论文部分内容阅读
降雨雨型对土壤侵蚀过程有重要的影响,也是当前土壤侵蚀研究的热点之一。通过野外原位人工模拟降雨试验,设计了次降雨中平均降雨强度、总降雨量相同的4种不同降雨雨型(均匀型:降雨强度为60mm/h;峰值型:降雨强度分布为30-90-60mm/h;延迟型:降雨强度分布为60-30-90mm/h;减弱型:降雨强度分布为90-60-30mm/h),研究降雨雨型变化对东北黑土区坡耕地土壤侵蚀的影响。结果表明:各雨型条件下休闲坡耕地径流总量的大小顺序为延迟型>减弱性>均匀型>峰值型,而土壤侵蚀总量的大小顺序为减弱型>均匀型>延迟型>峰值型。延迟型雨型的坡面径流总量是其它雨型的1.02~1.45倍,减弱型降雨的侵蚀总量分别是均匀型、延迟型和峰值型的1.03、1.36和2.68倍。同一雨强在不同降雨雨型中出现的位置不同,其产生的坡面径流量和侵蚀量对坡面总径流量、总侵蚀量的贡献率也不同,分布在降雨雨型起始位置的雨强对坡面径流量的贡献率最小;除30mm/h降雨强度外,分布在降雨雨型起始位置的雨强对坡面侵蚀的贡献率最大。研究还发现,试验设计中减弱型降雨雨型与东北黑土区夏季主要侵蚀雨型特点类似,是造成东北黑土区坡耕地土壤侵蚀相对严重的主要雨型。
Rainfall type has an important impact on the process of soil erosion, and is also one of the hot spots in current research on soil erosion. Four kinds of rainfall types (average type: rainfall intensity 60 mm / h) and peak type (rainfall intensity distribution 30-90) were designed by simulating in-situ artificial simulated rainfall experiment. -60mm / h; delayed type: rainfall intensity distribution of 60-30-90mm / h; weakened type: rainfall intensity distribution of 90-60-30mm / h), the study of rainfall-type changes on the black soil area of northeast slope soil erosion influences. The results showed that the order of total runoff of recreational sloping farmland was in the order of delay type> weakening degree> uniform type> peak type under all rainfall types, while the order of total soil erosion was decreasing type> uniform type> delayed type> peak type . The total amount of runoff on delayed type rainfall was 1.02-1.45 times that of other types of rainfall, and the total amount of erosion on weakened rainfall was 1.03, 1.36 and 2.68 times that of homogeneous, delayed and peaked types, respectively. The same rainfall intensity appeared in different rainfall type in different positions, and its contribution of slope runoff and erosion to slope total runoff and total erosion were also different. Rainfall was distributed in the beginning of the rainfall The contribution of rainfall intensity to slope runoff is the smallest. Rainfall intensity at the beginning of rainfall type contributes the most to slope erosion except rainfall intensity of 30 mm / h. The study also found that the weakened rainfall type in the experimental design is similar to the main erosion type in summer in the black soil region of northeastern China, and is the main type of rainfall that causes relatively serious soil erosion on sloping farmland in the black soil region of Northeast China.