Prediction model of wetted front migration distance under bubbled root irrigation
ZHANG Zhi-Tao, WU Pu-Te, CHEN Jun-Ying, ZHU De-Lan, FAN Xiao-Kang
(1.College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; 2.Southern Plains Agricultural Research Center, Agricultural Research Service, USDA, College Station, TX 77845, USA; 3.Department of Biological and Agricultural Engineering, Texas A&M University, College Station, TX 77843, USA; 4.Insititute of Soil and Water Conservation, CAS&MWK, Yangling, Shaanxi 712100, China)
Abstract:In order to further research the characteristic variation of wetting body in bubbledroot 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 bubbledroot 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 032 and 02 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.
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