裸露根系分布影响坡面产流产沙特征研究  

Effect of exposed roots distribution on characteristics of runoff and sediment along the slope

作　　者：牟丽敏 周娜娜 冯娅瑛 韩珍 MOU Limin;ZHOU Nana;FENG Yaying;HAN Zhen(College of Forestry,Guizhou University,550025,Guiyang,China)

机构地区：[1]贵州大学林学院,贵阳550025

出　　处：《中国水土保持科学》2025年第1期80-89,共10页Science of Soil and Water Conservation

基　　金：国家自然科学基金项目“喀斯特坡地裸露根系特征及其对地表/地下侵蚀过程的影响”(42467043);贵州省基础研究项目(自然科学)“植物根系出露驱动喀斯特坡面侵蚀动力机制变化研究”(黔科合基础-ZK[2023]一般065)。

摘　　要：坡面植被根系分布复杂。随着侵蚀过程的发生,强烈的径流或泥沙扰动会造成根系裸露。特别是土层浅薄的喀斯特地区,侵蚀引起的根系裸露现象更为常见,而根系裸露后如何影响坡面侵蚀过程研究尚待深入。本研究通过人工模拟冲刷方法测定探究不同裸露根系分布方式(顺坡裸露、横坡裸露、交叉裸露)影响下坡面初始产流时间、产流量以及产沙量特征,并以无裸露根系分布的坡面作为试验对照组。研究结果表明:在不同试验条件下,坡面初始产流时间表现为交叉裸露>裸坡>顺坡裸露>横坡裸露,其中根系交叉裸露坡面产流时间超过5 min,交叉裸露坡面初始产流时间是裸坡的3.78倍、顺坡裸露的5.62倍、横坡裸露的6.33倍;不同试验条件下坡面产流分配主要贡献在地表径流,所占比例均> 80%;在坡面产沙动态过程中,整体呈现出先增大后减小,最后趋于稳定的变化规律,顺坡裸露产沙总量为0.31 kg,是横坡裸露的1.29倍,是交叉裸露的1.38倍,是裸坡的1.41倍。裸露根系的存在改变坡面初始产流时间,产流分配以地表径流为主,加剧坡面产沙过程,且不同裸露根系分布方式的影响程度存在差异。研究结果有助于深化对植物根系影响坡面侵蚀过程机理的认识。[Background]The distribution of vegetation roots on slopes is complex phenomenon.Erosion processes,strong runoff,or sediment disturbances can cause roots to be exposed,and in some cases,may even uproot plants completely,compromising their ability to effectively stabilize the soil.The phenomenon of exposed roots due to soil erosion is prevalent,especially in the Karst areas with shallow soil layer.Although exposed roots play a significant role in calculating erosion rates,their exact impact on the erosion characteristics of karst sloping land remains unclear.This limitation hinders a comprehensive understanding of erosion processes and mechanisms in this area.[Methods]The experiment selected the root systems of representative tree species in the research area,such as acacia and camphor trees,as the research objects.By using an excavation method to obtain coarse roots of 15-20 mm,different distribution patterns of exposed roots on the slope surfaces were established,such as parallel slope arrangement(PSA),transverse slope arrangement(TSA),cross slope arrangement(CSA),and bare slope.The artificial simulated scouring test method was utilized to measure the initial runoff production time,runoff characteristics,and sediment characteristics on the slope surface under varying test conditions.The one-way analysis of variance was used to compare the differences between the data.[Results]The results showed that 1)under different experimental conditions,the initial flow production time of the slopes varied,with the highest initial runoff production time on the slope surface observed in the cross slope arrangement,followed by the transverse slope arrangement,parallel slope arrangement,and bare slope.In the cross slope arrangement,the initial runoff production time exceeded 5 mins,which was 3.78 times longer than that of the bare slope,5.62 times longer than that of the parallel slope arrangement,and 6.33 times longer than that of the transverse slope arrangement.2)The distribution arrangements of exposed roots showed variatio

关 键 词：裸露根系 初始产流 产流分配 坡面产沙 坡面侵蚀 

分 类 号：S157.1[农业科学—土壤学]