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在不同坡度(15°、20°、25°)和降雨强度(1.5mm/min和2.0mm/min)条件下,利用室内模拟降雨试验,研究了杨凌塿土和安塞黄绵土的坡面细沟发育过程、形态特征及水沙关系。结果表明,不同降雨强度和坡度下,塿土坡面的细沟发育规律基本一致,主要由沿坡面方向呈线状分布的跌坎链相互连通而成,表现为沟头溯源侵蚀和沟道下切侵蚀,细沟宽深比随雨强及坡度增加而变小,细沟密度则随之而增加;黄绵土的跌坎形状为长条状,细沟主要由单个跌坎发育而成,发育过程中溯源侵蚀和边壁崩塌现象更为明显,细沟的宽深比较大。相比黄绵土,塿土的产流和达到稳定径流量的速度较快,相同降雨强度条件下,不同坡度间径流量的差异性较小;不同降雨强度和坡度条件下,塿土的含沙量变化过程较为一致,最终会趋于一个稳定值,黄绵土含沙量的变化过程较为复杂。另外,两种土壤从含沙量开始较快增加至达到最高值的时间段与其细沟形成及发育的时间段大体吻合,相比之下塿土更易发生细沟侵蚀。
Under the condition of different slope (15 °, 20 °, 25 °) and rainfall intensity (1.5mm / min and 2.0mm / min), simulated indoor rainfalls were used to study the characteristics of slope of Yangling loess and Ansai loess Development process, morphological characteristics and the relationship between water and sediment. The results show that under different rainfall intensities and slopes, the rule of rill development is basically the same on the slopes of slopes, which are mainly formed by the interconnection of cricket chains distributed linearly along the slope direction, Undercutting and erosion, the width-to-depth ratio of the rills becomes smaller with the increase of rain intensity and slope, and the density of the rills increases accordingly. The shape of the fallen ridge of the loessial soil is strip-shaped, and the rill is mainly developed from a single depression. In the traceability of erosion and the collapse of the side walls, the width and the depth of the rill are relatively large. Compared with that of loessial soil and loam soil, the runoff of loess soil and the speed of stable runoff were faster. The difference of inter-surface runoff was smaller under the same rainfall intensity. Under different rainfall intensities and slope conditions, The process of change is more consistent and eventually tends to a stable value. The process of sediment concentration in loessial soil is more complicated. In addition, the periods of rapid increase of both soils from their initial sediment concentration to their maximum values generally coincided with the period of development and development of the rill, which in turn was more prone to rill erosion.