Abstract:

The Digital Elevation Model (DEM) is one of the most important basic geographic information data of a city. Urban road DEM modeling is an important part of urban DEM construction, while road classification is an important foundation and prerequisite of urban road DEM modeling. However, the existing urban road classification methods have a certain degree of distortion in expression of urban road surface. They cannot accurately reflect the planar morphological characteristics of the road, making it difficult to meet the needs of future surface processes simulation. In view of this problem, based on the composition of urban roads, this paper analyzed the characteristics of urban road morphology from the perspective of DEM modeling. An urban road classification method that takes into account the road morphology was proposed to address the shortcomings of existing road classification methods. Based on this, the DEM of urban roads was further explored. In our paper, we selected a subset of Nanjing as the experimental area and used DLG data was as the data source, to further verify the strengths of our urban road classification method. Our results show that the road morphology derived from the road DEM that was constructed based on our urban road classification method was more consistent with the actual road morphology than the existing methods. The framework structure of urban roads was obvious without abnormal changes on the local road surface. The urban road topography was expressed with finer details, which could be used as an important foundation for rain and flood simulation and hydrological analysis, etc. Thus, the road classification method proposed in this paper can assist the modeling of urban road DEM effectively and provide a reference for the construction of high-precision urban road DEM.

Key words: DEM, city, road, classification, DLG, terrain expression, terrain modeling, DTA