Processos erosivos e modelagem hidrológica: o estado da arte.

Abstract

Although soil erosion is a natural process, a series of factors can cause its acceleration, resulting in significant environmental damage, such as the siltation of drainage channels and the loss of soil fertility. Hydrological models are important tools that make possible measuring the average soil loss and identifying most susceptible areas to these processes. This study aims to analyze and theoretically discuss the issue of soil erosion through hydrological models. To achieve this, the study is organized into three modules: the analysis and description of erosion processes (conditioning factors, typologies, and mechanisms), the use of hydrological models (history and classification), and the application of hydrological models in Brazil (types of applications and results reported by the referenced authors, and the application of hydrological models in geography). For the development of the theoretical framework that supported subsequent discussions, both physical and digital resources were consulted. Digital works were found through search systems such as Clarivate (Web of Science), Scopus, Scielo, and Google Scholar, using terms related to erosion, soil loss, and hydrological modeling in Portuguese and English. The works in physical format were searched for in the libraries of the Federal University of Santa Maria. Regarding the discussions and results obtained, it is emphasized that the main factors controlling erosion processes are related to rainfall erosivity and soil erodibility. Thus, the occurrence of erosion processes depends on factors such as climate, soil, rock, topography, vegetation cover, and anthropogenic activities. And about the typology and mechanisms of erosion processes, a sequence of processes was highlighted, ranging from raindrop impact erosion, sheet and linear erosion, to more complex processes such as internal erosion and gully erosion. Subsequently, regarding the application of models to the study of water erosion, deterministic models, particularly empirical and physically-based ones, are highlighted due to their broader use. Deterministic models, especially through the USLE, are the most widely applied, including in Brazil, where the use of hydrological models is still limited to a relatively small number of studies compared to countries with similar territorial dimensions. In geography, however, the application of models is restricted to a few authors, which doesn’t reflect the interdisciplinary potential of this science or its ability to integrate analyses with approaches beyond the physical environment. Hydrological models are powerful tools for making targeted decisions in the control of accelerated erosion.