Digital Elevation Model of coastal and flood plains obtained from vector data: an alternative method applied to the Coatzacoalcos fluvial plain (Mexico)

Abstract

Vector data can be used to generate Digital Elevation Models (DEMs), but in the case of fluvial and coastal plains, according to topographical constrains, the interpolation requires other types of intervention to achieve a result of quality. For Mexico, neither data base check points nor LiDAR Digital Terrain Models (DTMs) are available for such areas, so that vector data are frequently used to generate DEMs. This lack of information led us to propose a method to obtain an alternative DEM by using the available vector data, especially because these fluvial and coastal plains are frequently affected by floods. The RMSE (root mean square error) as well as the standard deviation of the generated DEM are lower (0.0074 and 0.0059) than for the LiDAR DTM (0.0945 and 0.0793). On the other hand, the validation is also based on the comparison of flood simulation applied to the resulting DEM and the corresponding LiDAR DTM. The area covered by the simulated flood is 716.63 km2 for the resulting DEM; meanwhile, an area of 787.82 km2 is obtained using LiDAR DTM. Concerning the volume, this is 1.02 km3 for the DEM and 0.86 km3 for the LiDAR DTM.