黄土高原土壤可蚀性因子空间分布特征及影响因素

Research on the Spatial Distribution Characteristics and Influencing Factors of Soil Erodibility Factors of the Loess Plateau

为揭示黄土高原地区土壤可蚀性(K)的空间分布特征和影响因素,基于EPIC模型、几何平均粒径模型、Torri模型估算黄土高原地区K,并结合地理探测器比较土壤理化性质、海拔、坡度等要素对K空间分布的影响。结果表明:(1)EPIC模型、几何平均粒径模型、Torri模型估算的黄土高原地区K均值分别为0.036,0.034,0.041 [(t·hm^(2)·h)/(MJ·mm·hm^(2))]。黄土高原以中可蚀性和中高可蚀性的土壤为主,不同模型对K的估算值有显著差异(F=4.460,p<0.01)。(2)黄土高原K有较为显著的空间异质性,东部和西南地区K较高,西北地区K则较低。不同省份的中可蚀性和中高可蚀性面积占比有较大的统计差异。(3)土壤理化性质(砂粒含量、粉粒含量、黏粒含量、碎石含量、容重、酸碱度、阳离子交换量、基本饱和度、交换性盐基、碳酸盐、硫酸盐、可交换性钠盐、导电率)、海拔、坡度、坡向均对K呈现极显著影响(p<0.01)。土壤理化性质对K空间分布的影响强于海拔、坡度、坡向、土地利用因子间交互作用对K的影响大于单个因子。研究结果可为黄土高原土壤水蚀准确防治和土壤改良提供一定的理论依据。

In order to reveal the spatial distribution characteristics and influencing factors of soil erodibility(K-factor)on the Loess Plateau,this research estimated the values of K-factor on the Loess Plateau based on EPIC model,geometric mean grain size model and Torri model.The impacts of soil physical and chemical properties,elevation,slope,and other factors on the spatial distribution of K-factor were compared using geographic detectors.The findings indicated that:(1)The mean values of K-factor on the Loess plateau estimated by EPIC model,geometric mean grain size model,and Torri model were 0.036,0.034 and 0.041,respectively.The dominant soils on the Loess Plateau exhibited medium erodibility and medium-high erodibility,with significant differences in the estimated K-factor values among the models(F=4.460,p<0.01).(2)The K-factor of Loess Plateau showed significant spatial heterogeneity,with higher K-factor in the east and southwest and lower K-factor in the northwest.There were statistical differences in the proportion of medium erodible and medium-high erodible areas among different provinces.(3)Soil physicochemical properties(sand content,silt content,clay content,gravel content,bulk density,pH,cation exchange,basic saturation,exchangeable salt group,carbonate,sulfate,exchangeable sodium salt,electrical conductivity),elevation,slope,and slope direction showed highly significant effect on K-factor(p<0.01).The influence of soil physical and chemical properties on the spatial distribution of K-factor was stronger than those of elevation,slope,and slope direction,and the interaction between factors had more influence on K-factor than individual factors.The study could provide some theoretical basis for the accurate prevention and soil water erosion controlling and soil improvement on the Loess Plateau.