Current Status of Urban Environments in Asia
Figure 1: Methodology Flow Chart
Figure 2: 3D CAD Files
Figure 3: Point Features
Figure 5: Area Features
After extracting points, lines and polygons, the data (Figure 6) are split into two different datasets, one planimetric and the other as DEM or DTM features. The features are converted into either shapefiles or as feature classes for the development of the geodatabase. CAD data are also converted into the geodatabase. Converted CAD files are stored in geodatabase as feature datasets and feature classes. Feature class files are shown in the orthophoto in Figure 7. Using these datasets, DEM/DTM features are extracted, such as roads, mass points, rivers, break lines, manholes and streams, at one-meter contour intervals (Figure 8). After preparing the contour map, the DEM can be generated with the base contour values (Figure 9). ArcScene is used to add heights to each vector (points, lines and polygons) and raster layer (Figure 10).
Figure 6: Overall Input Features
Figure 7: Converting files Cad to GIS
Figure 8: Contour Map
Figure 9: Digital Elevation Model
Figure 10: 3D Viewing in ArcScene
Planimetric data are added to the map (Figure 11). In addition, these DEM data and planimetric data are used to assign the extrusion base heights of DEM values and assigned the planimetric feature heights (Figure 12). Finally, from the output all the planimetric features are clearly visualized in 3D. When all features are assigned with exact heights in the globe we can clearly see the 3D city model (Figure 13).
The results can be used for proper network analysis and city planning. This 3D model can represent the city in virtual reality with exact scale. The results can be used to find a place for pipelines and drainage networking. Based on the analysis, urban authorities can plan to develop the infrastructure and suitable lands for industrialization and urbanization. The current planning and subsequent 3D model can be used for site selection of telecommunication and power lines. Based on this analysis we can plan for new roads and improve existing road infrastructure. The present study is also helpful for utility mapping. Proper planning can be initiated to help to convert fallow land to urban city (Figure 14).
Figure 11: Planimetric Features
Figure 12: 3D View Overlay with DEM
Figure 13: 3D View Overlay with Ortho photos
Figure 14: 3D Urban City Planning
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