【摘要】 为揭示土壤饱和渗透系数的变化规律,在江汉平原杨林尾-陆溪口地区分别采用Guelph入渗仪和改进的TST-55型土壤渗透仪开展了土壤饱和渗透系数实验。结果表明:采用Guelph入渗法在粉砂质黏壤土中测得冲积物饱和渗透系数相对较大,数量级在10^-2～10^-1之间,最高达到7.50×10^-1 m/d,最小为1.40×10^-2 m/d;湖积物饱和渗透系数在1.86×10^-3～4.99×10^-2 m/d之间;而残积物的为6.05×10^-3 m/d,相对较小;同为粉砂壤土,相同水位埋深条件下甘蔗地和小麦地（同为耕地）的土壤饱和渗透系数明显比林地的大,这与土壤翻耕及根系、虫孔发育等有关;在相同水位埋深条件下,粉砂壤土的土壤饱和渗透系数普遍比粉砂质黏壤土的大,主要是因为粉砂质黏壤土比粉砂壤土的黏粒比重大、孔隙比相对较小的缘故。室内变水头达西法和Guelph入渗法测得的土壤饱和渗透系数分别介于5.43×10^-5～2.10×10^-3 m/d和1.57×10^-3～7.50×10^-1 m/d之间。室内变水头达西法所测结果明显偏小,主要原因包括:①Guelph入渗法进行现场原位测试时,土壤有效直径相对于室内变水头达西法使用的环刀直径要大得多;②室内变水头达西法所用土样为单一岩性,而Guelph入渗法为原位土层,常常具有双层或多层结构;③Guelph入渗试验期间恰逢雨季,地下水位埋深小,当支持毛细水带接近地表时,Guelph入渗试验将受支持毛细水的影响,从而使Guelph入渗法所测得的结果产生误差。更多还原

【Abstract】 In order to reveal the variation law of soil saturated hydraulic conductivity, the soil saturated hydraulic conductivity experiment was carried out by using Guelph infiltration instrument and modified TST-55 soil permeation instrument in Yanglinwei-Luxikou area of Jianghan Plain. The results show that the saturated permeability coefficient of alluvial deposits measured in the silty clay loam by Guelph infiltration method is relatively large, and the order of magnitude is between 10^-2-10^-1, with the highest 7.50×10^-1 m/d, and the minimum 1.40×10^-2 m/d. The soil saturated hydraulic conductivity of lacustrine materials is between 1.86×10^-3 and 4.99×10^-2 m/d. While the eluvium is 6.05×10^-3 m/d, relatively small. The soil saturated hydraulic conductivity of soils measured by indoor variable head Darcy method and Guelph infiltration method are between 5.43×10^-5-2.10×10^-3 m/d and 1.57×10^-3-7.50×10^-1 m/d. The results of the indoor variable head Darcy method are significantly smaller. This can be attributed to the following main causes. ①When the Guelph infiltration method is used for on-site testing in situ, the effective diameter of the soil is much larger than the diameter of the ring cutter used in the indoor head change method; ②The soil sample used in the indoor variable head Darcy method is a single lithology, while the Guelph infiltration method is an in situ soil layer, which may have a double or multi-layer structure; ③The Guelph infiltration test coincides with the rainy season, and the groundwater level is buried deep. When the capillary band is supported close to the surface, the Guelph infiltration test will be affected by the support of capillary water, causing errors in the results measured by the Guelph infiltration method.更多还原