DEM辅助的土壤速效钾及速效磷空间分异研究——以杭埠河流域为例

DEM-based spatial variability of soil available potassium and phosphorus:a case study in Hangbu river watershed

在地理信息系统支持下,运用地统计学,结合DEM数据研究大别山东北坡杭埠河流域土壤表层速效钾和速效磷的空间变异特征,并利用Kriging插值法绘制土壤速效钾和速效磷含量空间分布等值线图。结果表明:该区土壤速效钾和速效磷的半方差函数理论模型分别为指数模型和球状模型,模型块金方差与基台值之比C0/(C0+C)分别在30.5%~31.9%和58.5%~57.2%之间变化,具有中等空间相关性,是由结构性因素和人为活动等随机因素影响共同作用的结果。研究区域内速效钾和速效磷的空间分布大体相同,表现为西南部含量高,东北平原区含量低,沿万佛湖周围含量普遍较低。速效钾与高程的相关系数为0.290 7,速效磷与高程的相关系数为-0.076 8。

The spatial variability of soil available phosphorus and potassium was studied by geostatistics and DEM on a geographic information system. A contour map on the spatial distribution of soil available phosphorus and potassium was drawn by Kriging interpolation method. The result indicated that the theoretical models for semivariogram of soil available phosphorus and potassium in study area were index and spherical models. The ratio of nugget to sill was 30.5 ^- 31.9 for soil available phosphorus, and 58.5%-57.2 % for soil available potassium. The moderate spatial correlation showed that the spatial heterogeneities were mainly produced by structural and manual faetors. The spatial variability map of soil available potassium and phosphorus had the same distribution pattern that higher content appeared in the southwest, lower in the Northeast Plain and generally low in the area around Wanfo Lake. The correlation coefficient between available potassium and the elevation was 0. 290 7. The correlation coefficient between available phosphorus and the elevation was --0. 076 8.