地面坡度对滴灌水分入渗过程的影响

通过土箱模拟滴灌实验,研究了不同地面坡度下滴灌水分运移规律。结果表明,地面各方向湿润半径、滴头下湿润深度和最大湿润深度均与时间呈显著的幂函数关系;随着地面坡度的增大,地面顺坡方向湿润锋推进加快,逆坡方向及滴头处横坡方向湿润锋推进减缓,横坡方向最大湿润宽度也随着坡度的增大而减小;在纵剖面上随着地面坡度的增大,滴头下入渗深度逐渐减小,而最大入渗深度则逐渐增加,最大入渗深度的位置也距滴头越远;地表和纵剖面湿润范围的变化表明,与水平地面相比,整个湿润体随着地面坡度的增大明显向下坡方向偏移,且坡度越大,偏移距离越大,湿润体形状由对称的半椭球形向下坡大而上坡小的梨形变化。

Effect of Ground Slope on Water Infiltration of Drip Irrigation

Ground slope had strong effect on water infiltration in drip irrigation and then affected absorbing water of plant and water use efficiency.The simulated experiment of drip irrigation in soil box was conducted to investigate water movement of drip irrigation on different ground slope.The results showed that wetted radius in different direction on soil surface,wetted depth under emitter and maximum wetted depth presented significant power function relationship with time.With ground slope increasing,movement of wetted front on downward-slope direction accelerated,whereas movement of wetted front on adverse-slope direction and cross-slope direction slow down.The maximum wetted width on cross-slope direction decreased with increase of slope.On the longitudinal section,maximum infiltration depth was increasing and its position was far away from emitter with increasing of ground slope,but infiltration depth under emitter was decreasing.Variation of wetted scope on soil surface and longitudinal section indicated that,compare to horizontal ground,whole wetted body moved obviously toward downslope and excursion distance increased with increase of ground slope.The shape of wetted body changed from symmetrical semiellipsoid to pear shape which was big in downward-slope and small in adverse-slope.