Gullies in Brazil: a spatiotemporal approach between 2000 and 2020

Abstract

This paper proposes to carry out a bibliometric review of the scientific production on gullies, approaching conceptual, methodological, and dimensional aspects and its spatial distribution in Brazil. Therefore, the database available on the Brazilian Journal of Geomorphology (RBG, https://rbgeomorfologia.org.br/rbg/index) was used, along with the papers, expanded and simple abstracts from the National Geomorphology Symposium (SINAGEO, http://lsie.unb.br/ugb/sinageos). The analysis period for the RBG is from 2003 until 2020 and for the SINAGEO is from 2000 until 2018. Overall, the Southeastern region has the greater concentration of works, approaching the hydrological processes that contribute to gullying. As for the definitions, there is a considerable diversity, ranging from those that value only the dimensional criteria, the combination of shape and dimensions or the connectivity with the drainage network. A change in the monitoring techniques is evident nowadays with the use, often combined, of unmanned aerial vehicle (UAV), terrestrial laser scanning (TLS) and satellite/aerial photography, making possible to know the spatiotemporal evolution and the current evolutionary stage of the gullies. Lastly, the works point that the occurrence of gullies in rural and urban areas arise from the unbalance between the energy and matter available in the system.