The variation of air resistance in concave green spaces and its influence on rainwater seepage process
This article mainly studied the changes in soil pressure in concave green spaces under different rainfall conditions and soil properties and their impacts on the rainwater storage and infiltration process.The results showed that the air pressure in concave green spaces was generated later with deeper soil horizons.The maximum air pressure in the surface soil(0～10 cm)and middle soil(10～30 cm)was similar,while the maximum air pressure in the bottom soil(30～40 cm)decreased,mainly due to the decrease in soil air content as the depth of the soil layer increases.The air pressure inside the concave green space can be divided into four stages:latent period,ascending period,smooth period,and slow descending period.The pressure inside the concave green soil was significantly affected by rainfall intensity.When the rainfall recurrence period increased from 1 a to 3 a,the peak pressure in the soil increased from 697.8 Pa to 1 101.5 Pa.The generation of pressure affected the infiltration of the water accumulated at the surface.When the rainfall intensity increased from 1 a to 3 a and 5 a,the required infiltration time extended from 320 min to 750 min and 960 min,respectively.The pressure inside the soil increased with the increase of soil moisture content.When the soil moisture content increased from 2.1％to 19.3％,the maximum pressure increased by 97％.During the stable infiltration period,the infiltration rate decreased from 0.68 mL·s-1 to 0.06 mL·s-1,and the runoff infiltration amount within 60 minutes decreased by 98.8％.The vegetation cover had a relatively smaller effect on the air pressure inside the concave green space.The research results can provide guidelines for improving the regulation and storage efficiency of sunken green spaces for rainwater runoff and enhancing the absorption,storage,and slow-release effects of low-impact facilities on rainwater.
concave green spaceair resistancerainwater runoff infiltrationinfiltration capacity
国家科技期刊平台
NSTL
万方数据
