中国农业科学Issue(12)：2365-2373,9.DOI:10.3864/j.issn.0578-1752.2014.12.009
黄土坡耕地地表糙度的空间异质性研究
Spatial Heterogeneity of Loess Tilled Slope Surface Roughness
摘要
Abstract
Objective]The objective of this paper is to reveal the spatial heterogeneity of surface roughness of 4 typical loess tilled slopes during different erosive stages under a micro-scale (2 cm×2 cm) condition.[Method]When slopes with 4 different gradients and tillage measures were prepared (artificial backhoe, artificial digging, contour tillage and straight cultivated slope (check), an erosive rainfall with a rainfall intensity of 60 mm/h was carried out. Soil surface roughness relative elevation data points were taken by a laser scanner and analyzed with both the semivariogram function and fractal dimension models.[Result]The result of classical statistical analysis showed that the loess tillage slope surface roughness has a weak spatial variability. The result of the semivariogram analysis indicated that the loess tilled slope surface roughness had a higher spatial autocorrelation, their spatial autocorrelation scale of surface roughness ranged from 2.02 m to 3.82 m. The spatial heterogeneity caused by the spatial structure characteristic accounted for the greater proportion of the total heterogeneity. The fractal dimension analysis showed that the surface roughness had good fractal features, and it ranged from 1.59 to 1.91. With the increase of gradient, the spatial distribution of slope surface roughness tended to complex, its spatial heterogeneity was stronger. The spatial heterogeneities of the artificial backhoe (AB), artificial digging (AD) and contour tillage (CT) increase in turn within the scope of the small scale, and had a good effect on soil and water conservation.[Conclusion]The main reason for the differences of the spatial heterogeneity of surface roughness is the spatial structural characteristics formed by the integrated interaction of human farming and slope and the artificial cultivation. The space configuration pattern of surface roughness is mainly controlled by slope gradient factor in a smaller scale range, and by the rainfall with its erosion process in a larger scale range. Results of the study will lay a foundation for understanding and quantitative description of the coupling relationship between the surface roughness and erosion, and will also provide a theoretical basis for guiding future tillage practices in the loess sloped regions.关键词
黄土高原/坡耕地/地表糙度/空间异质性/半变异函数/分形维数Key words
Loess Plateau/slope land/surface roughness/spatial heterogeneity/semi-variogram/fractal dimension引用本文复制引用
张莉,张青峰,赵龙山,王健,吴发启..黄土坡耕地地表糙度的空间异质性研究[J].中国农业科学,2014,(12):2365-2373,9.基金项目
国家自然科学基金（41271288、41371273）、陕西省自然科学基金（2011JM5007）、黄土高原土壤侵蚀与旱地农业国家重点实验室基金 （）
