AVALIAÇÃO DE DIFERENTES MODELOS DIGITAIS DE ELEVAÇÃO NA GERAÇÃO DE MAPAS DE SUSCETIBILIDADE A INUNDAÇÃO A PARTIR DO MODELO HEIGTH ABOVE THE NEAREST DRAINAGE (HAND)

Evaluation of different digital elevation models in the generation of flood susceptibility maps from the Heigth Above the Nearest Drainage (HAND) model

Abstract

The HAND model is a widely used tool to indicate areas susceptible to flooding. However, the choice of the font and resolution of the MDE influence the result. Thus, we sought to evaluate the performance of different DEMs in the generation of flood susceptibility maps using HAND. Using data from SRTM (90 and 30m) and ALOS PALSAR (12.5m). Having as study region the city of São João do Rio do Peixe-PB, which has a long history of flooding. The performance of each map was analyzed based on the accuracy in classifying landmarks with a history of flooding. Thus, a flood map for the entire municipality was obtained from the SRTM at a resolution of 90m, where areas with high susceptibility were identified and thus generated maps for these regions, two of the SRTM and drainage thresholds of 2.500 and 1.000.000 pixels and two of the MDE ALOS PALSAR and threshold of 51.000 and 6.000.000 pixels. The analysis of the performance of the maps identified that the MDE SRTM map with a threshold of 2.500 pixels was the most accurate, while that of the MDE ALOS PALSAR with a threshold of 51.000 pixels was the least representative of the area.