华北冲积平原区土壤剖面质地层次空间分布的三维随机模拟

STOCHASTIC SIMULATION OF THREE-DIMENSIONAL SPATIAL DISTRIBUTION OF SOIL PROFILE TEXTURAL LAYERS IN ALLUVIAL PLAIN,NORTH CHINA

土壤质地层次的空间分布(或土体构型)的复杂变异性是冲积土壤的典型特点之一,定量描述土体构型对于土地利用和溶质运移研究来说极其重要。本研究根据华北冲积平原上一块面积约15km2区域内的139个土壤剖面观测数据,运用转移概率地统计学方法分析了区域内土壤质地层次空间分布的变异特性。结果表明,土壤质地层次的空间分布不是纯随机的,而是具有一定的空间毗邻转移趋势。将本文得到的土壤质地层次空间分布的三维马尔可夫链模型用于指示条件模拟后,最终模拟结果反映了不同质地层次间的交叉协相关关系,所得结果为进一步模拟水分溶质在区域土壤中的运动提供了有力的支持。

Complicated variability of the spatial distribution of soil textural layers is a typical Characteristic of alluvial soil. Quantificational description of soil profile structure is crucial to the study of land use and transport of soil water and solute. Based on observation of 139 soil profiles in a 15 km^2 region in alluvial plain, North China, a transition probability geostatistical model was used to analyze variability of the spatial distribution of soil textural layers. Results indicate that the distribution of soil textural layers is not merely stochastic, but shows a certain tendency of juxtapositional transference. When this model was used in the conditional simulation of indicator kriging method, the final three-dimensional geostatistical realization of soil textural layers spatial distribution reflected the cross correlation between different soil textural layers. The findings may serve as powerful support for further simulation of water movement and solute transport in the regional soil.