黄河三角洲农田土壤含水率空间变异特征研究

Spatial Variability of Soil Water in Yellow River Delta

基于传统统计学和地统计学方法,定量分析了灌水前、后田块尺度下土壤含水率的空间变异性。结果表明,除灌水前10～20cm土层土壤含水率呈非正态分布外,其余各土层含水率均服从正态分布;随着土层深度的加深,灌水前、后各土层含水率均逐渐增加;除灌水前20～40cm土层及灌水后10～20、20～40cm土层土壤含水率呈中等变异性外,其余各土层均呈现弱变异特征;除灌水后20～40cm及40～60cm土层属于指数模型外,其余各土层含水率最优拟合模型为球状模型;灌水前、后各土层含水率均表现为强空间自相关性。

The descriptive statistics and geostatistics were used to quantitatively analyze field-scale spatial variability of soil water content in the vertical and horizontal directions before and after irrigation. The results showed that soil water content increased with depth. Soil water content showed strong spatial correlation characteristics except the 20 to 40 cm and 40 to 60 cm layers with a moderate spatial correlation after irrigation. According to semivarianee analysis, except that 20 to 40 em and 40 to 60 cm layers belonged to the exponential model, the rest belonged to the spherical model after irrigation. Soil moisture for all layers showed strong spatial autocorrelation before and after the irrigation.