A importância da geomorfologia nos estudos ripários: estudo de caso da bacia do rio Apuaê-mirim, norte do Estado do Rio Grande do Sul

Abstract

The present paper traces a discussion about the importance of geomorphology in determining riparian environments taking as a reference the case study of the hydrographic basin of the Apuaê-Mirim river, located in the northern region of the State of Rio Grande do Sul. The main question addressed in the research was based on the indication of how geomorphology acts like a controlling factor, either as a conditioner or as a limiter, in the spatial consolidation of riparian environments. For this purpose, a multiscale approach referenced systematically to water courses was used, alluding to three levels of spatial analysis, these being the drainage network (or the hydrographic basin), the river's segments, and the river's reach. For the first instance, the lithostructural and climatic influences (past and present) inherent to the regional geomorphological evolution and the constitution of the valleys were evaluated, in the second, the morphometric aspects of the valleys associated with the types of reliefs were considered, and in the last, the relationships the forms of relief at the bottom of valleys (plains, the slopes' shapes, cross-sectional profiles of valleys, etc) with hydrogeomorphological and pedological aspects to identify and characterize the riparian environments that occur. The realization of these studies was based on the execution of field work in association with geoprocessing activities, for the analysis of geomorphological facts and for obtaining the results. In general, it was found that geomorphology (in the hierarchical succession of forms in multiple spatial scales) has a great influence on the conditions of existences and on the way in which riparian environments are constituted within the study area.