基于土地利用的厦门市生态水文调节服务评估

生态系统具有重要的水文调节服务，通过对降水截留、过滤、吸收等手段，能够起到削峰补枯、缓和地表径流、增加地下径流的作用.以厦门市为研究对象，采用SWAT（soil and water assessment tool）水文模型评估了2015年厦门市生态系统水文调节服务；以土地利用为驱动变量，对2010年厦门市生态水文调节服务进行了评估，分析近年来厦门市加快城市绿化和海绵城市建设背景下土地利用变化对厦门市生态水文调节服务的影响.结果表明:2015年厦门市生态水文调节量为5.43×108 m3，时空差异较为明显.从各辖区来看，位于北部山区的同安区调节量（2.91×108 m3）最高，单位面积生态水文调节量（44.61×104 m3/km2）亦最高；建成区内的湖里区调节量和单位面积调节量均最低.从年内分布来看，5—9月生态水文调节量占全年的84.96%，生态系统有效减缓了径流输出，起到削峰的作用；10—11月，生态系统通过拦蓄降水，将其转换为土壤水和地下径流，使得该时期的实际径流大于潜在径流，起到补充枯期径流的作用.在相同气象条件下，2010年和2015年厦门市生态水文调节能力的空间分布整体一致，相比于2010年，2015年厦门市生态水文调节能力有明显提高，各辖区调节量和单位面积调节量均有所增加.研究显示，厦门市生态水文调节服务受气象条件和土地利用的共同作用，降水量越大，生态水文调节量越大，并且北部高植被覆盖区的生态水文调节能力高于南部建成区. 

Assessment of Ecological and Hydrological Regulation Service of Land Use in Xiamen City

Ecosystem has important hydrological regulation service such as precipitation interception, filtration and absorption, which can reduce the flood peak, smooth the surface runoff and increase the subsurface runoff. In this paper, the SWAT hydrological model was adopted to evaluate the ecological and hydrological regulation service of the ecosystem in Xiamen City in 2015. Then, the land utilization situation of Xiamen City in 2010 was utilized to calculate the impacts of the city greening and sponge city construction on the ecological and hydrological regulation functions. The results show that the amount of ecological and hydrological regulation functions in Xiamen City in 2015 was 543 million m³, and there were obvious differences in the spatial and temporal distribution. For instance, the Tong''an District had the highest total volume of 291 million m³ and per unit of 44.61×10⁴ m³/km², while the Huli District had the lowest values. In a single year, 84.96% of the hydrological regulation occurred in the period from May to September, which effectively reduced the flood peak. From October to November, the actual runoff was higher than potential runoff because the ecosystem resulted in flood water transfer into soil and groundwater systems to replenish the runoff in dry season. Under the same meteorological condition, the overall hydrological distributions in Xiamen City in 2015 were almost the same as that of 2010, and the ecological and hydrological regulation ability for all regions were improved. The results indict that the ecological hydrological regulation ability in Xiamen City is affected by meteorological conditions and land use:the more precipitation, the higher ecological hydrological regulation ability; the north mountain area with high vegetation coverage has higher ability than that of the southern urban area.