基于逐步回归模型和EM38电磁感应分析的干旱区人工水库区域土壤盐分测定——以新疆八户地水库为例

measurements in reservoir zone of northwest arid region——A case study in Bahudi reservior,Xinjiang,China

通过电磁感应仪EM38与传统采样测定方式,建立了磁感式表观电导率和土壤盐分之间的回归模型,运用该模型对新疆厅台县八户地水库大坝外侧的土壤盐分进行了预测,并利用Kriging插值方法,绘制了0～20、20～40、40～60、60～80cm各层土壤盐分的空间分布图.结果表明:0～20、20～40、40～60、60～80cm土壤盐分预测模型的复相关系数分别达到0.62、0.73、0.76、0.82,可以看出随着土壤深度的加深,拟合效果也越好;各层土壤含盐量在10g/kg以上的分布面积占调查区域的80%以上,属于盐土;土壤盐分在垂直方向上大致呈"反C"型分布,在20～60cm土层上有明显积聚;土壤盐分在空间上由南向北呈逐渐升高的趋势,在水库大坝附近和靠近水渠方向的土壤含盐量明显降低.

Through EM38 and traditional way sampling measurements, a regression model was estab- lished between the magnetic induction conductivity and soil salinity. The model was applied to predicted on the soil salinity outside the dam. The spatial distribution map was drawn using Kriging method about soil salinity of 0-20,20-40,40-60,60-80 cm layers. The results showed that the multiple correlation coefficient of soil salinity prediction model was 0. 62,0.73,0. 76,0. 82 in different layers, respectively. The soil salt contents in each layer over 10 g/kg distribution area were more than 80% of the survey area, belong to the saline soil. Soil salinity increased in space by south northerly.