合肥市绿地土壤水分入渗性能研究

为探明影响城市绿地土壤水分入渗性能的限制因子，提高城市绿地在雨水径流调蓄中的作用，采用双环入渗法研究了合肥居民区、公园、道路绿化带（市政绿地）和文教区（校园）等不同类型绿地的土壤水分入渗特征及其与质地、容重和空隙度等土壤物理性质之间的关系。结果表明：合肥市不同功能区绿地土壤入渗速率在0~40 min内下降较快，90~100 min后趋于平缓。土壤水分平均入渗速率呈现：公园绿地(2.42×10-5 m/s)>市政绿地(2.10×10-5 m/s)>小区绿地(0.62×10-5 m/s)>校园绿地(0.56×10-5 m/s)的规律。土壤稳定入渗率属于快和较快级别的占21.1%，中等及较慢等级的占78.9%。合肥市绿地土壤黏粒平均含量在37.6%~44.7%之间；土壤容重在1.22~1.68 g/cm3之间，均值均大于1.40 g/cm3；绿地土壤通气孔隙度在9.21%~17.6%之间，其中小区绿地(14.1%)＞市政绿地(13.9%)＞公园绿地(13.7%)＞校园绿地(11.3%)。研究结果为合肥市城区绿地土壤消减城市面源污染设计提供科学依据。

Investigation on Soil Water Infiltration in Different Urban Green Lands in Hefei City

In order to investigate the limit factors that influence soil water infiltration,and increase the adjusting and controlling roles in rain run-off in urban green land,soil infiltration in different functional urban green areas and the soil properties including particle size distribution,bulk density,the total porosity and aeration porosity of soil samples collected from green lands in Hefei urban were investigated.Results demonstrated that in different urban green lands the clay particles were between 37.6% and 44.7% in all the soil samples;the soil bulk density ranged from 1.22 to 1.68 g/cm3,and the mean bulk density was higher than 1.40 g/cm3.The aeration porosity were ranged from 9.21% to 17.6%,and its mean level were in the order：residential area（14.1%） municipal（13.9%） park（13.7%） campus（11.3%）.The sharp decreases of soil infiltration were found in the first stage（0-40 min）,slow decline in the second stage（40-90 min） and the stable stage（90-100 min） were tested by using the double rings infiltration methods.The mean soil infiltration velocity in different green areas expressed the following rules：park（2.42×10-5 m/s）municipal（2.10×10-5 m/s） residential area（0.62×10-5 m/s）campus（0.56×10-5 m/s）.About 21.1% of soil infiltration velocity was in the grade of medium fast and fast,and 78.9% of them in the medium slow and slow grade.Results from this study would provide critical facts for designing urban green lands and reducing urban non-point pollution through green land in Hefei.