盘式入渗仪法测定喀斯特洼地土壤透水性研究

研究土壤水入渗有助于了解喀斯特地区表层岩溶带对降水资源的调蓄作用。该文利用盘式负压入渗仪(盘径d=20 cm,负压h0=-20 mm)研究了桂西北喀斯特洼地典型剖面各层次土壤透水性。结果表明:各层土壤透水性能差异较大,具有随土层深度增加而减小的趋势,但菜地50-80 cm层大于20-50 cm层;菜地剖面0-10 cm层土壤近似饱和导水率(1.85×10-3cm/s)是20-50 cm层的5.2倍,玉米地剖面0-16 cm层土壤近似饱和导水率(2.21×10-3cm/s)是55-70 cm层的3.1倍;土壤比重、初始含水率同土壤入渗性能关系密切,与近似饱和导水率的相关系数分别为-0.676*和-0.841**。

Soil Water Infiltration Measurement by Disc Permeameter in Karst Depression

Soil water infiltration measurement is helpful to investigate the adjustive effects of epikarst on rainfall resource in karst area.Tension disc permeanmeter(d=20 cm,h0=-20 mm) was used to determine soil water infiltration in the typical soil profiles in karst depression of northwest Guangxi.The results showed that the differences of soil infiltration capability were obvious in the soil profile,and it had a tendency to decrease with the increase in soil depth.However,infiltration rate of 50-80 cm soil layer was lager than that of 20-50 cm soil layer in vegetable land.The approximate hydraulic conductivity in 0-10 cm soil layer was 5.2 times higher than that in 20-50 cm soil layer in vegetable land,and it was 3.1 times higher in 0-16 cm soil layer than that in 55-70 cm soil layer in corn land.Soil specific gravity and initial water content had a close relationship with soil infiltration,and their correlation coefficients with hydraulic conductivity were-0.676* and-0.841*respectively.