Auto Hydro Break Line
|Authors: George J. Toscano, Uday Kiran Gopalam, and Venkat Devarajan
In rural areas, hydro break lines are necessary to create LiDAR derivative products such as TINs, contours, DEMs etc. Water body detection and delineation are necessary to generate hydro break lines. Hydro flattening follows the detection and delineation of water bodies (lakes, rivers, ponds, reservoirs, streams etc.). Manual hydro break line generation is time consuming and expensive, especially when there are large number of lakes, rivers and their tributaries. Accuracy and processing time depend on the number of vertices marked for delineation of break lines. Automation with minimal human intervention is desired for this operation. In this paper, we proposed an advanced algorithm to detect water bodies automatically using both LiDAR elevation and intensity data. We used two distinguishing characteristics to detect water bodies. The first one is that the surface of water body is a flat area and the elevation of it is lower than that of the surrounding area. The second one is that spectral reflectance of water is very small in the near infra-red range compared with vegetation and other topographic features. Beyond these two broad strategies, we used additional techniques to fine tune the algorithm. After detecting water bodies, we generated 3D break lines. Finally, we performed a comparison of automatically generated break lines with their semi-automated/manual counterparts and we discussed the results.
|University of Texas at Arlington |