Environmental Impact and Cost Analysis of Ecological Buffer Zones from an LCA-LCC Perspective
To identify optimal watershed remediation pathways under environmental and economic dimensions, an integrated environmental-economic impact assessment framework combining life cycle assessment (LCA) and life cycle costing (LCC) based on openLCA was established, using 1 m³ of treated wastewater as the functional unit. This framework comprehensively evaluated the environmental impacts and economic costs of three ecological buffer measures—constructed wetlands, ecological intercepting ditches, and vegetation restoration projects—in non-point source pollution control. The results indicated that constructed wetlands offer the optimal environmental-economic profile, featuring the lowest comprehensive cost (¥1.01 yuan/m³) and the lowest load across most environmental impact categories, with only slightly higher land resource consumption intensity. Ecological intercepting ditches exhibited higher impacts in areas such as metal resource consumption due to the use of rebars and base fertilizer inputs, resulting in a moderate comprehensive cost (¥1.57 yuan/m³). Vegetation restoration projects incurred the highest comprehensive cost (¥61.14 yuan/m³) and produced the most significant environmental impacts, with elevated indicators such as human carcinogenic toxicity. This primarily stemmed from the extensive use of concrete grass pavers and base fertilizer in rural river sections. These findings provide quantitative references for environmental-economic integrated evaluation and decision-making regarding ecological buffer zone engineering schemes in similar watersheds.