侵蚀黑土容重空间分异与地形和土地利用的关系

以黑土侵蚀和重点治理的典型流域——黑龙江省拜泉县通双小流域为案例,通过田间取样和测定、数字高程模型（DEM）导出、遥感影像（Landsat-7ETM＋）解译分别获得容重、地形因子和土地类型数据。运用经典统计和地统计学方法,结合地理信息系统（GIS）,探讨侵蚀黑土表层土壤容重空间分异与地形和土地利用的关系。结果表明：小流域尺度上,黑土土壤容重变异（14％）和空间自相关性（块金值／基台值。Co／Co＋C=41．18％,变程2402m）均属于中等强度。坡位和土地利用是影响容重变异的最突出因素。地形是控制空间白相关性的主要结构因素。土地垦殖、耕作方式和管理措施等随机因素强烈地影响了土壤容重的空间自相关性,有48．3％的农田耕层土壤容重过大,结构不良。目前黑土小流域的侵蚀治理方式是适合的,也是很成功的。但在保证土壤不再移位的前提下．如何提高土壤的质量和生产力．即培肥土壤是又一严峻的挑战。

Spatial Variation of Soil Bulk Density in Relation to Terrain and Land Use in Eroded of Black Soil Region

A typical catchment named Tongshuang small watershed,which was subjected to drastic erosion before 1980 and was managed subtly after 1980 in black soil region,was chosen as a study area.The data of soil bulk density,topographic factors and land types were obtained by soil sampling and measurements,deriving from DEM and remote sensing image,respectively.Classical statistics and geostatistics analysis methods were used to describe the spatial variability and to explore the correlation of topographic factors and land use with soil bulk density.The classical statistics analysis results indicated that the soil bulk density of study area was moderately variable(C_v=14%).The slope position and land use were the most discriminating influencing factors.The geostatistics analysis showed that soil bulk density had similarly moderate spatial correlations. The spatial correlations were mainly induced by stochastic factors(C_0/C_0 C=41.18%).The effective spatial autocorrelation range was(2 402) m.The control of soil erosion was successful and inspiring.However,of whole farmland,48.3% was worrisome for their surface's soil structure.It will be an impending task to improve soil fertility.