中文摘要：

[目的]揭示南方红壤区人工径流小区次降雨对径流泥沙作用规律，为区域水土保持工程实践与基础理论研究提供参考。[方法]基于云南摩布小流域3种下垫面（林地、农地、裸地）人工径流小区2013—2015年自然降雨观测资料，采用M-K趋势检验、灰色相关分析及双累积曲线等方法研究了次降雨量、径流量、泥沙量和入渗率的变化趋势及相关关系，以及降雨因子对径流泥沙的影响。[结果]（1）2013--2015年摩布径流小区月降雨均呈先增加后减少的波动性变化趋势，3a降雨量无显著性变化趋势。（2）相同降雨量各下垫面径流小区产流差异显著（P〈0．05），其中林地最小，农地次之，裸地最大；3种下垫面次降雨径流深增长速率大小规律与此相同。（3）次降雨产沙量与降雨量、径流量均存在密切相关关系，相关系数分别为0．67～0．82，0．69～0．85。径流小区产沙能力随雨强增大而增强。相同雨量下，林地产沙能力最小，而裸地累积产沙量增速最大。（4）3个径流小区的入渗率均随降雨量和雨强增大而增大，其中林地入渗率最大，平均入渗率为94．03％；裸地入渗率最小，平均入渗率为86．28％。[结论]与农地和裸地相比，林地不同程度提高了土壤入渗性能，降低了产流量和产沙量。

英文摘要：

[Objective] Effects of rainfall on runoff and sediment in red soil region of Southern China were studied in runoff plots, to provide references for soil and water conservation engineering practice and fundamental research. [Methods] Based on three underlying surfaces （forest, agricultural land, bare land） of runoff plots in Mobu watershed of Yunnan Province, chrono-changes of rainfall, runoff, sediment and infiltration rate were observed from 2013 to 2015. Their relationships were analyzed by means of Mann-Kendall, grey correlation analysis and double cumulative curve, and so on. Meanwhile, effects of rainfall amount on runoff and sediment were studied. [Results] （1） The monthly rainfall during a year showed a fluctuated trend： firstly increased, and then decreased. The rainfall had no significant change among the three years. （2） Under same level of rainfall amount, significant difference in runoff among the three underlying surfacrunoff plots（p〈0. 05）, they ranked as： forest 〉agricultural land 〉 bare land. For runoff depth, it had the same rank. （3） Sediment yield had a strong correlation with rainfall and runoff. The correlative coefficients were 0.67-0.82 and 0.69-0.85 respectively. The sediment yield increased with the increase of rainfall intensity. Under similar rainfall scenario, forest had the minimum sediment, while bare land had the largest one. （4） The infiltration rate increased with the growth of rainfall and rainfall intensity in all three runoff plots. The infiltration rate was the biggest in forest with an average infiltration rate of 94.03% ; the infiltration rate was the smallest in bare land, its infiltration rate was 86.28%. [Conclusion] As compared with agricultural land and bare land, forest plot increased soil infiltration capacity and reduced the runoff and sediment yield to some extent.