下载中心
优秀审稿专家
优秀论文
相关链接
摘要
针对复杂地貌形态的多比例尺表达中的等高线容易相交、地性特征描述困难和表达过程缺乏自适应等难题,提出了基于小波理论的复杂地貌形态的多比例尺表达模型,为上述问题的解决提供了新的思路和有效途径。
关键词:
复杂地貌 多比例尺表达 小波分析 Lipschitz 指数The multi-scale representation model of complex landform based on two-dimensional wavelet transformation is proposed in this paper. The new idea and principle of this model can completely get rid of intersection of different contours which commonly occurred in almost all models used before. Thus,it could be said that by theory and method the model can preserve the veins of landform,maintain the coordinate relations among the contour lines,besides,it has adaptive property. The experiments on that model give the following conclusions: ① The landform characteristics such as the peaks,saddle points,valley lines,intersections of valleys,ridge lines of mountains can be preserved very well,so the structure and roughness of the global landform will be retained. ② The relative positions of the contour lines are maintained precisely,so the shape of the landform such as the outines of mountains,the directions of ridges and valleys are retained quite well. ③ The rates of changes of the amount of information,the simplification of the contour lines,the extent of landform generalization for different levels of decomposition or reconstruction are consistent and stable,besides,they coincide with the visual feeling and standard of the ordinary people. ④ The Lipschitz index,which is related to the roughness of the landform,is used to calculate the threshold value in the model,thus the threshold which control the amount of information being retained is directly linked with the complexity of the landform and could be adjusted adaptively. ⑤ Because of the flexibility of the threshold value and the stability of the method,the multi-scale representation based on that two dimensional wavelet model is suitable for more kinds of landforms.