农田土壤养分交换性镁的空间分布模拟方法比较——以昭阳区为例

采用反距离加权法、径向基函数插值法、克里格法、回归模型法,以云南省昭阳区农田土壤养分采样数据为对象,对全区土壤交换性镁含量进行模拟。结果表明,由于中量元素分布的复杂性,不同模拟方法得到的预测精度不同;反距离加权法强调空间距离权重的影响,未能较好的反应分布规律;径向基函数插值法由于采样点数据具有很大的不确定性,故效果也不理想;克里格法误差最小,精度最高;回归模型法误差较大,但最能反应农田土壤交换性镁分布的地域特征和立体变化特征。

Comparison of Spatial Distribution Simulation Methods for Exchangeable Mg Nutrient in the Farmland Soil——A Case Study of Zhaoyang District

Based on the soil nutrient sample data collected in Zhaoyang District of Zhaotong Municipality,the content of exchangeable magnesium(Mg) of the whole district was simulated by means of the Inverse Distance Weighted(IDW),Radial Basis Function Interpolation,the Ordinary Kring and the Regression Modeling methods.It was indicated by the study that the forecasting accuracy of different simulation methods varied because of the distribution complexity of the intermediate elements.The Inverse Distance Weighted method emphasized the impact of the weight of spatial distance,it could not represent the distribution rule of Mg element very well.Forecast of the Radial Basis Function Interpolation method was not ideal either due to the great uncertainty of the data collected from the sampling points in the study area.The accuracy of the Kriging method was the highest with the least error.The Regression Modeling method created the relatively greater error in the forecast,however it could best reflect the regional characteristic and the vertical change feature of the spatial distribution of exchangeable Mg.