沂蒙山区典型县土壤可蚀性K值空间变异研究

Spatial Variability on K Value of Soil Erodibility in Typical County of Yimeng Mountain Area

土壤可蚀性是一个相对概念,在时间、空间等方面呈现异质性特征,选取蒙阴县和沂水县为研究区域,采用EPIC模型中K值计算方法,以地统计学原理为指导,基于Arc GIS地统计模块,探讨了沂蒙山区典型县土壤可蚀性空间分布特征,为区域土壤侵蚀评价提供数据支撑。结果表明:(1)研究区土壤可蚀性K值变化范围为0.1057~0.3776,属中等变异,以中低可蚀性土壤分布最广;在分布最广的粗骨土土类中,石灰岩钙质粗骨土K值最大,为中高可蚀性土壤,存在较大的侵蚀危险性。(2)蒙阴县西北部区域为低可蚀性土壤,中部和东南部为中可蚀性及以上土壤;沂水县土壤主要为中低可蚀性,而南部、西北及东北部存在中高及高可蚀性土壤;两县相接区域土壤为中可蚀性及以上土壤。(3)同一土类而不同土地利用呈现异质性特征,不同土地利用K值大小依次为园地>耕地>林地>草地。(4)随着海拔高度增大,土壤可蚀性K值呈逐渐减小趋势。

Soil erodibility is a relative concept, presenting the heterogeneity in such aspects as time and space. This paper, taking Mengyin County and Yishui County of the Yimeng Mountain area as the study area, using K value calculation method of EPIC model, and ArcGIS statistics module, explored the spatial distribution characteristics of soil erodibility at the county scale in order to provide a basis for soil erosion evaluation. The results showed that： （1） The range of K value of soil erodibility was 0.1057 - 0.3776, belonging to moderate variability, and low and medium erodibility soil was most widely distributed in the study area. And in the most widespread skeleton soil, K value of limestone skeleton soil was the highest and had a big risk of erosion. （2） The soil was at low erodibility level in the northwestern and was at or above medium erodibility level in the central and the southeast region of Mengyin County. The majority soil was at low and middle erodibility levels in Yishui County and existed at the high and high erodibility levels in the south, northwest and northeast parts. The intersection region between Mengyin and Yishui Counties was at or above medium erodihility level. （3） The K value of different land use was decreased in turn in the garden 〉 farmland 〉 forestry 〉 meadow. （4） With the increase of altitude, the K value of soil erodibility decreased gradually.