Simulation study on the effects of dripper spacing on soil water infiltration conditions under surface drip irrigation with two point source emitter | 滴头间距对双点源交汇入渗影响的模拟研究

Chinese. 研究滴头间距对双点源滴灌土壤水分入渗的影响。应用HYDRUS 3D软件，在滴头间距分别为10，20，30和40 cm时，对湿润峰交汇时间、交汇面土壤含水量、湿润峰运移速率和湿润体的形状变化进行模拟研究，并进行试验验证。湿润峰交汇时间随着滴头间距的增大呈指数级增加，湿润峰运移速率与滴头间距之间呈幂函数关系；随着滴头间距的增加，湿润体形状依次从1个近似半球体向近似半药囊形、半花生壳形及2个分离的近似半球体转变，湿润体内高含水量区域也从2个逐渐转化为1个。以土壤剖面含水量、湿润峰运移距离及总入渗量为指标进行验证试验，结果表明，土壤含水量、湿润峰运移距离及总入渗量的模拟值与实测值均具有较好的一致性。滴头间距对双点源滴灌土壤水分入渗影响显著，土壤水分三维数值模拟模型能较准确地反映双点源入渗条件下粘壤土的水分运动规律。

English. Simulation study was done on the effects of dripper spacing on soil water infiltration conditions under surface drip irrigation with two point source emitter. Using HYDRUS 3D software, choosing four kinds of dripper spacings, 10, 20, 30 and 40 cm separately, a simulating study on the soil water content of intersection surface, transport velocity of wetting front and shape change of wetted volume was carried out and the simulation results were tested with field demonstration. The time for geomagnetic crossing showed exponential function of increase and migration velocity of wetted volume-showed power function of increase with dripper spacing adding. Shape of wetted volume changed successively from an approximate hemispheroid to an approximate hemi anther sac, an approximate hemi peanut shell and two approximate hemispheroid. High moisture content regions in wetted volume changed to one from two. And the model by the measurement of soil moisture content, migration distance of water front, and cumulative infiltration in laboratory test was verified. The results showed that the simulation results agreed well with the measurement values. The effects of dripper spacing on soil water infiltration conditions under surface drip irrigation with two point-source emitter is remarkable. The three-dimensionalmodel of establishment can reflect the soil water movement of clay loam conditions under surface drip irrigation accurately.