海南儋州耕地土壤有机质空间变异

Spatial Variability of Soil Organic Matter Content in Danzhou City,Hainan Province

以海南省儋州市作为研究区域,综合运用地统计学和地理信息技术,对其耕地土壤的有机质空间变异进行分析。结果表明:儋州耕地土壤有机质平均含量为20.64 g/kg,总体水平为中等偏上;变异系数为48.05%,属于中等变异;其空间变异变程约为16.50 km,C0/(C0+C1)值为37.34%,土壤有机质含量属于中等程度的空间相关性;Kriging插值分析结果可反映土壤有机质含量在空间分布上呈大块状分布,有较强的连续性,其分布变异不显著,以3级含量水平分布范围最广;北部最高,其余区域(南部、东部、中部、西部)逐渐降低。这种空间分布可能与当地的地表形态、地质状况及土地经营利用方式等有关。

Understanding the spatial variation and distribution pattern of soil needed for sustainable development in the region. The spatial variation of organic matter（SOM）content is SOM content in Danzhou was determined using geostatistics and geographic information system（GIS）to provide information for preventing soil degradation. 2597 soil samples （0-20 cm）were collected from the study area. The geostatistical characteristics, spatial trend and range of SOM content were analyzed using the Geostatistical Analyst, ArcGIS 9.0. For all soil samples, the mean of SOM content were 20.64 g/kg, The distribution of SOM content was from the mid to upper level in Danzhou. Statistical analysis showed differences in SOM content among different stratum, landform and land- use type. The average coefficient of variation（CV）of SOM content was 48.05%. The spatial correlation distance（range） was 16.50 km, and the proportion of the semi-variogram model was 37.34%, showed a middle semi-variogram value. The Kriging spatial interpolation showed that SOM decreased gradually from the north to the south, east, west and west in the area. The three levels band of SOM content were distributed in the most widely field. The spatial distribution of SOM content was probably related to variation in stratum, land form and land-use type in Danzhou.