连续性与间歇性降雨下土壤结皮与入渗的关系模拟

The Relationship Between Soil Crust and Infiltration Under Simulation Continuous and Intermittent Precipitation

[目的]为探究连续性和间歇性降雨条件下土壤结皮与入渗性能间的变化关系。[方法]选取3种典型耕作层黄土,通过室内模拟降雨试验,分析不同降雨条件下土壤结皮强度和黏结力与入渗性能的关系。[结果](1)入渗性能随连续性降雨历时及间歇性降雨场次的增加而减小;同等降雨历时和降雨强度下,间歇性降雨的减渗效应高于连续性降雨。(2)土壤结皮强度和黏结力随连续性降雨历时和间歇性降雨场次的增加而增加;褐土和黑垆土的入渗性能与结皮强度和黏结力呈显著线性相关(p<0.05),连续性降雨历时越长、间歇性降雨场次的越多,土壤结皮强度、黏结力以及减渗效应越大;沙壤土的入渗性能与结皮强度和黏结力则呈显著的非线性相关(p<0.05)。(3)结皮的MWD和GMD越小,入渗性能越差,减渗效应越大;关联度分析结果显示,间歇性降雨对入渗性能的影响较高。[结论]相同雨强条件下,间歇性降雨下能形成更坚实的结皮,对土壤入渗性能的削弱能力更强。研究结果可为黄土高原防治水土流失、有效利用水资源提供参考依据。

[Objective]This study was aimed at investigating the variation relationship between soil crust and infiltration performance under continuous and intermittent rainfall conditions.[Methods]Three typical cultivated layer loesses were selected,and indoor simulated rainfall experiments were conducted to analyze the relationship between soil crust strength,cohesion,and infiltration performance under different rainfall conditions.[Results](1)The infiltration performance decreased with the increase of continuous rainfall duration and intermittent rainfall events;under the same rainfall duration and intensity,the desilting effect of intermittent rainfall was higher than that of continuous rainfall.(2)Soil crust strength and cohesion increased with the increase of continuous rainfall duration and intermittent rainfall events;the infiltration performance of cinnamon soil and black earth was significantly linearly correlated with crust strength and cohesion(p<0.05).The longer the continuous rainfall duration and the more frequent the intermittent rainfall events,the greater the soil crust strength,cohesion,and desilting effect.The infiltration performance of sandy soil was significantly nonlinearly correlated with crust strength and cohesion(p<0.05).(3)The smaller the MWD and GMD of the crust,the worse the infiltration performance and the greater the desilting effect;furthermore,the correlation analysis results showed that the impact of intermittent rainfall on infiltration performance is higher.[Conclusion]Finally,under the same rainfall intensity,intermittent rainfall can form a more solid crust,which has a stronger weakening effect on soil infiltration performance.This study can provide a reference for the prevention and control of soil and water loss on the Loess Plateau and the effective utilization of water resources.