垄上线源滴灌湿润体特性研究

Study on Characteristics of Wetting Pattern under Linear Source Drip Irrigation with Ridge Culture

在米脂县孟岔试验基地进行大田试验,研究了同一灌水量、不同流量条件下,垄上线源滴灌湿润体特征值的变化规律及滴灌结束后的水分再分布规律。试验结果表明:在线源交汇入渗情况下,滴头处和交汇面处垂直入渗距离与入渗时间均满足良好的幂函数关系。在灌水量为9L的情况下,湿润体沿滴灌管布置方向剖面上的土壤含水率等值线大致以15cm深度为分界线,上层呈现以滴头为中心的椭圆状,而下层则相对平缓。滴灌停止后24h时的湿润体较为稳定,其特征值可以作为线源滴灌灌水量设计的依据,同一灌水量条件下,滴头流量对滴灌停止后24h的湿润体特征值影响并不大。

a series of field experiments were conducted in Mengcha demonstration base in Mizhi,to study the effects of different dripper discharge on the characteristics of wetting body and the course of soil water redistribution under linear source drip irrigation with ridge culture,and the results show that： the vertical infiltration distance of soil wetted front were good power functional relation with infiltration time on the intersection side and the side under the dip emitter. Under the situation that the irrigation volume equals 9 L,the contour map of soil water content,on the profile along the drip irrigation pipe,showed as a series ellipses centered roughly on the drip emitter above the soil layer in 15cm depth,while under 15cm soil layer the contour map became flat. The characteristic values of wetting pattern when 24 hours after the end of the drip irrigation is relatively stable,so they can be used as the basis of irrigation volume for linear drip irrigation system design. It is also found that in the situation of the same irrigation volume,the dripper discharge has little influence on the characteristic values of wetting pattern when 24 hours after the end of the drip irrigation.