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运用马尔可夫过程的理论 ,建立了土壤非饱和流条件下 ,模拟硝态氮通过土层运移的随机模型 .模型把时间可变系统假设为由紧密相连的时间均质情况相接而成 ,使得运用马尔可夫过程成为可能 ,在给定土壤水流量及汇源项转移强度的土壤层次中 ,给出了硝态氮溶质的统计分布 .模型将随机过程与确定性过程相结合 ,在计算各土层间的转移概率时考虑了硝态氮的作物吸收、淋洗、硝化和反硝化等主要过程 ,并用相关函数修正 N素转化关系 .在褐土农田土壤非饱和流条件下 ,用微区试验对该模型运行效果进行了验证 ,结果显示模拟计算值与实测值之间吻合性较好 ,说明模型可以用于相似类型区 ,预测和评价土壤 -作物系统中硝态氮溶质的运移行为 .
Using stochastic Markov process theory, a stochastic model was established to simulate the migration of nitrate nitrogen through soil layers under the condition of unsaturated soil flow.The model assumes that the time-varying system is connected by close time homogeneity , Making it possible to use the Markov process, giving a statistical distribution of nitrate nitrogen solutes in a given soil water flow and the sink strength of the Huiyuan project. The model combines a stochastic process with a deterministic process, The main processes such as crop uptake, washing, nitrification and denitrification of nitrate nitrogen were considered in the transition probability between soil layers, and the correlation function was used to correct the N transformation.Under the unsaturated soil flow in the cinnamon soil, The experimental results show that the agreement between simulated and measured values is good, which indicates that the model can be used in similar types of areas to predict and evaluate nitrate transport in soil-crop system For