厦门市城市绿地雨洪减排效应评价

城市绿地在对雨水的渗透、滞留和调蓄方面具有非常显著的作用，能够有效削减城市的雨洪流量，缓解内涝压力.以海绵城市试点——厦门市为典型区，在日降雨数据、土地利用数据、土壤类型数据、城市绿地空间分布数据和城市建成区空间范围数据等多源数据的支撑下，系统评价了厦门市建成区城市绿地的雨洪减排效应.其中，雨洪减排效应的实物量通过SCS（Soil Conservation Service）模型进行评估，价值量则利用替代市场法进行估算.结果表明:2010年厦门市单位城市绿地削减的雨洪径流深为262.28 mm，削减的雨洪径流总量为4 385.40×104 m3，减排服务价值为2.75×108元；2015年单位城市绿地削减的雨洪径流深为335.77 mm，削减的雨洪径流总量为7 634.37×104 m3，减排服务价值为5.49×108元.城市绿地面积、降水量及其时程分配是影响城市绿地雨洪减排效应的关键因子，在其共同驱动下，2015年厦门市城市绿地的雨洪减排效应较2010年显著增加.研究显示，SCS模型在数据输入和参数率定等方面具有显著优势，能够在地理空间上连续模拟厦门市整个建成区的产流量，进而实现行政区单元和城市绿地类型单元雨洪减排效应的双重评价，3种城市绿地类型（乔木、灌木和草本）单位面积的雨洪减排效应并无明显差异，受绿地面积支配，厦门市80%的城市绿地雨洪减排效应由乔木绿地产生. 

Assessment of the Effect of Urban Green Space Landscape on Reduction of Storm Water Runoff in Xiamen City

Research on the effect of urban green space landscape on the reduction of stormwater runoff is urgently needed for the construction of spongy city and the estimation of ecosystem services. Based on the multi-source data including daily rainfall, types of land use, soil, urban green space landscape, and the built-up area of Xiamen City, the effect of urban green space landscape on the reduction of stormwater runoff was evaluated for 2010 and 2015. First, by using a hydrological model SCS (Soil Conservation Service), the stormwater runoff of different types of land use was estimated for each rainfall event. Second, the annual reduction of the amount of runoff caused by the urban green space landscape was estimated, which was defined as the sum of the runoff differences between urban green space landscape and other land use types during each rainfall event. Finally, the ecological service values were calculated by the product of reservoir construction cost per unit volume of water and the total amount of runoff reduced by the green space landscape. In 2010, the depth of the stormwater runoff reduced was 262.28 mm per unit area of the urban green space landscape. The total amount of stormwater runoff reduction was 4385.40×10⁴ m³, and the ecological service values produced was 2.75×10⁸ RMB. In 2015, the depth of the stormwater runoff reduced was 335.77 mm per unit area of the urban green space landscape. The total amount of stormwater runoff reduction was 7634.37×10⁴ m³, and the ecological service values produced were 5.49×10⁸ RMB. The method proposed in this paper makes it possible for us to evaluate the reduction effect of urban green space landscape on stormwater runoff at both land use and district scale. The results show that the reduction effect of urban green space landscape on stormwater runoff is dominated by the area of green space landscape and the amount of annual rainfall as well as its seasonal distribution. Consequently, the ecological values of urban green space landscape have increased significantly from 2010 to 2015.