The record and trends of natural disasters caused by gullies in Brazil

Abstract

AbstractRavines and gullies are advanced stages of linear erosion that occur in many countries, causing economic, social, and environmental impacts. This research aims at analyzing the official record of disasters caused by ravines and gullies in Brazil, with a focus on analyzing the economic impacts. The Brazilian Civil Defense Integrated Information System (S2ID) database was applied in the analysis, combined with a bibliographic review made in the Scopus database. The results obtained from the civil defense database show a growing trend in the number of disasters related to ravines and gullies in the last decade (2011–2020), with 76 cases recorded between January 2013 and May 2019. From these 76 cases, 24 of them were further analyzed to provide information about the socioeconomic impacts. In total, an estimated loss of US$ 54 million was recorded in the considered period. The greatest economic impacts were related to damage to public infrastructure, such as sanitary and sewage water system, buildings and, especially, residential areas in urban perimeters. The spatial distribution of disasters related to linear erosion in Brazil suggests a connection between the development of ravines and gullies and the agricultural frontier of the country, especially in the North and Midwest regions, including the biomes of Cerrado (Brazilian Savanna) and Amazon Rainforest, where the greatest changes in land use occurred between the end of the twentieth and the beginning of the twenty-first century. Although the S2ID is an important data base for analyzing the impacts caused by ravines and gullies, the results suggest that the system's records do not account for medium- and long-term impacts.