Processing SRTM DEM data for national landslide hazard assessment

This paper describes the processes carried out during the editing of SRTM data for the Cuban Archipelago: the analysis for producing Digital Elevation Model (DEM) derivative maps; and a geomorphometric landslide hazard assessment at national level. As the base data is unedited, intensive work was done to remove/diminish the numerous voids and other spurious points such as anomalously high (spike) or low (well) values. Calibration was especially necessary in the water bodies, shaded mountains areas and in coastal zones where radar backscatter signal produce values considered erroneous. The processing and analysis was achieved through the utilization of GIS spatial techniques and remote sensing processing software.

Geomorphometric conditions are one of the most important aspects in producing landslides. In order to make a national landslide hazard assessment the geomorphometric susceptibility of the Cuban Archipelago was produced. Slope angle and internal relief (vertical dissection) DEM derivative maps were used for producing the landslide geomorphometric susceptibility. The combination of these maps shows areas where landslides are most likely to occur; proportional to the level of the value assigned to the geomorphometric factors. As expected, areas prone to landslide coincide with the main mountain systems in Cuba. Using this analysis, these areas could be compared at the national level and details of more susceptible zones were found in each mountain system.