| Cite this article: | 段凤仪,朱成立,王策,等.灌溉优先流对裂隙分布密度、灌水强度及土壤湿度的响应机理[J].灌溉排水学报,0,():-. |
| DUAN Fengyi,ZHU Chengli,WANG Ce,et al.灌溉优先流对裂隙分布密度、灌水强度及土壤湿度的响应机理[J].灌溉排水学报,0,():-. |
|
| |
|
|
| This article has been：Browse 488Times Download 0Times |
|
|
|
| DOI： |
|
| Mechanisms of Fracture Distribution Density, Irrigation Intensity and Antecedent Water Content on Crack Preferential Flow |
|
DUAN Fengyi1, ZHU Chengli1, WANG Ce1, CHEN Yu2, MA Liang1
|
|
1.Nanjing Hohai University;2.Jiangsu Rural Water Conservancy Science and Technology Development Center
|
| Abstract: |
| 【Objective】To study the mechanism of the effect of initial soil moisture content, fracture distribution density and irrigation intensity on crack preferential flow intensity.【Method】In this paper, a A dual-permeability model for crack preferential flow based on the principle of water volume balance was constructed, and a dye tracing test was carried out for model validation. Furthermore, the above model was used to simulated the crack preferential flow under the rotating combination of fracture distribution density, antecedent water content and irrigation intensity.【Result】The shallow small cracks (average width between0.2 ~ 1.0 cm, average depth between 0.5 ~10 cm) in the test area were not directly related to the development of preferential flow, and the wide and deep cracks (average width above 2 cm, average depth above 50 cm) were the main cause of crack preferential flow; the greater the distribution density of cracks, the greater the matrix flow depth, staining area rate, and irrigation uniformity. The model was remarkably valid in predicting the crack preferential flow (R2 = 0.951, P < 0.01). The simulation results showed that the crack depth largely determined the maximum infiltration depth of preferential flow; Irrigation intensity close to soil saturated hydraulic conductivity could not trigger preferential flow and as the irrigation intensity increased the matrix flow depth and irrigation uniformity decreased, and the degree of preferential flow and maximum infiltration depth are significantly higher. As the antecedent water content of the soil and the density of the fissure distribution increased, the depth of substrate flow and the uniformity of irrigation increased and the degree of preferential flow decreased.【Conclusion】For the field soil with strong shrinkage and rich organic matter content, minimizing irrigation intensity, increasing antecedent soil water content and crack distribution density can effectively suppress crack preferential flow and improve irrigation quality. |
| Key words: crack preferential flow; dual-permeability models; fracture distribution density; antecedent water content; irrigation intensity |
|
|
|
|
|
|
