Free and open-source software for Geographic Information System on coastal management: A study case of sea-level rise in southern Brazil

Abstract

This work assesses sea-level rise impact using three different models created on Free and Open-Source Software for Geographic Information System to help coastal managers in the initial stages. The End Point Rate for QGIS (EPR4Q) computes a coastline projection using the End Point Rate method. The Uncertainty Bathtub Model (uBTM) analyses the effects of sea-level rise through the uncertainty of sea-level projections and the vertical error of the Digital Elevation/Terrain Model. The Bruun Rule for Google Earth Engine Model (BRGM) predicts the position of the shoreline with sea-level rise, using topographic and bathymetric data from Unmanned Aerial Vehicles and Coastal Modeling System, respectively. Based on the regional projections of the Special Report on Climate Change and Oceans and Cryosphere of the Intergovernmental Panel on Climate Change, the models were applied to a study case on the coast of Rio Grande do Sul—Brazilunder different scenarios of sea-level rise expected by the end of this century. The results showed a maximum coastal retreat for the year 2100 of -502 m and -1727 m using EPR4Q and BRGM, respectively. The uBTM with Mapbiomas land use showed a maximum of 44.57 km 2 of urban area affected by sea-level flooding. This study highlights the feasibility of conducting coastal management analysis in GIS environment using non-commercial software.