycle perspective.The proposed TP_RSEI method effectively enhances the applicability of the remote sensing ecological index in the complex scenarios of tailings ponds,providing scientific basis and technical support for the as sessment of ecological restoration effectiveness,regulatory decision-making,and the construction of green mines.

Key words: 　remote sensing ecological index,full life-cycle of tailings pond,ecological environmental quality,spatiotempo ral variation,ecological restoration