| 摘要: |
| 【目的】针对雨滴击溅与薄层水流混合侵蚀过程输沙机理研究中存在的问题,研究雨滴击溅对坡面径流输沙的影响。【方法】采用室内人工模拟降雨试验,以土娄土、黄绵土和黑垆土为供试土壤，在不同雨滴直径（直径2.22，2.68和3.04 mm）、不同坡度(0°，2°和4°)和薄层水流厚度（0，2，4和6 mm）条件下，分析单雨滴击溅时，泥沙溅蚀量与水层厚度的关系；多雨滴击溅时，泥沙溅蚀量与薄层水流厚度的关系，分别对二者关系进行拟合；同时，对于多雨滴击溅时，不同薄层水流厚度下黄绵土泥沙溅蚀量和雨滴动能的关系进行了分析。【结果】单雨滴击溅时，泥沙溅蚀量随水层厚度的增加而减少，且雨滴直径越大其扰动水层厚度越大，当雨滴直径由2.22 mm增加到3.04 mm时，平均扰动水层厚度由10 mm增加到14.67 mm。多雨滴击溅时，在相同的坡度（0°～4°），不同土壤和雨滴直径下，随薄层水流厚度的增加，泥沙溅蚀量呈先升后降趋势；当薄层水流厚度相同时，随雨滴直径的增加，泥沙溅蚀量呈增大趋势。当雨滴动能不变时，泥沙溅蚀量随着薄层水流厚度的增加而增大；当薄层水流厚度一定时，泥沙溅蚀量随雨滴动能的增加而增大。【结论】建立了单雨滴击溅和多雨滴击溅条件下扰动水层厚度关与泥沙溅蚀量的关系式。 |
| 关键词: 模拟降雨 薄层水流 混合侵蚀 雨滴动能 雨滴击溅 输沙机理 |
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| 基金项目:国家级大学生创新创业训练计划项目（1210712061） |
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| Rain splash and sheet flow mixed sediment transport mechanism |
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ZHENG Teng-hui,XING Yuan-yuan,HE Kai-xuan,et al
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| Abstract: |
| 【Objective】Effect of raindrop splash on slope runoff and sediment transport was studied in this paper.【Method】In the indoor artificial rainfall simulation, different slopes (0°,2° and 4°),different sheep flow thicknesses (0,2,4 and 6 mm) and different raindrop diameters (2.22,2.68 and 3.04 mm) were tested.The relationships between sediment splash erosion amount and the deep layer of water for single raindrop splashing and between sediment splash erosion amount and sheet flow thickness for multiple raindrop splashing were analyzed and fitted.The relationship of sediment splash erosion amount of yellow soil and raindrop kinetic energy under different sheet flow thicknesses was also analyzed.【Result】For single raindrop splashing,splash amount decreased with the increase of sheet flow thickness, raindrop diameter increased with the increased of disturbance layer thickness,and the average thickness of water resisting disturbance increased from 10 to 14.67 mm when raindrop diameter increased from 2.22 to 3.04 mm.For multiple raindrop splashing,sediment splash erosion amount augmented firstly then decreased as the increased of sheet flow thickness.With same thickness,sediment splash erosion amount increased with the increase of raindrop diameter.When raindrop kinetic energy remained same,sediment splash erosion amount reduced with the increase of shallow flow thickness.When thickness did not change,sediment splash erosion amount increased with the increase of raindrop kinetic energy.【Conclusion】This study established the relationships between single raindrop splash amount and sediment layer thickness as well as between sediment splash erosion amount and multiple raindrops splash amount. |
| Key words: artificial precipitation shallow flow mixed erosion rain kinetic energy raindrop splash sediment transport mechanism |
