西南干暖河谷土壤细沟可蚀性垂直地带性差异  

Variation in the Vertical Zonality of Rill Erodibility in Southwest Dry-warm Valley of China

作　　者：周涛 苏正安[1] 何周窈 张小波 杨鸿琨 王俊杰 王晓艺 ZHOU Tao;SU Zheng’an;HE Zhouyao;ZHANG Xiaobo;YANG Hongkun;WANG Junjie;WANG Xiaoyi(Key Laboratory of Mountain Hazards and Earth Surface Processes,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041;University of Chinese Academy of Science,Beijing 100049;Forestry College,Sichuan Agricultural University,Chengdu 611130;Chengdu Water Technical Service Center,Chengdu 610031;College of Environment and Civil Engineering,Chengdu University of Technology,Chengdu 610059;College of Water Conservancy and Hydropower Engineering,Sichuan Agricultural University,Ya’an,Sichuan 625014)

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,中国科学院山地灾害与地表过程重点实验室,成都610041 [2]中国科学院大学,北京100049 [3]四川农业大学林学院,成都611130 [4]成都市水务技术服务中心,成都610031 [5]成都理工大学环境与土木工程学院,成都610059 [6]四川农业大学水利水电学院,四川雅安625014

出　　处：《水土保持学报》2020年第2期56-63,共8页Journal of Soil and Water Conservation

基　　金：国家重点研发计划项目(2017YFC0505102);国家重大基础研究项目(973项目)(2015CB452704);四川省应用基础研究科技计划项目(2018JY0034);四川省重大科技专项(2018SZDZX0034)。

摘　　要：为探究以干暖河谷为基带的西南山地土壤细沟可蚀性垂直地带性差异,选择该区不同垂直带典型土地利用类型(林草地和耕地)下不同土壤类型(红壤、黄壤、棕壤和暗棕壤)为研究对象,利用室内“V”形细沟模拟装置,分别进行6种流量(150,300,450,600,750,900mL/min)和3种水文状态(排水状态、饱和状态和渗流状态)的模拟冲刷试验。结果表明:(1)该区土壤颗粒组成无明显的垂直地带性,林草地的砂粒含量偏高,各土壤的颗粒含量差异在9%以内,所有土壤均为粉质壤土,但有机质差异较大,且随着海拔增加而增加;(2)土壤的细沟可蚀性具有明显的垂直地带性,随海拔升高,林草地土壤可蚀性Kr值逐渐减小,相比于红壤,暗棕壤的Kr值减小幅度平均为47.74%,耕地土壤中黄壤略大于红壤,可能与人为活动强度和土壤熟化程度有关;(3)不同土地利用方式下,林草地土壤Kr值显著大于耕地土壤Kr值,平均增幅为22.63%,这可能与有机质促进土壤抗侵蚀性能的提高有关;(4)不同近地表水文状态下,土壤的细沟可蚀性表现为渗流状态>饱和状态>排水状态,表明随着近地表水文状态变化,尤其是垂直水力梯度的增加会显著导致土壤的细沟可蚀性增大;试验还发现,土壤的临界剪切力仅在不同的水文状态下具有渗流状态>饱和状态>排水状态的规律性,而在不同海拔和土地利用类型之间没有明显的规律性。Typical soils(i.e.,red soil,yellow soil,brown soil and dark brown soil)under different elevations and typical land use types(cultivated land and forestland)were selected to investigate the variations in the vertical zonality of soil erodibility in dry-warm valley of China.AV-shape simulation flume was used to estimate rill erodibility in the erosion process.A series of rill erosion-based scour experiments were conducted,using water discharge of 150,300,450,600,750,900 mL/min and hydrological conditions of drainage,saturation and seepage conditions.Results showed that the composition of soil particle composition had no obvious vertical zonality.The content of sand in forestland soil was relatively high,and the difference of particle composition in each soil was within 9%.All soils were silt loam.However,an obvious difference in soil organic matter appeared among different vertical zones.A vertical zonality of the rill erodibility(K_r value)could be find.As the elevation increased,K_r value of forestland soil decreased,and K_r value of dark brown soil was 47.74%less than that of red soil for forestland.For cultivated land,K_r value of yellow soil was slightly larger than that of the red soil,which could be ascribe to different human activities and soil maturity.Soil K_r of forestland was significantly higher than that of cultivated land with an average increase of 22.63%,which might be relate to the improved anti-erosion ability by soil organic matter.Soil erodibility was highest under seepage condition among different hydrological conditions,and soil erodibilitywas higher under saturation condition than that under drainage treatment.This result indicated that the difference of hydraulic gradients would also affect soil erodibility.Meanwhile,the critical shear stress was also highest under seepage condition among different hydrological conditions,and the critical shear stress was higher under saturation condition than that under drainage treatment.No obvious variation trend appeared among different vertical zonalit

关 键 词：细沟可蚀性 垂直地带性 细沟侵蚀 水文条件 土地利用 

分 类 号：S157.1[农业科学—土壤学]