广州市不同功能城市绿地表层土壤入渗特征

Surface Soil Infiltration Characteristics of Urban Green Space with Different Function in Guangzhou City

为探索广州市不同功能城市绿地表层土壤入渗特征,采集广州市公园绿地(草坪和林地,PGL,PGW)、道路绿地(RG)、广场绿地(SG)表层土壤(0~15 cm),测定了土壤初始入渗速率、稳定入渗速率、容重、含水量、孔隙度、有机碳(SOC)、全氮(TN)、全磷(TP)等理化性质,分析了土壤初始入渗速率、稳定入渗速率与土壤理化性质之间的相关关系。结果表明:研究区域80.9%的样点土壤容重高于自然土壤平均水平;不同功能城市绿地表层土壤容重平均值大小表现为SG(1.50 g·cm^(-3))>PGL(1.45 g·cm^(-3))>PGW(1.44 g·cm^(-3))>RG(1.40 g·cm^(-3)),而孔隙度平均值大小恰好相反,表现为RG(47.10%)>PGW(45.61%)>PGL(45.22%)>SG(43.23%),SG、RG两种功能绿地之间土壤容重、孔隙度大小均存在显著性差异;初始入渗速率整体上高于稳定入渗速率,但在不同功能绿地之间差异不显著;相关性分析结果显示研究区域绿地表层土壤初始入渗速率和稳定入渗速率受土壤含水量、有机碳、全氮影响显著,而受土壤容重、孔隙度、全磷影响则不显著。综上所述,研究区域绿地表层土壤受压实比较严重,入渗性能与土壤含水量、有机碳、全氮密切相关。

In order to explore surface soil infiltration characteristics of urban green space with different functions in Guangzhou city,surface soil samples(0-15 cm)were collected from park green space(PGL,and PGW),road green space(RG),and square green space(SG),soil physic-chemical properties such as initial infiltration rate,stable infiltration rate,bulk density,moisture content,soil porosity,soil organic carbon(SOC),total nitrogen(TN),total phosphorus(TP),etc,were determined,to analyze the correlation of soil initial infiltration rate,stable infiltration rate with soil physic-chemical properties.The results indicated that the soil bulk density of 80.9%of the sample soil was higher than the average level of natural soil.The average soil bulk density under different green spaces showed as follows SG(1.50 g·cm^(-3))>PGL(1.45 g·cm^(-3))>PGW(1.44 g·cm^(-3))>RG(1.40 g·cm^(-3)),while the average soil porosity was exactly the opposite,showed as RG(47.10%)>PGW(45.61%)>PGL(45.22%)>SG(43.23%),the difference of bulk density and soil porosity between SG and RG were significant.The initial infiltration rate was generally higher than the stable infiltration rate,but not significant in urban green spaces with different functions.The correlation analysis results showed that soil initial infiltration rate and stable infiltration rate were significantly affected by soil moisture,SOC,and TN,while not significantly affected by bulk density,soil porosity,and TP.In conclusion,the surface soil of green spaces is severely compacted in the study area,the surface soil infiltration characteristics are deeply influenced by soil moisture content,SOC,and TN,the surface soil infiltration performance of road green spaces is good,and results from this study would provide scientific basis the management of urban green space in Guangzhou.