Avaliação da estimativa do potencial de erodibilidade de solos nas margens de cursos de água: estudo de caso trecho de vazão reduzida Capim Branco I Araguari Minas Gerais

Abstract

The present work is a proposal of evaluation of the estimate of the erodibilidade potential through different methods inside of which we have rehearsals of evaluation of the erodibilidade of indirect form and rehearsals of evaluation of the erodibilidade in direct form. Haul of the estimate of the soil loss through the Universal Equation of Loss of the soil (EUPS) and the Universal Equation of Loss of the Modified soil (MUSLE). The experimental work was developed in the right margin of the passage of flow reduced of the hydroletric power plont Capim Branco I (TVR-CBI); Araguari in the State of Minas Gerais; Brazil. In the comparison of the estimate of soil loss made calculations in base in the concentration measured daily rate of the sub-basin incremental with the results obtained through the mathematical models EUPS, MUSLE, it was verified that one exists differentiates very considerable since the soil loss esteemed through EUPS was 13 times larger and the result of MUSLE was of 6 times. It is believed that is due for the fact that in the estimate of the soil loss through the mathematical models in the face of the difficulty to obtain data of intensity pluviométrica of the area in study used in the estimate of the parameters R and Rw values proposed in the literature.Inside of the physical and mechanical characterization of the soil, the granulometria study showed that the soil is a fine sand (P2) and sand average the fine (P3), both with fine (33% and 20%). On one side, the sand is not uniform, what reduces its erodibilidade, for other thefine ones are little plastic and it is not structured, what increases the susceptibilidade to erosion processes. Now the other rehearsals confirmed the sandy characteristic and no structured of the soil. Several rehearsals and MCT showed that the erodibilidade of this soil this directly related to his/her degree of initial saturation. All that, larger saturation initial, larger the susceptibilidade. It seems that always permanence grand quantity of air stays, even after the entrance of water. The rehearsals of evaluation of the erodibilidade in direct form showed a low erodibilidade. This fact should be associated witnesses of organic matter in the sample and to the form of execution of the rehearsal Inderbitzen, since in this work the rehearsal Inderbitzen was used to simulate the effect of the drainage to laminate if it didn't endorse the impact of the rain drops that has an effect according to the literature still larger in unprotected soils. Finally, the assoreamento in the bottom of the gutter of the river Araguari, produced by the erodibilidade of the area of the study, was considered