Geo-hidroecological domains in the Tijuca massif, RJ: support to the hydrologic and erosive process knowledge

Abstract

Tijuca massif constitute a geomorphologic system, where the replacement of vegetation cover by urban features and grass areas, contribute to change in the hydrological behavior.As a consequence of this change there is an increase of erosion processes by different mechanisms, and in the solid and liquid discharge that can affect lowlands. The understanding of these processes, in a geoecological research above center of interest geomorphologic view requires the interpretation of the elements control them, in structural, functional and dynamic way. This way, the aim at interpreting the transformation processes that occur in this massif, and delimitate the use and covering of the soil that with others structural and functional elements define areas with differents hydrological and erosive results (geo-hydroecological dominions). To define this dominions, it was taken into consideration systematically, the soil use, type and characteristic of the soil, geology and drenage efficiency, using geoprocessing technic and analytic-integrative method. The results show that in the sectors 1, 2 and 5 have dominions that make is inundation in them lowlands. The areas of urbarn ocupation in the sectors 2, 3 e 4 concentrate the landslides, because in this areas occur the bigger drenage efficiency, reflex of higher gradients and density of concave axis. In this way the continuatily will promote a drastic growth of Tijuca massif's erosive processes.