内蒙古地区草地表层土壤容重空间格局分析

本文以内蒙古地区草地表层土壤容重调查测定数据为基础，结合遥感和气候多重数据，进行草地土壤容重与海拔、年均气温、年均降雨、≥10℃积温、湿润度和NDVI等6个生态要素之间的回归分析。根据回归拟合方程，借助ArcGIS平台进行单因素插值，并通过插值预测结果与实测数据的拟合程度进行各因素对土壤容重影响的权重分析，加权叠加并综合插值出内蒙古草地土壤容重1 km×1 km栅格的空间分布图。结果表明：内蒙古地区草地土壤容重平均值为1.45 g·cm^-3，其中温性荒漠类草地的土壤容重最大，为1.58 g·cm^-3，温性草甸草原类土壤容重最小，为1.27 g·cm^-3；空间格局上，草地表层土壤容重自东向西方向呈现由低到高逐渐递增的趋势。综合插值得到的内蒙古草地表层土壤容重空间格局图，通过预测值与实测值之间的复相关性检验，其复相关系数R²=0.6739，均方根误差（RMSE）为0.1424 g·cm^-3，总体偏差为9.77%，平均预测精度达90.23%。综合空间插值结果较好地反映了内蒙古地区土壤容重空间分布情况，与土壤类型和草地类型的分布基本吻合。

Spatial Pattern Analysis on the Soil Bulk Density of Grassland in Inner Mongolia Autonomous Region,China

Based on the measured data of the surface soil bulk density of 198 grassland plots in the region of Inner Mongolia and combined with remote sensing data and multiple meteorological data,this study completed the correlation analysis and regression of the soil bulk density with six ecological elements:altitude, annual average temperature, annual rainfall, ≥10℃accumulated temperature, wettability and NDVI. According to the regression fitting equation and using ArcGIS platform for single factor interpolation, the weight analyses of the 6 factors' influence on the soil bulk were conducted using the interpolation fitting degree of the predicted results and the measured data, and then finished the weighted superposition and integrated interpolation in Inner Mongolia grassland soil bulk density of 1 km×1 km grid space distribution. The results showed that the average soil bulk density of Inner Mongolia grasslands was 1.45 g·cm^-3. Soil bulk density of temperate desert grassland was the largest,1.58 g·cm^-3. The soil bulk density of warm meadow steppe was the minimum, 1.27 g·cm^-3. The surface soil bulk density from east to west showed the tendency of gradual increase on the spatial pattern. Through complex phase test between predicted values and the measured values, the multiple correlation coefficient (R²) of the surface soil bulk density spatial pattern of Inner Mongolia grassland was 0.6739.The root mean square error (RMSE) was 0.1424 g·cm^-3. The overall deviation was 9.77%. The average accuracy was 90.23%. The result of the comprehensive spatial interpolation well reflected the spatial distribution of soil bulk density in the region of Inner Mongolia and it basically agreed with the distribution of soil type and grass type.