CAJ | 학술논문

鉴于地形正负开度对地貌的良好表达且具有分析尺度灵活性这一重要特性，本文提出一种借助地形正负开度及其差值图像阈值分割的黄土地貌沟沿线提取方法。首先，计算DEM的地形正负开度，对正负开度进行差值运算以得到开度差值图；然后，对开度差值图进行阈值处理以得到研究区正负地形空间分布特征；最后，借助数学形态学原理完成对二值化开度差值图正负地形边界———沟沿线的自动提取。试验采用高分辨率DEM数据对陕西洛川塬部分地区进行沟沿线信息提取。结果表明，与其他提取技术方法相比，该方法不仅增强了地貌基本形态特征在沟沿线提取过程中的作用与影响，同时也在一定程度上实现了沟沿线提取的精确化和自动化。
감우지형정부개도대지모적량호표체차구유분석척도령활성저일중요특성，본문제출일충차조지형정부개도급기차치도상역치분할적황토지모구연선제취방법。수선，계산DEM적지형정부개도，대정부개도진행차치운산이득도개도차치도；연후，대개도차치도진행역치처리이득도연구구정부지형공간분포특정；최후，차조수학형태학원리완성대이치화개도차치도정부지형변계———구연선적자동제취。시험채용고분변솔DEM수거대협서락천원부분지구진행구연선신식제취。결과표명，여기타제취기술방법상비，해방법불부증강료지모기본형태특정재구연선제취과정중적작용여영향，동시야재일정정도상실현료구연선제취적정학화화자동화。
This paper presents a new method of loess shoulder line extraction with openness and threshold segmentation .Openness is an angular measurement of the relationship between surface relief and horizontal distance which can be derived from DEM .As it has the outstanding ability of expressing the positive and negative terrain characteristics and the attribute of“analysis‐scale flexibility”,in this study , we developed the idea of loess shoulder line extraction based on the difference of positive and negative openness images and threshould segmentation .Firstly ,we calcul ated the positive and negative openness of our study area based on DEM .Then ,a difference image was generated by the subtraction of positive and negative openness images .Afer that ,it was processed by a threshold segmentation method ,and we analyzed some important spatial distribution characteristics of positive and negative terrain in study area . Finally ,we extracted the shoulder lines semi‐automatically by an edge‐detection method which came from the concept of morphology .Our study area locates in Louchuan ,Shaanxi province , a typical hilly gully region in northwstern China .Considering the effect of the local window size on analysis accuracy and the match of the fitness surface and DEM terrain surface,wechosea5m×5mhigh‐resolution DEM of Luochuan which was purchased from Shaanxi Administration of Surveying ,Mapping and Geoinformation .The result manifested that our method enhanced and guaranteed the accuracy ofthe basic geomorphological characters of study area .