DEM构建及地形特征线提取研究

A study on DEM construction and topographic feature line extraction

格网DEM是数字地面模型的重要数据表现形式,基于格网DEM提取的山脊线、山谷线是地形骨架结构的表达与数字地形分析的重要方面。通过比较距离倒数乘方法、自然邻域法、克里金法、薄板样条函数法、趋势面分析法5种空间内插方法在本溪关门山地区的适用性,选出最优法用于格网DEM的构建。基于格网DEM,对比运用水文分析法和曲率判别法两种方法提取山脊线、山谷线的结果,并研究两种提取算法的融合效果。以GeoScene Pro建模和脚本的形式分别实现了DEM构建、等高线曲率计算、山脊线与山谷线提取;制作了本溪关门山地区数字高程模型图、等值线专题图、山脊线与山谷线专题图等。提出了坡度、平面曲率与等高线曲率的转换方法;对水文分析法和曲率判别法做出了改进,并提出了基于水文分析法和曲率判别法的融合算法,进一步提高了山脊线、山谷线提取的准确率。融合算法兼具二者之长,提取结果较为全面,整体性较好。

Grid DEM is an important data representation of digital ground model.Ridgeline and valley line extracted based on grid DEM is an important aspect of the expression of terrain skeleton and digital terrain analysis.By comparing the applicability of five spatial interpolation methods such as distance reciprocal power,natural neighbor,Kriging method,thin-plate spline method and trend surface analysis,in the Guanmenshan area,Benxi,the optimal method is selected for the construction of grid DEM.Based on grid DEM,the results of ridgeline and valley line extraction by hydrologic analysis method and curvature discrimination method were compared,and the fusion effect of the two extraction algorithms was studied.In the form of GeoScene Pro modeling and script,DEM construction,contour curvature calculation,ridgeline and valley line extraction are realized respectively.Digital elevation model map,contour line thematic map,ridge line and valley line thematic map were made for the Guanmenshan area of Benxi.The conversion method of slope,plane curvature and contour curvature is proposed.The hydrologic analysis method and curvature discrimination method are improved,and a fusion algorithm based on the hydrologic analysis method and curvature discrimination method is proposed,which further improves the accuracy of ridgeline and valley line extraction.The fusion algorithm has the advantages of both,and the extraction results are more comprehensive and holistic.