Openness: A visualization parameter for two-dimensional relief

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.