基于BEMD分解的地貌分类研究  

Geomorphological Classification Research based on BEMD Decomposition

作　　者：顾文亚 孟祥瑞 朱晓晨 邱新法[2] GU Wenya;MENG Xiangrui;ZHU Xiaochen;QIU Xinfa(School of Binjiang,Nanjing University of Information Science&Technology,Nanjing 210044,China;School of Applied Meteorology,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]南京信息工程大学滨江学院,南京210044 [2]南京信息工程大学应用气象学院,南京210044

出　　处：《地球信息科学学报》2020年第3期464-473,共10页Journal of Geo-information Science

基　　金：江苏省普通高校研究生科研创新计划项目(KYLX_0850);国家自然科学基金项目(41805049);滨江学院校级课题(2019bjyng005).

摘　　要：地貌是指地势高低起伏的变化,即地表的形态。地貌划分对气温、降水、太阳辐照等诸多应用领域都有着重要作用。本文选择空间分辨率为90 m的福建省的数字高程模型(DEM)数据作为地理信号,运用二维经验模态分解(BEMD)进行分解处理,得到多个具有不同尺度、不同物理意义的本征模函数(BIMF1-BIMF3)以及对应余量ORIG。这些BIMF分量对应不同尺度的微观地形,ORIG余量表现为该研究区的地貌分布趋势,体现了平原、丘陵与山地的大致分布区域。运用变点分析法确定最佳计算单元,利用地形起伏度对各个信号区域进行一级分类,依据绝对高度进行二级分类,最后将一级分类与二级分类相结合,实现对地形的分类,这一分类过程体现了研究地区地貌组合复杂的特征。结果表明:①叠加BIMF分量,提取出分量和大于74 m的区域为高频信号区域。该区域以小起伏度的低山为主,并伴随有丘陵和小起伏度中山。②ORIG余量中余量高度小于等于340 m的区域,去除其中包含的高频信号区域后为低频信号区域,该区域以平原、丘陵为主。③剩余区域定义为中频信号区域,该区域的地貌以平丘陵和小起伏的山地为主。研究成果表明福建地貌可分为7种主要类型:低频平原,低频丘陵,中频丘陵,高频丘陵,中频小起伏低山,高频小起伏低山,高频小起伏中山。Geomorphology refers to the ups and downs of the terrain, that is, the shape of the surface. Geomorphological classification plays an important role in many application fields such as temperature, precipitation and solar irradiation. In this paper, the Digital Elevation Model(DEM) data of Fujian province with a spatial resolution of 90 m is selected as the geographic signal. The two-dimensional empirical mode decomposition(BEMD) is applied for decomposition processing to obtain several two-dimensional intrinsic mode functions(BIMF1~ BIMF3) with different scales and different physical meanings as well as the corresponding residual ORIG. These BIMF components correspond to the microtopography of different scales, and ORIG shows the geomorphic distribution trend of the study area, reflecting the general distribution area of plains, hills and mountains. The optimal calculation unit is determined by the method of variable point analysis, and the first order classification of each signal area is carried out by using the degree of relief, and the second level classification is carried out according to the absolute height. Finally, the first class classification and the second order classification are combined to realize the classification of terrain. This classification process reflects the complex characteristics of geomorphological assemblage in the study area. The results show that:(1) Superimpose BIMF components and extract the components and regions larger than 74 m as high-frequency signal regions. The region is dominated by the low mountains with small relief amplitude, and is accompanied by middle mountain with small relief amplitude and hills.(2) The region with residual height less than or equal to 340 m in ORIG was extracted, and the region containing high frequency signal was removed as the lowfrequency signal region, which was mainly plain and hills.(3) The remaining area is defined as the intermediate frequency signal area, and the geomorphology of the area is dominated by flat hills and small mountains wi

关 键 词：地形分解 数字高程模型(DEM) 二维经验模式分解(BEMD) 本征模函数(BIMF) 余量函数(ORIG) 地形起伏度 高频 低频 

分 类 号：P931[天文地球—自然地理学] P208