涌泉根灌土壤湿润体运移模型

为了探明涌泉根灌土壤入渗湿润体运移的变化规律,以黏壤土为例,在室内选取不同土壤容重、初始含水率、灌水器套筒透水部长度和埋深等4个因素进行试验,研究这些因素对涌泉根灌土壤入渗湿润锋随时间运移关系的影响．结果表明：土壤入渗湿润锋运移速率随土壤容重的增大而减小,随土壤初始含水率的增大而增大,随套筒透水部管长的增长而增大,但不同埋深对灌水器湿润锋的推进速度无显著影响,涌泉根灌土壤入渗湿润体随时间的运移符合幂指数关系,幂指数在水平和垂直向分别为032和02．以此为基础分别建立了湿润锋在水平和垂直向运移距离的预测模型,并建立了包括土壤容重、初始含水率和灌水器套筒透水部长度的综合预测模型．用建立的综合模型对涌泉根灌土壤入渗湿润锋运移距离进行预测,并对预测值与试验值进行了比较后得出,综合模型的预测精度较高．

Prediction model of wetted front migration distance under bubbled-root irrigation

In order to further research the characteristic variation of wetting body in bubbled root irrigation, the following four factors as different soil bulk density, initial soil moisture, the length and burying depth of pervious sleeve of emitter of clay loam soil as an example were studied experimentally indoors to investigate the effects of these factors on wetting body in bubbled root irrigation. The result shows that the velocity of wetted front decreases when the soil bulk density increases and increases when the initial soil moisture and the length of pervious sleeve of emitter increase while the burying depth has little effect on it. There is a power index relationship between wetted front and time and the index is 032 and 02 for horizontal and vertical orientation respectively. Prediction models were built for horizontal and vertical wetted front distance. Comprehensive prediction model with parameters of soil bulk density, initial soil moisture, the length of pervious sleeve of emitter and depth was built. After comparing the predicted and measured data, it is found that comprehensive prediction model has better prediction precision.