Despite the increasing awareness regarding the importance of ecologically fragile areas in maintaining human well-being, there is a lack of understanding of the comprehensive quantification of the basin-scale ecosystem services. In this study, based on risk zoning, the regional difference coefficient (RDC) was introduced into an existing method proposed by Costanza to value the ecosystem services. The modified method was then applied to value the ecosystem services of a debris flow alluvial fan in Awang basin, Yunnan, China from 2012 to 2018. The results indicated that in the debris flow area, the ecosystem service of water area is of great value; however, because of the limited area, the transformation between the adjacent land types can be easily triggered owing to human or natural influence. During this period, the ecosystem service demonstrated a downward trend, which could attribute to a decrease in the water area with a larger ecosystem service and an increase in the area of the construction land that led to the considerable depletion of the ecosystem service. The proposed modified method to value ecosystem services can be a valuable means to reflect the present situation of a basin-scale ecosystem and the effect of ecological restoration.

尽管人们越来越意识到生态脆弱地区对维持人类福祉的重要性，但仍缺乏对流域规模生态系统服务的全面量化的理解。在这项研究中，基于风险分区，将区域差异系数（RDC）引入了Costanza提出的评估生态系统服务价值的现有方法中。将该方法应用于2012-2018年云南省阿旺盆地泥石流冲积扇的生态系统服务价值评价。结果表明，在泥石流区域，水域生态系统服务具有重要价值。但是，由于面积有限，由于人为或自然的影响，相邻土地类型之间的转换很容易触发。在这段时期，生态系统服务量呈下降趋势，这可能是由于生态系统服务量较大的水域面积减少以及建设用地面积的增加导致生态系统服务量大量减少。提出的对生态系统服务价值进行评估的改进方法可能是反映流域规模生态系统现状和生态恢复效果的宝贵手段。