出版社：Editora da Universidade Federal de Roraima (EdUFRR)
摘要：In the State of Roraima the territorial occupation occurs inordinately. Gully (cave-in caused by heavy rains) established in the Mountain of Tepequém reflect this reality. The objective of this work was to characterize the erosion susceptibility of the soils of 8 gullies and to quantify the rain erosivity in the Mountain of Tepequém. The erosion susceptibility was esteemed through the proportion among sand, silte and clay in the surface and subsurface layers of the soil. The rain erosivity was calculated through the application of two equations [EI30 = 36.849 (p2/P)1,0852 and EI30 = 68,730 (p2/P)0,841], respectively Morais et al., (1991) and Lombardi Neto; Moldenhauer (1992), over a 11 year-old pluviometric data series. The soils which were reached by linear erosion expressions (gullies) were classified as HIDROMORPHIC QUARTZARENIC NEOSOIL. The results demonstrated that they are sandy and not cohesive. The calculated values of annual rain erosivity were 16.697,9 MJ mm year-1 ha-1 h-1 and 11.438,9 MJ mm year-1 ha-1 h-1, which represent a very strong erosivity. From point of view of the erosive processes, the Mountain of Tepequém represents a fragile environmental system, which reinforce the importance to insure limited human activity.
