大理河流域土壤侵蚀空间分布的地貌特征研究  

Study on Topographic Characters of Soil Erosion Spatial Distribution in Dalihe Watershed on Loess Plateau

作　　者：沈中原[1] 李占斌[1,2] 杜中[1] 程圣东[1] 

机构地区：[1]西安理工大学西北水资源与环境生态教育部重点实验室,陕西西安710048 [2]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

出　　处：《水土保持学报》2008年第5期78-81,共4页Journal of Soil and Water Conservation

基　　金：国家“十一五”科技支撑计划(2006BAD09B02);国家重点基础研究发展计划项目(2007CB407206);西安理工大学优秀博士学位论文基金(207-210010)

摘　　要：以GIS为平台,结合第2次遥感调查黄土高原土壤侵蚀数据库,对大理河流域土壤侵蚀空间分布的地貌特征进行了研究。结果表明:水力侵蚀是大理河流域土壤侵蚀的主要形式。各种强度水力侵蚀空间分布的高程特征呈现峰值现象,其中强度以上水力侵蚀面积集中分布于1 240 m高程左右。各种强度水力侵蚀的面积比重,随着坡度的增加呈现先增大后减小的趋势,25°左右存在一个侵蚀临界坡度。临界坡度值随着侵蚀强度的增强而增大。坡向特征呈现双峰现象,其中东北与西南坡向是大理河流域的优势坡向,强度以上水力侵蚀在东北坡向的分布比重大于西南坡向。大理河流域土壤侵蚀存在一个30 m左右临界起伏度。土壤侵蚀强度的变化对起伏度的变化不敏感。此结论为进一步研究流域水土流失动态模拟与区域生态环境长期演变提供了新思路和新角度。Based on geographic information system （GIS） and combined with loess plateau SOil erosion aatabase, the topographic characters of spatial distribution of soil erosion in Dalihe watershed on loess plateau was studied. The results showed that water erosion was the main form of soil erosion in Dalihe watershed. The elevation characteristics of spatial distribution of soil erosion with various intensities exhibits peak phenomenon. The distribution of intensive erosion, highly intensive erosion and serious erosion was concentrated on the region with the altitude about 1 240 meter. The area proportion of soil erosion with various intensities decreased firstly and then increased with the increase of slope. There was a critical slope of erosion at about 25^o. And the critical slope of erosion increased with the increase of soil erosion intensity. The aspect characteristics showed double-peak structure,while northeast and southwest were both the superiority aspects in Dalihe watershed. The area proportion of intensive erosion,highly intensive erosion and serious erosion were bigger in northeast than in southwest. There was a critical relief of erosion at about 30 m. The changes of relief had less effects on the changes of soil erosion intensity. The results in the paper could provide new study idea and new study perspective for further study on the dynamic simulation of watershed soil and water loss and on the long-term evolvement tendency of watershed ecological environment on loess plateau.

关 键 词：黄土高原 土壤侵蚀 空间分布 地貌特征 空间分析 

分 类 号：S157.1[农业科学—土壤学]