Generación de un DEM usando PDI para la extracción de líneas de agua en imágenes satelitales

BLANCO MONROY, K.L.; REVOLLO SARMIENTO, G.N.; REVOLLO SARMIENTO, N.V.; DELRIEUX, C.A.; PERILLO, G.M.E.

Anuario de Instituto de Geociencias

nstituto de Geociencias - UFRJ

Lugar: Rio de Janeiro; Año: 2017 vol. 40 p. 211 - 220

The waterline extraction method is an effective tool to study changes in tidal flats or shorelines. Among other applications,when adequate information is available, it can be taken advantage in the construction of Digital Elevation Models (DEMs) of theintertidal area. In this paper we present new waterline extraction algorithms, which are applied to generate a DEM of the internalintertidal zone in the Bahía Blanca Estuary. For this, waterlines from satellite images were extracted. We selected a set of Landsat-8images generated in 2014 with representative tidal conditions. Initially, to identify the waterline, we developed and applied to eachimage a novel segmentation algorithm based on minimum distance to multiple prototypes, each pixel selected is representative eitherof water or land. With the segmented image, the contour of the waterline was extracted using a specific marching algorithm. Then, thetide height was associated to each waterline. The resulting geographic information, included in a GIS, was employed to generate theDEM using an interpolation method. To validate the accuracy of the model, we compared the height of the DEM at several point siteswith bathymetric information gathered in an oceanographic cruise carried out in the same year. The results show a good correlationbetween the computed DEM and this in situ bathymetric information.