宁夏典型土壤持水性能及收缩特征

Soil Moisture Curve and Shrinkage Characteristic of Different Areas in Ningxia

为了探明宁夏不同生态区域土壤在脱水过程中的收缩特性,选择六盘山(LP)、贺兰县(HL)、同心县(TX)和盐池县(YC)四地的土壤对其脱水过程中的土壤水分特征曲线进行测定,并对其比容积、容重等参数进行了研究。结果表明:V-G模型对4种土壤水分特征曲线的拟合均具有较高的精度,土壤有效收缩度相对大小依次为HL>TX>YC>LP,收缩最大的为黏土,在吸力值在400cm时HL有效收缩度为0.23。脱水过程中比容积曲线表现为LP曲线比较平缓,其余三种土壤跳跃性比较大。脱水后容重相对大小为LP>TX>YC>HL,这与土壤各颗粒级配组成密切相关。

In order to understand soil shrinkage characteristics in the dewatering process in the different eco- logical regions of Ningxia, soil samples in Liupan Mountain （LP）, Helan County （HL）, Tongxin County （TX） and Yanchi County （YC） were collected. Dehydration the process of soil moisture characteristic curves and soil specific volumes, bulk densities and other parameters were measured. The results show that VG model can precisely describe the soil moisture curves, effective soil shrinkage of the relative size decreases in the order. HL〉TX〉YC〉LP, the contraction of clay soil is the largest, when the suction value is 400 cm, the effective degree of shrinkage of HL is 0.23. Performance of a specific volume curve of LP is relatively gentle during dehydration, the fluctuation of the curves of the other three soils is relatively large. Relative bulk densities decrease in the order. LP〉TX〉YC〉HL after dehydration, which is closely related to parti- cle size distribution of each soil.