长白山地丘陵区解冻期农耕地土壤侵蚀特征量化分析

Quantitative Analysis of the Soil Erosion Characteristics in Cultivated Land in Thawing Period in Hilly Area of Changbai Mountain

为防治解冻期土壤侵蚀,以东北长白山地丘陵区典型小流域为研究对象,选取典型农耕地进行实测观测,分析不同坡位、局部坡度、坡向解冻期土壤侵蚀特征,量化土壤水分、温度、剪切力、反射辐射及局部坡度对土壤侵蚀的影响,构建解冻期农耕地土壤侵蚀预测模型。结果表明:解冻期土壤侵蚀从坡上、坡中到坡下依次增大,随局部坡度的增大而增大,但增长趋势减缓,南坡最大而北坡最小,不同坡位、局部坡度和坡向土壤侵蚀均存在显著差异(P<0.05);影响土壤侵蚀的因素从大到小依次为局部坡度、土壤含水率、土壤剪切力、土壤温度和土壤反射辐射;通过逐步回归,构建了基于局部坡度、土壤含水率、土壤剪切力3个因子的解冻期农耕地土壤侵蚀预测模型(R 2=0.903)。研究结果可为解冻期土壤侵蚀防治提供科学依据。

In order to prevent and control soil erosion during the thawing period,two typical small watersheds were taken as the research objects in the Hilly Area of Changbai Mountain in the Northeast Black Soil Region.Soil erosion,soil moisture(ω),soil temperature(T),soil shear stress(τ),soil reflected radiation(J)and local slope gradient(S)were observed during spring thawing period,and their corresponding effects on soil erosion were quantified,then the soil erosion prediction equation was developed.The results showed that soil erosion increased from the upslope,middle slope to the bottom slope;with the increase of the local slope gradients,soil erosion increased,but the increasing trend slowed down gradually;among the different aspects,southern slope had the largest soil erosion,and the northern had the smallest;and the differences were all significant(P<0.05).The factors affecting soil erosion were S,ω,τ,T and J,from large to small,during the thawing period.The prediction equation of soil erosion based on local slope gradient,soil moisture content and soil shear stress was developed(R 2=0.903).This study would provide a scientific basis for soil erosion control during the thawing period.