坡面水蚀过程中地表糙度的空间异质性研究  

Study on the Spatial Heterogeneity of Soil Surface Roughness during the Course of Water Erosion

作　　者：张莉[1] 张青峰[1,2] 徐健[3] 张翔[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100 [3]中国石油长庆油田分公司,西安710018

出　　处：《水土保持研究》2014年第2期6-10,16,共6页Research of Soil and Water Conservation

基　　金：陕西省自然科学基金项目(2011JM5007);国家自然科学基金项目"黄土坡耕地地表糙度对产汇流的影响研究"(41271288)

摘　　要：地表糙度是影响土壤侵蚀过程的重要因子之一,也是土壤侵蚀学科领域研究的热点问题,准确把握水蚀过程中地表糙度的空间异质性特征,对进一步理解土壤侵蚀过程具有重要意义。该文以黄土高原人工锄耕(AB)坡面地表糙度为研究对象,采用地统计学和GIS技术相结合的方法研究了微尺度(2cm×2cm)下地表糙度由雨前(BR)→溅蚀(SpE)→面蚀(ShE)→细沟侵蚀(RE)演化过程中的空间异质性特征。结果表明:地表糙度在各侵蚀阶段均呈弱变异性;半方差函数理论模型分析表明雨前(BR)、溅蚀(SpE)阶段符合指数模型,面蚀(ShE)阶段符合球状模型,细沟侵蚀(RE)阶段符合高斯模型;从空间结构特征来看,各侵蚀阶段均具有中等程度的空间自相关性,空间异质性受随机性因素和结构性因素共同作用,其自相关距分别为0.46m,0.28m,1.29m,1.04m;分形维数分析表明不同水蚀过程中地表糙度的空间变异主要发生在较小尺度上。研究结果可为进一步揭示水蚀过程中地表糙度与土壤侵蚀的相互耦合关系奠定基础。Surface roughness is one of the most important factors affecting soil erosion process, and is also the hotspot in research filed of soil erosion. Exactly grasping the spatial heterogeneity of surface roughness in water erosion process is of significance for further understanding the process of soil erosion. This paper took the surface roughness of artificial backhoe cultivated in loess plateau as research obiects, analyzed the spatial heterogeneity of surface roughness during the development of soil erosion from the stages of before rain （BR）, splash erosion （SpE）, sheet erosion （SHE） to rill erosion （RE） by the method of geostatistics and Geographical Information System （GIS） technique under the micro-scale （2 cm 5〈 2 cm） conditions. The results showed that the surface roughness at all stages of soil erosion presented a weak variation. Analysis of variance of theoretical variogram models showed that before rain （BR） and splash erosion （SpE） followed exponential model, sheet erosion （SHE） followed spherical model, and rill erosion （RE） followed Gaussian model. In terms of spatial structure, each stage of soil erosion all showed moderate spatial autocorrelation. The spatial heterogeneity was resulted from both structural factors and random factors. The autocorrelation distance of the stage of before rain （BR）, splash erosion （SpE）, sheet erosion （SHE） and rill erosion were 0.46 m,0.28 m,1.29 m and 1.04 m, respectively. Fractal dimension analysis showed that the spatial variability of surface roughness in the different process of water erosion mainly occurred on the smaller scales.The results can offer a foundation for revealing the coupling relationship between surface roughness and soil erosion in the process of water erosion.

关 键 词：地表糙度 空间异质性 GIS 地统计学 分形 

分 类 号：S157[农业科学—土壤学]