半干旱黄土区土壤水分垂向变异性的研究

Study on Vertical Variability of Soil Moisture Content in Semiarid Region of Loess

以甘肃省兰州市孙家岔流域为研究对象,利用1981—1983年、2011年的实测土壤水分资料,采用地质统计法分析了该流域土壤水分的垂向变异特征。结果表明,球状模型对丰水年和平水年不同土地利用(梯田和荒坡)土壤水分垂向分布的变异函数拟合,经F值检验后为显著水平。在枯水年,球状模型对梯田的实验变异函数依旧拟合较好,而荒坡在枯水年二次线性模型对土壤水分垂向分布拟合较好,对枯水年雨季分析,发现土壤水分的时空间自相关也很弱。半干旱黄土区土壤水分垂向变异性的研究,可对该区不同土地利用的蓄水特征和土地规划利用提供一定的理论依据。

In the study, soil moisture and its vertiral variation in the Sunjiacha basin, Lanzhou City, Gansu Province, were measured by the soil water content from 1981 to 1983 and in 2011, and analyzed by geostatistics. The results show that after F-test statistic, spherical model came up to significant level for vertical distribution of soil moisture in wet year and normal year under different land-use type, such as terrace and wasteland slope. Vertical variation of soil moisture in terrace were also better described by spherical model in dry year. But vertical distribution of soil moisture in wasteland slope was better fitted by quadratic function model. Spatial autocorrelation during the rainy season is very weak in dry year. Study on vertical variability of soil moisture content in semiarid region of loess, can provide the theory basis for soil reservoir characteristics of different land use and land planning and utilization.