基于DEM的黄土塬坡地形特征量化分析研究  

Quantitative analysis of topographic features of Loess Tableland slopes based on DEM

作　　者：李凡 周毅 陈荣 刘畅 李颖 Li Fan;Zhou Yi;Chen Rong;Liu Chang;Li Ying(School of Geography and Tourism,Shaanxi Normal University,Xi'an 710119,Shaanxi,China)

机构地区：[1]陕西师范大学地理科学与旅游学院,陕西西安710119

出　　处：《地理科学》2023年第5期932-942,共11页Scientia Geographica Sinica

基　　金：国家自然科学基金项目(41871288,41930102);中央高校基本科研业务费专项资金项目(GK202003064);陕西师范大学地理科学与旅游学院研究生创新创业项目(1105010008)资助。

摘　　要：系统梳理并界定了塬坡的概念,基于5 m分辨率DEM及0.6 m分辨率快鸟影像,以塬坡为主体,构建地形统计特征、空间展布特征和侵蚀发育特征指标体系,深入分析黄土塬区的地形特征,量化塬区小流域及其内部各级子流域的侵蚀发育程度。结果显示:①塬坡在7个流域中面积占比约10%~35%,地形统计特征表明侵蚀程度和粗糙度等自塬面到沟谷逐渐加剧;②空间展布特征说明塬坡是沟坡系统中最为复杂的地形单元,塬面对塬坡的邻接性较沟谷对塬坡的邻接性弱;③侵蚀指标是塬区小流域侵蚀发育的重要指征,其揭示了流域内部的侵蚀分异规律:侵蚀程度随子流域级别增大而加剧,侵蚀程度越严重的流域,其内部子流域的侵蚀程度也越严重。各侵蚀指标的相关性随子流域级别增加而增强,在0.01置信水平下,侵蚀指标间的最低相关性由0.33提高至0.80。In this article,the concept of plateau slope is systematically sorted out and defined.Based on 5 m resolution DEM and 0.6 m resolution Quickbird images,Taking the tableland slope as the main body,this study constructs the index system of topographic statistical characteristics,spatial distribution characteristics and erosion development characteristics,deeply analyzes the topographic characteristics of the Loess Tableland,and quantifies the erosion development degree of small watersheds and their internal sub watersheds at all levels.The results show that:1)The area of plateau slope accounts for about 10%-35%in the seven watersheds,and the topographic statistical characteristics show that the erosion degree and roughness gradually intensify from the tableland to the valley;2)The spatial distribution characteristics show that the tableland slope is the most complex topographic unit in the gully slope system,and the adjacency of tableland to tableland slope is weaker than that of gully to tableland slope;3)Erosion index is an important indicator of erosion development in small watersheds in the tableland area,which reveals the law of erosion differentiation within the watershed:The degree of erosion intensifies with the increase of sub watershed level,and the more serious the degree of erosion of the watershed,the more serious the degree of erosion of the internal sub watershed.The correlation of each erosion index increases with the increase of sub watershed level.At the confidence level of 0.01,the minimum correlation between erosion indexes increases from 0.33 to 0.80.

关 键 词：黄土塬区 塬坡 塬边线 沟沿线 塬面 沟谷 

分 类 号：S157.1[农业科学—土壤学]