Control of erosion processes resulting from disruption of adductor in the Serra da Mantiqueira, SP, Brazil

Abstract

In the southern escarpment of the Serra da Mantiqueira, northeast geographic divider between the State of Sao Paulo and Minas Gerais, there was an environmental accident caused by the disruption of an adductor whose purpose is to lead the water from a reservoir located at an altitude of 1820 m to the machine house where there is an electric generator located at 750 m. This accident resulted in the formation of a scar on the hillside forest, with removal of soil and vegetation. To reverse the erosion processes, a methodology was developed consisting of the use of four barriers (numbered I to IV) formed by seedlings of Bambusa mutiplex (Lour.), whose purpose was to divert the water runoff in order to provide the regeneration of native vegetation. Stalks of bamboo intercropped with Bambusa multiplex were used to contain debris in two gullies formed by erosion. The development of vegetation was monitored for 18 months and evaluated by the application of a Leopold Matrix composed of 5 points, which are: erosion, regeneration of vegetation, success of bamboo planting, installed conservation structures and functionality. The purpose of the matrix was to demonstrate the effectiveness of interventions using bamboo. The result of the classification matrix enabled the quantitative and qualitative classification of the interventions, resulting in five levels, where the barriers I, II and IV were considered to be of very high efficiency, and barrier III was considered to be of high efficiency. The contention of the gully was considered to be of medium to very high efficiency.