DEM分辨率对微地形形态的影响  

Effect of DEM Resolution on the Micro Relief

作　　者：魏舟[1] 李光录[1] 任磊[1] 杨晨辉[1] 杨娟[1] 李柏桥 刘馨 

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]勉县水土保持工作站,陕西勉县724200

出　　处：《水土保持研究》2015年第3期105-110,共6页Research of Soil and Water Conservation

基　　金：陕西省水保局重点科技示范项目(20101003);水利部科技推广计划项目(TG1308)

摘　　要：不同的DEM采样间隔能够使地表微地形的概括发生变化,导致微地形观测结果出现差异,该文主要研究不同观测尺度条件下微地形的变化。在深耕、浅耕、裸坡和细沟4种地形条件下,采用三维激光扫描仪获得5,10,20mm的点云数据。通过地理信息相关软件对点云数据加以处理分析,提取不同尺度条件下各类微地形的坡度、坡向、坡度变化率和坡向变化率;通过坡度、坡向定性研究微地形变化与观测尺度之间的相关性,通过对坡度变化率、坡向变化率的研究得出坡度、坡向的变化值域。不同地形条件的微地形在不同观测尺度下变化有明显差异。坡度在8°~15°,15°~25°,45°~60°,60°~90°变化均一;坡向受观测尺度影响主要集中在阳坡和半阳坡;坡度变化率和坡向变化率表明观测尺度越细微地形坡度坡向变化情况越显著,从10,20mm观测尺度下的0~3/3,3~∞两个取值区间逐渐迁移到在5mm尺度条件下的3~∞。Different sampling intervals of DEM can change space surface of micro relief, and lead that the observation of micro relief shows the divergence. This paper examined the change of microtopography based on different scale of observation. In four kinds of topography, i.e. deep ploughing, zero tillage, bare slope, and rill, point cloud data at 5,10,20 mm were acquired using 3D laser scanning. Gradient, slope direction, slope variability and slope aspect variability on different scales were obtained through the analysis on the point cloud data with Geographic Information System software. The interdependency between micro relief change and observation scale was studied with slope gradient and slope aspect. And the scopes of slope gradient and slope aspect change were acquired by studying slope variability and slope aspect variability. The micro topography of different topographic condition under different scales of observation has visible difference. When the slope gradients are 8°~15°, 15°~25°, 45°~60° and 60°~90°, it changes relatively equally~ the slope aspect effect of observation scale concentrates on sunny slope and semi-sunny slope; slope variability and slope aspect variability show that the smaller the observation scale is , the more apparently the slope gradient and slope aspect change, and value with range fromin the observation scale of 10 mm and 20 mm gradually shifts toon the scale of 5 mm.

关 键 词：微地形 坡度 坡向 坡度变化率 坡向变化率 

分 类 号：P951[天文地球—自然地理学]