【摘要】：為研究斥水程度對(duì)土壤水分特征曲線的影響,該文基于滴水穿透時(shí)間法,人工配置7種斥水程度的黏壤土(L0~L6)和6種斥水程度的砂土(S0~S5),用高速離心機(jī)測(cè)定其土壤水分特征曲線,應(yīng)用van Genuchten-Mualem(VG)模型進(jìn)行擬合,得出VG模型水力參數(shù)。結(jié)果表明:在同一吸力條件下,斥水黏壤土的含水率比斥水砂土的高;隨著斥水程度增加,在相同吸力情況下,土壤含水率隨斥水程度增大而減小;斥水黏壤土的殘余含水率隨著斥水程度增加而減小,斥水砂土S0~S3的殘余含水率沒(méi)有差異,S4、S5的殘余含水率顯著減小;斥水黏壤土和砂土進(jìn)氣值的對(duì)數(shù)與斥水劑添加量呈負(fù)線性相關(guān);隨著斥水程度增加,田間持水率減小,凋萎系數(shù)沒(méi)有明顯差異,重力水增加,有效水和易有效水減小,易利用水比例隨著斥水程度增加而減小;對(duì)于斥水黏壤土,微孔隙(0.3~5μm)和小孔隙(5~30μm)含量隨著斥水程度的增加明顯減小,土壤空隙(≥100μm)隨著斥水程度的增加急劇增加;對(duì)于斥水砂土,中等孔隙(30~75μm)的含量隨斥水程度的增加明顯增加。該研究成果可為斥水土壤的入滲、蒸發(fā)和數(shù)值模擬提供理論支持。
[Abstract]:In order to study the effect of water repellent degree on soil moisture characteristic curve, seven kinds of clay loam (L0~L6) with water repellent degree and six kinds of sand (S0~S5) with water repellent degree were manually configured based on drip penetration time method. The characteristic curves of soil moisture were measured by high speed centrifuge and fitted by van Genuchten-Mualem (VG) model. The hydraulic parameters of VG model were obtained. The results showed that under the same suction condition, the moisture content of water-repellent clay loam soil was higher than that of water-repellent sand soil, and with the increase of water repellent degree, the soil moisture content decreased with the increase of water repellent degree. The residual moisture content of water-repellent clay loam decreased with the increase of water repellent degree, but the residual moisture content of S0~S3 of water-repellent sandy soil was not different, while the residual moisture content of S _ 4 / S _ 5 decreased significantly. The logarithm of intake value of water repellent loam and sandy soil is negatively linear with the addition of water repellent. With the increase of water repellent degree, the field water holding rate decreased, the wilting coefficient was not significantly different, the gravity water increased, the available water and easy available water decreased, and the ratio of easily available water decreased with the increase of water repulsion degree. For water-repellent clay loam, the contents of micropores (0.3 ~ 5 渭 m) and small pores (5 ~ 30 渭 m) decreased obviously with the increase of water repellent degree, and soil voids (鈮，

本文編號(hào)：2393443