降雨类型对褐土横垄坡面土壤侵蚀过程的影响

发布时间：2018-03-02 05:27

本文关键词： 土壤侵蚀径流横坡垄作褐土模拟降雨雨型　出处：《农业工程学报》2017年24期 　论文类型：期刊论文

【摘要】：雨型是影响土壤侵蚀过程的重要因子之一,而影响效应与耕作措施密切相关。目前,雨型对横垄坡面土壤侵蚀过程的影响机制尚不清楚。该文以褐土横垄坡面为研究对象,设计了平均雨强和降雨量相同的4种雨型(增加、减弱、增加-减弱和减弱-增加型),采用可同时调节垄向和坡面坡度的土槽进行模拟降雨,研究各个雨型下不同侵蚀阶段的产流产沙特征。结果表明:雨型间的径流量和侵蚀量在细沟间和细沟侵蚀阶段均差异显著,且差异在细沟阶段体现的更为明显。雨型间径流量的大小顺序为增加-减弱型减弱型减弱-增加型增加型,侵蚀量则为增加-减弱型减弱-增加型减弱型增加型。给定雨强下(30、60或90 mm/h),径流量、径流贡献率和侵蚀量贡献率均随降雨过程中雨强发生时序的延迟而增加,而单位径流侵蚀量呈相反趋势;雨型间给定雨强同一发生时序下的径流量和侵蚀量及其它们对总径流量和总侵蚀量的贡献率均差异显著。4种雨型下,幂函数均能很好的描述细沟间和细沟侵蚀阶段内产沙率与径流率间的关系,且方程中的指数均低于2,但雨型间幂函数方程中的指数存在明显差异。以上研究结果有助于深入理解褐土垄作系统下的土壤侵蚀机理,并为横坡垄作的合理利用提供科学指导。
[Abstract]:Rain type is one of the important factors affecting soil erosion process, and the effect is closely related to tillage measures. At present, the influence mechanism of rain type on soil erosion process on cross ridge slope is not clear. Four kinds of rain patterns (increasing, weakening, increasing, weakening and decreasing increasing) with the same average rain intensity and rainfall were designed. The simulated rainfall was carried out by using soil trough which can adjust the ridge direction and slope gradient at the same time. The characteristics of runoff and sediment yield in different erosion stages under different rain patterns were studied. The results showed that the runoff and erosion amount of different rain types were significantly different in the rill erosion stage and the rill erosion stage. And the difference was more obvious in the rill stage. The order of runoff between rain patterns was increasing-weakening-increasing-increasing. Under a given rainfall intensity, the runoff, runoff contribution and erosion contribution rate increase with the delay of rain intensity. The runoff and erosion amount and their contribution rate to the total runoff and total erosion were significantly different under the same rainfall intensity and rainfall pattern, and the runoff and erosion amount per unit runoff showed a reverse trend, and there were significant differences in the runoff and erosion amount between rain patterns under the same rainfall intensity and their contribution to the total runoff and total erosion. Power function can describe the relationship between sediment yield and runoff rate between gully and rill erosion stage. The indexes in the equation are all lower than 2, but there are obvious differences in the exponents in the power function equation between rain patterns. The above results are helpful to understand the soil erosion mechanism in the mulching system of cinnamon soil, and to provide scientific guidance for the rational utilization of the ridge cropping on the transverse slope.
【作者单位】：山东省水土保持与环境保育重点实验室临沂大学资源环境学院;
【基金】：国家自然科学基金青年项目(41301292) 国家级大学生创新创业训练计划项目(201610452018)
【分类号】：S157.1

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