横垄坡面渗流与侵蚀微地貌研究进展

Research Advances of Microtopography Change Caused by Seepage and Soil Erosion in Contour Ridging Systems

横垄具有蓄水保土效益,但垄沟内汇集的雨水会诱发侧渗流产生,加速垄面细沟发育和横垄垮塌,减弱横垄的水土保持作用。因此,垄作系统中侧渗流产生机制及水蚀微地貌演化规律,是横垄水土保持机理研究需要解决的关键问题。综述了近年来横垄坡面土壤渗流特性及模拟、侵蚀微地貌研究等方面国内外研究进展,认为当前研究多集中在土壤质地、垄作结构、降雨特性、下垫面填洼状况对土壤入渗、产流的作用等,但有关横垄蓄水作用对坡面土壤水分运动的影响及其贡献没有定量化;常规仪器所测得的微地貌只能反映该分辨率水平下的地表粗糙形态,不能完全反映坡面形态的真实信息。应加强对横垄坡面土壤水分运动过程模拟,而针对横坡垄作这一耕作措施,需要对其不同侵蚀发育阶段微地貌演化过程进行研究。

Contour ridging is an effective soil conservation practice used on sloping land;but the rainwater collected in the ridges may induce side seepage, accelerate the development of ridge surface rills and the collapse of ridges, and furthermore weaken the role of ridges in water and soil conservation. The generation mechanism of side seepage and the evolution law of water erosion microtopography are the key problems to be solved in the study of soil and water conservation mechanism in ridge farming system. Research progress on the characteristics and simulation of soil seepage and water erosion microtopography on ridge slope in recent years are reviewed. Current research is mainly focused on the effects of soil texture, ridge planting structure, rainfall characteristics, and the filling condition of underlying surface on soil infiltration and runoff generation;the effects of water storage in ridges on soil water movement on the slope have not been quantified yet. The microtopograpy measured by conventional instruments only reflects the surface roughness at specific resolution level, but can’t reflect the true information of slope shape completely. It is necessary to strengthen the simulation of soil water movement process on the cross ridge slope and study the evolution process of microtopography in different erosion development stages.