摘要
[目的]研究永定河平原地区的优先流现象,解析其形态特征和发育程度,明确影响优先流的主要因素,为该区域淡水资源保护以及生态环境恢复提供理论依据。[方法]以3种典型植被柳树、荆条和狗尾草为对象,在25 mm入渗水量下(大雨)通过野外亮蓝染色示踪试验获取原始土样和染色剖面图像,使用图像处理技术解析水分和溶质在土壤中下渗的形态规律,结合相关性分析和主成成分分析法研究不同土壤因子对优先流产生和发育的响应。[结果](1)柳树、荆条和狗尾草土壤优先流分别集中在10—40 cm处、10—40 cm处和10—30 cm处,最大染色深度分别为40.0 cm,44.8 cm,31.5 cm。不同植被类型垂直剖面上显示出染色面积比随土层深度的增加而下降。(2)优先流发育程度为柳树样地>荆条样地>狗尾草样地。柳树样地和狗尾草样地的染色面积比和长度指数差异显著(p<0.05),荆条样地与其他2种植被差异均不显著(p>0.05)。(3)黏粒、砂粒、粉粒含量对方差变异性的贡献率为24.824%,根重密度和有机质含量对方差变异性的贡献率为46.312%。[结论]永定河平原南部3种典型植被中柳树样地最早发生土壤优先流现象,形成优先流染色形态分化程度最高,优先流现象最明显,而狗尾草样地最不明显。随着入渗水量的增加,土壤水分运动表现出整体下移,加深了土壤水流形态分化界面深度,即0—20 cm土层染色形态表现为相对稳定。土壤机械组成与径级小于5 mm根系是影响优先流产生发育的重要因素,由于各样地中植被的生长发育状态不同,因此对土壤优先流的影响程度也不尽相同,存在一定的差异性。
[Objective]The aims of this study are to examine the preferential flow phenomenon in the Yongding River Plain,to analyze its morphological characteristics and development degree,to identify the main factors affecting preferential flow,and provide a theoretical basis for the protection of freshwater resources and the restoration of ecological environment in the region.[Methods]Willow,wattle and Setaria viridis of three typical vegetation were taken as objects.The original soil samples and dyed profile images were obtained by field brilliant blue dye tracing test under 25 mm infiltration water(heavy rain).Image processing technology was used to analyze the morphological rule of water and solute infiltration in soil,and combined correlation analysis and principal component analysis were used to study the response of different soil factors to the generation and development of preferential flow.[Results](1)The preferential flow of the willow,Jing,and dogtail soil concentrated at 10—40 cm,10—40 cm,and 10—30 cm,respectively.The maximum chromosome depth was 40.0 cm,44.8 cm,and 31.5 cm.Different vegetation types of vertical section showed that the chromosomal area decreased compared with the depth of the soil layer.(2)The degree of preferential development was a willow-like land>ine-like>dogtail-like land.The differential ratio and length index of the chromosomal area of the willow-like land were significantly different(p<0.05),and the differences between the two planting of the neither of the two planting of the tattoo(p>0.05).(3)The contribution rate of the content of the other party′s variant was 24.824%,and the contribution rate of root weight density and organic content was 46.312%.[Conclusion]Among the three typical vegetation in the south of the Yongding River Plain,the first willow-sample of soil preferential flow occurred,forming the highest degree of preferential chromatization.The phenomenon of preferential flow was the most obvious,while the dogtail-like land was the least obvious.With the increase of
作者
史德威
程金花
李明峰
Shi Dewei;Cheng Jinhua;Li Mingfeng(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)
出处
《水土保持研究》
CSCD
北大核心
2024年第1期232-240,共9页
Research of Soil and Water Conservation
基金
国家自然科学基金项目“喀斯特地区土石二元结构下优先流对坡面水文过程的影响”(32071839)。
关键词
永定河
优先流
亮蓝染色示踪法
主成分分析
Yongding River
preferential flow
bright blue dye tracing method
principal component analysis
