东北典型黑土区剖面粒径分布特征及其可蚀性研究

为了更好的了解黑土区土壤剖面粒径分布以及可蚀性因子特征,本研究以东北典型黑土区鹤北流域为研究区,利用沉降法对不同土地利用方式下土层表面至母质的土壤样品进行粒径分布规律研究,并基于粒径及有机碳分布特征,计算了土样的可蚀性K值,最后对土壤可蚀因子K与WEPP模型中土壤的细沟间侵蚀因子(Inter- rill Erodibility)K_i、细沟侵蚀因子(Rill Erodibility)K_r和临界剪切力因子(Critical Shear)Tc进行相关分析。结果表明:(1)不同剖面下土壤粘粒含量逐层变化不大。而粉粒含量呈现出随土层深度增加而含量减少,砂粒呈现出随土层深度增加而含量增大;(2)除人工林外,其余6个剖面土壤可蚀性因子K值均表现出随土层深度增加而含量增大的趋势;(3)对农地剖面土样分析发现,可蚀性因子K值与细沟侵蚀因子K_r呈极显著正相关,与临界剪切力因子Tc呈极显著负相关,而与细沟间侵蚀因子K_i的正相关性略有降低。

Study on Particle Distribution and Its Erodibility in Typical Black Soil Area of Northeast China

Soil erodibility serves as a major parameter for soil erosion prediction and land use planning,re- flects the sensitivity of soil during the erosion process.The paper focused on the black soil in northeast Chi- na,studied the soil particle distribution under different land use,and calculated the soil erodibility using the empirical formula.And then the correlation analysis between soil erodibility and interrill erodibility,rill erodibility,critical shear were carried in order to apply predicted models well.The results show:(1)The change of soil clay content in every layer is not obvious,and along with the soil layer increasing,the silt con- tent reduces but the sand content increases;(2) Expect for the artificial forest,the soil erodibility of the oth- ers land use profile,presents the enhanced trend along with the increasing soil depth;(3)For cropland,the soil erodibility (K) are significantly correlated with the rill erodibility (K_r) and the critical shear (T_c),but the correlation between soil erodibility (K) and interrill erodibility (K_i) is reduced.