海绵城市近几年在中国建设规模逐步扩大。基于生命周期视角定量化分析海绵城市源头设施建设和运行过程中的环境、经济影响与效益，可为海绵城市建设提供科学而全面的依据。目前国内外关于源头设施生命周期环境与经济评价的研究尚存不足：研究所涉及的环境影响和设施种类单一；环境与经济集成评价研究很少；较少涉及灰绿耦合系统环境与经济集成分析；研究尺度较小。基于上述问题，本研究提出了生命周期视角下的海绵城市源头设施环境与经济集成评价方法，从15种中间点环境影响类别和3种终点环境影响类别以及内部与外部经济成本和效益综合量化分析源头设施建设产生的生命周期环境、经济影响和效益，并在城市内场地层面和城市试点区层面进行应用，从不同受众角度指导海绵城市建设。在场地层面，首先针对公共管理与公共服务用地的源头设施建设开展了生命周期环境与经济集成评价，识别了关键影响因子。根据运行阶段对径流水量和水质的控制计算环境与经济效益，总环境影响回收期在8年以内，总经济成本回收期在2年以内。该结果比其他研究中相同类别回收期均短，说明源头设施建设综合效益可观。该研究结论可为当地政府部门决策提供量化依据。场地层面另一项研究是针对住宅用地中灰绿耦合系统与灰色系统进行生命周期环境与经济量化对比，并结合绿色建筑补贴政策分析经济成本与效益。计算结果表明，考虑财政补贴后，灰绿耦合系统建设阶段经济成本比灰色系统低30%，运行阶段产生的环境与经济效益使得环境影响与经济成本的回收期均在2.5年之内。如不考虑财政补政策，总成本回收期会增加2年。该结果可为房地产开发商投资建设提供量化依据。在城市试点区层面，按照年降雨径流控制率将第一批国家海绵城市试点城市进行分类并分别进行源头设施生命周期环境与经济集成评价。就目前各试点海绵城市源头设施建设情况，海绵城市源头设施运行阶段产生的环境效益与经济效益均很显著，现有三类试点城市水体富营养化、水体生态毒性、海洋富营养化和水体消耗的环境影响回收期均在2年以内。总经济成本的回收期在8年以内（II区回收期7.47年，III区4.35年，IV区3.9年）。II区总经济成本比IV区高58%，但总经济效益却比IV区低18%。II区城市多年平均降雨量为III区和IV区的1/3，但现状过多建设了环境与经济影响较大的调蓄池和人工湿地，未来应偏向于建设相对自然、环境与经济影响较小的设施。
The construction scale of Sponge City source control facilities in China increased dramatically recent years. Quantitatively evaluating the environmental and economic impact generated from construction stage and environmental and economic benefit generated from operation stage through life-cycle perspective can provide scientific and comprehensive information for future Sponge City construction. There are some issues of worldwide research of life-cycle environmental and economic assessment for Sponge City need to be improved. Such as only considered certain impact or facility, the integrated environmental and economic assessment study is rare, few research considered coupled green and gray infrastructure assessment; and the scale of study is small. Research needs to address these certain issues to present a more systematic and credible assessment. In order to guide the construction of Sponge City from different levels, this study raised a integrated environmental and economic assessment method, through 15 midpoint impact categories, 3 endpoint impact categories, internal and external economic cost and benefit to evaluate Sponge City construction in China, and applies it to the site and city pilot area level.The Sponge City source control facilities construction in the public service land is firstly studied in the site level. This research identifies key factors of different practices and calculates the environmental and economic benefit generated from operation stage. The payback time of environmental impact is within eight years and the payback time of total economic cost is within two years. The payback time is shorter than that in other studies, which showed the comprehensive benefit of source control facilities is considerable. Useful information identified will help policymakers make decisions with regard to Sponge City construction problems. Another site level research is focused on the integrated green and gray infrastructures in the residential area. Calculated results present that combined with the green building subsidy policy, the internal economic cost of integrated green and gray infrastructures is 30% lower than the gray infrastructure. The environmental benefit and economic benefit generated from operation stage of integrated green and gray infrastructures can make the payback time of environmental impact and economic cost within 2.5 years. If green building subsidy policy isn’t considered, the payback time of total economic cost will increase two years. The conclusion will provide quantitative support for the investment and construction of real estate developers.At the city pilot area level, 16 national pilot cities are classified and studied according to volume capture ratio of annual rainfall. At the current Sponge City construction situation, the environmental and economic benefits of Sponge City source control facilities are considerable, the payback time of aquatic eutrophication, freshwater ecotoxicity, marine eutrophication, and water depletion is within two years. The payback time of the total economic cost is within eight years (zone II needs 7.47 years, zone III needs 4.35 years and zone IV needs 3.9 years). The economic cost of zone II is 58% higher than zone IV, but the economic benefit is 18% lower than zone IV. The average annual rainfall of the cities in zone II is 1/3 of that in zone III and zone IV, but currently overbuilds regulation and storage ponds and constructed wetlands which have higher environmental and economic impacts. So zone II should prefer to build more natural and environmental and economic friendly practices in future.
