摘要
泥石流是藏东南最典型的水土流失类型,也是一种频发的地质灾害。通过对扎木弄沟泥石流发生前和发生后的土壤理化性质和可蚀性进行试验对比,探讨土壤侵蚀潜在发生危险性,以期为区域泥石流防治提供科学理论依据。采取空间代替时间的方法,选取研究区典型未发生泥石流和泥石流后的样地,采取0～20cm土壤,测定团聚体、结构破坏率、基本物理指标、颗粒组成及有机质,用EPIC模型计算可蚀性K值。结果表明:与泥石流发生前对比,泥石流发生后的土壤>0.25mm非水稳性团聚体和水稳性团聚体相比分别降低4.14%和31.57%,结构破坏率相比增加38.16%,有机质含量由253.27g·kg-1降至34.29g·kg-1;泥石流使土壤容重增加,孔隙度和含水率降低,土壤可蚀性K值呈减小趋势;土壤可蚀性K值与黏粒、粉粒呈显著正相关,与砂粒呈显著负相关关系,与有机质含量、团聚体均呈正相关,与容重呈负相关,而与孔隙度呈正相关。泥石流的发生使土壤粗骨化,有机质含量明显下降,不利于团粒结构的形成和稳定,从而会在一定程度上阻碍植被的恢复,进而造成土壤侵蚀发生的潜在危险性增强。
Debris flow is the most typical type of soil erosion in southeastern Tibet,and it is also a frequent geological disaster.In order to lay the foundation for the prevention and control of soil erosion and debris flow,We compared the physical and chemical properties and erodibility of soil before and after debris flow in Zhamunong Gully,Linzhi,Tibet,and explored the potential danger of soil erosion.This study took space instead of time,we selected the typical plots with no debris flow and debris flow and took the soil samples of 0-20 cm to measure aggregates,structural failure rate,basic physical indexes,particle composition and organic matter,and calculated the erodibility K value by EPIC model.The results show that:Compared with that before debris flow,>0.25mm non-water-stable aggregates and water-stable aggregates after debris flow decreased by 4.14% and 31.57% respectively,the structural damage rate increased by 38.16%,and the organic matter content decreased from 253.27g·kg^-1 to 34.29g·kg^-1 after debris flow;The debris flow increased the soil bulk density,the porosity and water content decreased,and the soil erodibility K value decreased.The K value in soil erosion was positively correlated with clay and powder,and negatively correlated with sand.It was positively correlated with organic matter content and aggregate,negatively correlated with bulk density,and positively correlated with porosity.The occurrence of debris flow makes the soil coarse and ossified,and the content of organic matter decreases obviously,which is not conducive to the formation and stability of the aggregate structure,and will hinder the restoration of vegetation to a certain extent,and thus increases the potential danger of soil erosion.
作者
姚甜甜
张鹏
万丹
喻武
张博
YAO Tian-tian;ZHANG Peng;WAN Dan;YU Wu;ZHANG Bo(College of Resources and Environment/Research Center for Alpine and Soil Conservation,Tibet Agriculture and Animal Husbandry College,Linzhi Tibet 860000,China)
出处
《沈阳农业大学学报》
CAS
CSCD
北大核心
2019年第2期245-249,共5页
Journal of Shenyang Agricultural University
基金
国家自然科学基金项目(41661061)
西藏农牧学院-中国农业大学联合基金项目(2017-NY-04)
关键词
泥石流
土壤理化性质
可蚀性K值
debris-flow
soil physical and chemical properties
erodibility K value
