晋南旱塬地农田土壤水分动态及预测模拟

Study on Dynamics of Soil Moisture in Dryland of the South of Shanxi Province and Its Simulation Model

通过测定晋南旱塬冬小麦农田的土壤水分,分析了深层土壤水分与表层土壤水分之间的关系。结果表明,0～30 cm土层受降水和土壤蒸发的交互作用强烈,土壤水分变化幅度较大;120 cm以下各层土壤水分直接受外界变化的影响较小,水分运行较慢,土壤水分的变异幅度较小。在研究土壤水分垂直变化规律的基础上,根据Biswas土壤水分估算模式参数的2种情况即d0分别取固定值和任意值时计算的各参数值,对不同土层的土壤水分进行模拟预测,以便为土壤水分的有效利用与动态调控管理提供决策依据。通过比较预测值与实测值的相对误差来检验分析预测模型的精度,结果显示,平均相对误差为10%左右,且0～50 cm的预测效果最佳。

By measuring soil moisture of winter wheat farmland in dryland of the south of Shanxi province,we analyzed the deep soil moisture and the relationship between surface soil moisture.The results show that,for the effection of the strong interaction of between rainfall and soil evaporation,the change of soil moisture in 0 to 30 cm soil layer is maximum.And below 120 cm soil moisture in each layer,is directly affected less by the change and water run slower,less variation range of soil moisture.Based on the research of the vertical change of soil moisture,according to the soil moisture estimation model parameters of two kinds of circumstances,which was put forward by Biswas,simulate and prediction the soil moisture of different soil layer to provide decision-making reference for the effective use of soil moisture and the dynamic regulation of management.Comparing the relative error of the predicted and the measured values,tested the accuracy of prediction model,the results show that the average relative error is about 10%,and 0 to 50 cm forecast effect is best.