Openness: A visualization parameter for two-dimensional relief
ZHANG Jie1,2, LIANG Mingjian3, SHAO Yanxiu4
1. Faculty of Earth Science, China University of Geosciences(Wuhan), Wuhan 430074, China; 2. Nanjing Center, China Geological Survey, Nanjing 210016, China; 3. Seismological Bureau of Sichuan Province, Chengdu 610041, China; 4. Lanzhou Institute of Seismology, China Earthquake Administration, Lanzhou 730000, China
Abstract：As one of visualization parameters for two-dimensional relief, Openness does not require light source and is not affected by the shadow of adjacent terrain. The parameter places more emphasis on the concave and convex of the terrain, which improves the intuitive stereoscopic impression of images. Openness can be calculated from multiple DEM sources, and can analyze the landform characteristics at different scales as well. The estuary of the Minjiang Estuary has various types of landform structure; therefore, the authors chose the area as a study area and calculated its Openness parameter on the basis of SRTM (90 m) elevation data so as to study the initial application of the parameter in terms of topography. The results show that, in comparison with traditional two-dimensional visualization methods such as shaded relief, Openness could display a better image which highlights the concave and convex of the terrain and reflects more details of the topography.
[1] 汤国安,刘学军,闾国年.数字高程模型及地学分析的原理与方法[M].北京:科学出版社,2005. Tang G A,Liu X J,Lv G N.Principles and Methods of Digital Elevation Model and Analysis[M].Beijing:Science Press,2005. [2] Chiba T,Kaneta S,Suzuki Y.Red relief image map:New visualization method for three dimensional data[C]//The International Archives of the Photogrammetry,Remote Sensing and Spatial Information Sciences,Part B2.Beijing,2008(37):1071-1076. [3] 施祖辉.地貌晕渲法[M].北京:测绘出版社,1985. Shi Z H.Relief Shading Technique[M].Beijing:Surveying and Mapping Press,1985. [4] 杨海林,王家廞.数字地球中实时地形晕渲的实现方法[J].北京航空航天大学学报,2011,37(12):1585-1588. Yang H L,Wang J X.Method of realtime hill-shading in digital earth system[J].Journal of Beijing University of Aeronautics and Astronautics,2011,37(12):1585-1588. [5] Yokoyama R,Shirasawa M,Kikuchi Y.Representation of topographical features by openness[J].Journal of the Japan Society of Photogrammetry and Remote Sensing,1999,38(4):26-34. [6] Yokoyama R,Shirasawa M,Pike R J.Visualizing topography by openness: A new application of image processing to digital elevation models[J].Photogrammetric Engineering and Remote Sensing,2002,68(3):257-265. [7] Pike R J,Acevedo W,Thelin G P.Some topographic ingredients of a geographic information system[C]//Proceedings,International Geographic Information Systems Symposium.Arlington,Virginia(NASA,Washington,D.C.),1988:151-164. [8] 曾燕,邱新法,何永健,等.起伏地形下黄河流域太阳散射辐射分布式模拟研究[J].地球物理学报,2008,51(4):991-998. Zeng Y,Qiu X F,He Y J,et al.Distributed modeling of diffuse solar radiation over rugged terrain of the Yellow River Basin[J].Chinese Journal of Geophysics,2008,51(4):991-998. [9] 孙娴,林振山,王式功.山区地形开阔度的分布式模型[J].中国沙漠,2008,28(2):344-348. Sun X,Lin Z S,Wang S G.Distributed modeling of terrain opening extent over mountainous terrains[J].Journal of Desert Research,2008,28(2):344-348. [10] 罗庆洲,刘顺喜,曾齐红,等.基于DEM的本影与落影判断研究[J].国土资源遥感,2009,21(2):29-31.doi:10.6046/gtzyyg.2009.02.06. Luo Q Z,Liu S X,Zeng Q H,et al.Research on identifying umbra and drop shadow based on DEM[J].Remote Sensing for Land and Resources,2009,21(2):29-31.doi:10.6046/gtzyyg.2009.02.06. [11] 罗庆洲,黄微,闫业超,等.天空开阔度的精确计算研究[J].遥感技术与应用,2009,24(4):533-536. Luo Q Z,Huang W,Yan Y C,et al.Research on calculating sky-view factor with high precision[J].Remote Sensing Technology and Application,2009,24(4):533-536. [12] 罗庆洲,李先华,梅安新.邻坡反射辐射对地物反射率计算的影响评估[J].武汉大学学报:信息科学版,2012,37(8):932-935. Luo Q Z,Li X H,Mei A X.Impact evaluation of neglecting radiance reflected from neighboring slopes on calculating target reflectance[J].Geomatics and Information Science of Wuhan University,2012,37(8):932-935. [13] Prima O D A,Yoshida T.Characterization of volcanic geomorphology and geology by slope and topographic openness[J].Geomorpholoby,2010,118(1/2):22-32.
2015, Vol. 27 
