永定河典型护岸植被土壤水分入渗特征及影响因素  

Soil Water Infiltration and Influencing Factors of Typical Revetment Vegetation in Yongding River

作　　者：朱美菲 程金花[1,2] ZHU Meifei;CHENG Jinhua(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Key Laboratory of Soil and Water Conservation and Desertification Control,State Forestry Administration,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]国家林业局水土保持与荒漠化防治重点实验室,北京100083

出　　处：《土壤》2023年第5期1129-1137,共9页Soils

基　　金：国家自然科学基金项目(32071839)资助。

摘　　要：为探究永定河岸坡缓冲带不同护岸植被覆盖下土壤水分入渗状况及植被根系对其影响,为区域河岸带生态修复和水资源保护提供参考,选取永定河流域典型护岸植被柳树林、荆条林、狗尾草地为研究对象,通过亮蓝染色法结合Photoshop、Image Pro6.0等图像处理技术,基于分形维数和多指标评价法定量评价了优先流发育程度,并探讨了不同植被根系对优先流的影响。结果表明:①研究区3种植被类型覆盖地土壤均存在水分优先入渗现象,土壤染色面积比随土层深度增加而逐渐减小,柳树林地平均染色面积比(38.32%)最大,为荆条林地和狗尾草地的1.11倍和1.37倍。狗尾草地的长度指数、优先流分数均显著低于柳树林地(P<0.05),3种植被覆盖地基质流深度无显著差异。②以优先流评价指数和分形维数评价优先流发育程度的结果呈一致,为柳树林地>荆条林地>狗尾草地,柳树林地的湿润锋迹线破碎化程度最高,优先流发育最显著。③有机质、非毛管孔隙度和根长密度对水分入渗均具有显著影响,总根长密度、非毛管孔隙度与染色面积比呈显著正相关,≥1 mm根系根长密度、有机质含量与分形维数呈显著正相关。3种植被覆盖地染色面积比和根长密度关系曲线拟合较好。总之,在外界条件相同的情况下,柳树林地水分优先入渗现象最明显;植物根系的径级、密度对优先流的发育具有显著影响,≥1 mm根系越丰富优先流现象越明显,而径级<1 mm的根系主要促进表层土壤水分均匀入渗。In order to study soil water infiltration under different revetment vegetation to provide references for regional riparian ecological restoration and water resources protection,three typical vegetation in the slope vegetation buffer zone of the Yongding River basin,including Willow,Vitex and Setaria were selected,dye morphology were studied by combining bright blue staining method with the software of Photoshop,Image Pro6.0.The development degree of priority flow was quantitatively evaluated based on fractal dimension and multi-index evaluation method,and the influences of different vegetation roots on priority flow was discussed.The results showed that water referential infiltration occurred in the soils under the three vegetation,the ratio of soil stained area(Dc)decreased gradually with the increase of soil depth,average Dc(38.32%)was the largest under Willow,which was 1.11 and 1.37 times of Vitex and Setaria,the length index and preferential flow fraction were significantly lower under Setaria than those of Willow(P<0.05),no significant difference was found in the depth of substrate flow under the three vegetation.The results of the priority flow evaluation index(PFI)and fractal dimension(FD)were consistent in the order of Willow>Vitex>Setaria,the wet front line fragmentation of Willow was the highest,and the priority flow phenomenon was the most obvious.Organic matter,non-capillary porosity and root length density significantly influenced water infiltration,the total root length density and non-capillary porosity were significantly positively correlated with Dc,FD was significantly positively correlated with roots≥1 mm and organic matter,and Dc was well fitted with root length density.In conclusion,under the same external conditions,Willow priority flow degree was greater,the diameter class and density of plant roots significantly influenced the development of preferential flow,and the more abundant roots≥1 mm,the more obvious the preferential flow phenomenon was,while the roots with diameter class<1 mm

关 键 词：优先流 多指标综合评价法 染色示踪 分形维数 根长密度 

分 类 号：S157.1[农业科学—土壤学]