• • Constructed wetlands achieve the lowest comprehensive cost at ¥1.01 yuan/m³ and exhibit the lowest environmental load across most impact categories, with only slightly higher land resource consumption intensity, making them the preferred environmental-economic option for non-point source pollution control.
• • Ecological intercepting ditches show moderate comprehensive cost (¥1.57 yuan/m³) but higher impacts in metal resource consumption (54.60% contribution from rebar) and other categories due to rebar and base fertilizer inputs, indicating a need to optimize material selection.
• • Vegetation restoration projects have the highest comprehensive cost (¥61.14 yuan/m³) and the most significant environmental impacts, with human carcinogenic toxicity elevated, primarily driven by concrete use (73.73% contribution) and base fertilizer, highlighting the environmental burden of concrete-intensive engineering.
• • Life cycle environmental costs dominate total costs across all three measures, accounting for 77.83% (constructed wetlands), 92.80% (ecological intercepting ditches), and 90.98% (vegetation restoration) of comprehensive costs, underscoring the necessity of integrating full life cycle environmental impacts into decision-making for watershed restoration projects.