常用绿地土壤改良材料对土壤水分入渗的影响

Effects of Commonly Modified Materials on Soil Water Infiltration in Green Belt

利用一维垂直土柱法研究几种常用的绿地土壤改良材料及其不同配比对土壤水分入渗的影响,结果表明:土壤水分稳定入渗率、累积入渗量和湿润峰下移距离随土壤含砂量和粒径的增加而显著增加;绿化植物废弃物能提高土壤入渗及湿润峰下降深度,但单独应用效果不明显;脱硫石膏增加土壤入渗,加快湿润峰下移速度;但表施聚丙烯酰胺阻碍土壤水分下渗。Kostiakov入渗模型(I=Kt^(1-α))及幂函数(F=at^b)分别能很好地拟合几种改良材料的累积入渗量以及湿润峰随时间的变化,拟合系数R^2均在0.99以上,且模型中各项指标均较好地表征了几种改良材料的初始累积入渗量、土壤入渗能力的衰减程度及湿润峰变化。以体积比70%土+10%砂+20%绿化植物废弃物+0.5kg/m^3脱硫石膏配比对绿地雨水入渗和蓄积能力最佳。

One dimensional vertical soil column method was used to study the influence of soil water infiltration by several commonly used soil modified material and it＇s ratio on green belt. The results showed that with the increase of sand content and particle size, soil water stable infiltration rate, cumulative infiltration amount and the down distance of wetting front significantly improved. In addition, greenery waste could improve soil infiltration and wetting front depth of the depression, but the result was not obvious. Also,desulfurization gypsum could improve soil infiltration and wetting front depth of the depression, while the PAM used in the soil surface inhibited soil infiltration capability. Kostiakov infiltration model （I=Kt^1-a） and power function （F=at^b） were well fit cumulative infiltration and wetting front changed with time of various modified mate- rials, the fitting coefficient R2 were all above 0.99, and the indexes in the model were well characterized soil infiltration performance of different soil modified materials, such as initial cumulative infiltration, attenuation degree of infiltration and the change of wetting front. Finally, the best ratio of soil modified materials that this paper proposed was made of 70% soil, 10% sand, and 20% greenery waste with 0.5 kg/m^3 desulfurization gypsum in volume was to play rainwater collection and drainage function for green belt.