不同降雨强度下土壤结皮强度对侵蚀的影响

为定量分析土壤结皮对坡面侵蚀的影响,该文选择塿土、黄绵土、黑垆土和黄墡土4类土壤,分析其在3种雨强（60、90、120 mm/h）下的结皮强度变化规律。结果表明,当土壤含水率高于30%时,不同降雨强度下结皮强度差异不显著（P〉0.05）,当含水率小于30%时,结皮强度随降雨强度增大而增强。以杨凌塿土10°坡面为例,进行坡面人工模拟降雨试验,分析计算不同强度结皮坡面的侵蚀产沙、径流剪切力、阻力系数以及流速,结果表明：结皮对坡面产流的影响并不显著,但其存在有效地减少坡面的侵蚀产沙量。结皮存在能有效地减少坡面产沙量,无结皮坡面的产沙量是结皮坡面产沙量的1.24-8.72倍。相同降雨条件下,结皮强度越...

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Bibliographic Details
Published in农业工程学报 Vol. 33; no. 8; pp. 141 - 146
Main Author 路培 王林华 吴发启
Format Journal Article
LanguageChinese
Published 西北农林科技大学水土保持研究所,杨凌,712100%西北农林科技大学资源环境学院,杨凌,712100 2017
Subjects
侵蚀
土壤
径流功率
流速
流量
结皮强度
阻力系数
侵蚀
流量
阻力系数
径流功率
resistance coefficient
flow rate
土壤
stream power
流速
结皮强度
erosion
flow velocity
soils
crust strength
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ISSN1002-6819
DOI10.11975/j.issn.1002-6819.2017.08.019

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Summary:为定量分析土壤结皮对坡面侵蚀的影响,该文选择塿土、黄绵土、黑垆土和黄墡土4类土壤,分析其在3种雨强（60、90、120 mm/h）下的结皮强度变化规律。结果表明,当土壤含水率高于30%时,不同降雨强度下结皮强度差异不显著（P〉0.05）,当含水率小于30%时,结皮强度随降雨强度增大而增强。以杨凌塿土10°坡面为例,进行坡面人工模拟降雨试验,分析计算不同强度结皮坡面的侵蚀产沙、径流剪切力、阻力系数以及流速,结果表明：结皮对坡面产流的影响并不显著,但其存在有效地减少坡面的侵蚀产沙量。结皮存在能有效地减少坡面产沙量,无结皮坡面的产沙量是结皮坡面产沙量的1.24-8.72倍。相同降雨条件下,结皮强度越大,其产沙量越小。进一步通过灰色关联分析得出：随着坡面结皮强度增加,水流功率对坡面侵蚀的作用效益不断减小,而阻力系数的作用效益增加,即水流增加产沙的正效应不断减弱;另一方面,结皮强度增大使得坡面土壤抗蚀性增强,因此,结皮强度越大,坡面侵蚀量将大幅度减少。研究可为准确有效预报坡面土壤侵蚀提供重要依据。
Bibliography:11-2047/S
flow rate; erosion; soils; crust strength; stream power; resistance coefficient; flow velocity
Soil crust plays an important role in rainfall,runoff and erosion process.When it comes to the present situation,most studies analyze the impact mechanism of soil erosion on the existence of soil surface crust,through comparison analysis of sediment yield,runoff producing and characteristic of hydrodynamic under the crust and no crust slope.However,limited studies report on the characteristic of soil sediment yield,runoff produced and the rule of feature variation for hydrodynamic,also,no quantitative evaluation about the hydraulics parameter＇s influence on sediment yield.Therefore,in our research,according to crust strength variation and hydrodynamic characteristic under different crust strength,we conducted quantitative analysis on the impact of crust on slope erosion,and through comparison analysis for characteristic of slope sediment yield,under different crust intensities.We further analyzed the change
ISSN:1002-6819
DOI:10.11975/j.issn.1002-6819.2017.08.019