Avaliação da remoção de sedimentos pela operação de nivelamento de estradas florestais

The forest roads construction inevitably causes environmental impacts to adjacent ecosystems and streams. Also the routine activities of roads maintenance may similarly cause environmental impacts of about the same magnitude. The material scraped from the roadway by the motor grader is usually distributed along the roadsides, from where it may easily be washed out toward the streams. Therefore, quantifying the amount of sediments removed during road maintenance activities may provide important information of this stream sedimentation potential. For this purpose, three forest roads were divided in 30 m long segments, marked with leveled stakes. A nylon thread was then stretched across the leveled stakes and the distance from the nylon thread to the road surface was measured before and after the mechanical scraping of the road. The average removal of sediments was of 2,13 cm. Considering the mean density of soil 1,6 g cm -3, the average removal of sediments was of 341 t ha -1 of road. Considering still a 3,9 m wide and 150 m long road as an example, the total amount of removed sediments would be around 19,9 t. Road maintenance, therefore, must be well planned in order to avoid or minimize stream sedimentation.

Proposta de recuperação e manejo de nascente em área rural do município de Álvares Machado – SP

The lack of proper planning in intervention works of runoff water on rural properties and rural public roads leads to economic damage and loss of environmental quality. The impact of the action without technical base is soil erosion, siltation of water sources, loss of the quality and availability of water, invalidating areas for cultivation and livestock. The conservation of headwaters requires beyond regeneration of the environmental characteristics the repair and management of the degraded watercourse in order to control erosion. This graduate work in Environmental Engineering from Universidade Estadual Paulista Julio de Mesquita Filho - UNESP Presidente Prudente proposes a headwater recuperation and management in rural area of Álvares Machado municipality, São Paulo State, through the method of deep drainage applied to the case of a rural road near the outcrop of water. This technique consists in the installation of draining structures in sub-areas of the road surface, or sub-gutter and/or in the platform border in order to conduct the underground flow of water and reduce the loss of sediment in water flow. Therefore, was performed a historic study of use and occupation of land in the municipality of Álvares Machado, portraying transformations of the landscape caused by human action. Geology, geomorphology, pedology and hydrogeology data were collected from the study area in order to establish the conditions that led into the current situation of degradation and formulate an effective intervention strategy for civil works

Influence of Sources and Meteorology on Surface Concentrations of Gases and Aerosols in a Coastal Industrial Complex

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Atmospheric particulate polycyclic aromatic hydrocarbons from road transport in southeast Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)