空间插值法在土壤养分测定中的比较研究

Comparative Study of Spatial Interpolation Methods in Soil Nutrient Determination

土壤养分是维持植物生长的重要参数,空间插值是一种可以从离散的地面真实数据中得到空间分布趋势的方法。通过收集宿州市埇桥区麦田土壤养分178份样品数据,以缓效钾(SAK)作为插补因子,采用反距离加权法(IDW)、普通克里金法(OK)、样条函数法(Spline)和趋势插值法四种方法对其有效性和准确性进行比较评价。OK方法有球面模型、指数模型和高斯模型三种模型,采用平均误差(ME)和均方根误差(RMSE)对插补精度进行交叉验证。结果表明,OK方法优于其他方法。与球面函数和高斯函数相比,指数模型的性能最好,ME和RMSE分别为175.8073和-1.1261。

Soil nutrients are important parameters for maintaining plant growth.The spatial interpolation is an effective method for obtaining spatial distribution trends from discrete real data of the ground.The 178 samples of wheat soil nutrients were collected from Yongqiao District,Suzhou City.Slowly Available Potassium (SAK) was used as an interpolation factor.Inverse Distance Weighted (IDW),Ordinary Kriging (OK),Spline Function (Spline),and Trend Interpolation were used to compare the effectiveness and accuracy.There are three OK models:spherical model,exponential model,and Gaussian model.Interpolation accuracy was cross-validated by using mean error (ME) and root mean square error (RMSE).The results show that the OK method is superior to other methods.Compared with the spherical function and the Gaussian function,the exponential model performs best,with ME and RMSE being 175.807 3 and -1.126 1,respectively.