Eros?o h?drica sob chuva simulada com varia??o instant?nea de intensidade de precipita??o e avalia??o autom?tica da enxurrada

• Autor(a) principal: Macedo, Pietro Menezes Sanchez
• Data de Publicação: 2022
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/6048
• topic: Simulador de chuva.; Arduino; Padr?es de precipita??o.; Coletor de enxurrada; Rainfall simulator; Precipitation patterns; Flood collector; Agronomia

Water erosion is a natural phenomenon of great importance in the global scenario with regard to the conservation and sustainable exploration of soil and water, and the use of rainfall simulators has generated a lot of relevant information for the understanding of this topic. The improvement of these equipments aiming at the application of rains with variation of precipitation intensity and the development of an electronic runoff collector are crucial steps in the study of erosive processes. Assuming that changing the rotation of the rainfall simulator would make it possible to control the precipitation intensities applied during the simulations and that an automatic runoff collector would facilitate the collection of data in the field, we developed the thesis in three chapters in order to approach the entire procedure adopted in the development and evaluation of devices associated with the InfiAsper rainfall simulator. The aim of the first chapter was to evaluate whether the variation in the shutter disc rotation, associated with its aperture, makes it possible to obtain different rainfall patterns in the InfiAsper rainfall simulator. The installation of electronic components in the simulator's control panel allowed the variation of the shutter rotation during its operation according to previous programming, allowing the simulation of rains with different precipitation patterns. Events with peak precipitation intensity (PI) of 110 mm h-1 and duration of 40 min were adequately simulated by the equipment, with application uniformity above 75%. With this device it became possible to simulate other rain patterns, with different PI and duration, changing the settings for the desired test. The second chapter aimed to evaluate the operability of the InfiAsper rainfall simulator with the new control panel that varies the intensity of precipitation during the application of rain and the soil and water losses associated with different rainfall patterns in a Dystrophic Acrisol with texture clay loam. The panel was programmed to simulate rainfall of 40 min duration and a total depth of 30 mm in a terrain with a slope of 0,09 m m-1, graded in the direction of the contour and in an exposed soil condition. Operating with the new control panel, InfiAsper worked satisfactorily, allowing to vary the intensity of the rains, according to the characteristics of the rains expected in natural events. Intermediate and late rainfall patterns produced greater soil and water losses than the advanced pattern. The intermediate inverted and constant rainfall patterns did?t produce significant losses for the application of an average water depth of 30 mm. The third chapter presents the development and field evaluation of a data collector for rainfall simulators, capable of quantifying runoff volume and automatically estimating the rate of soil loss. Using a microcontroller (Arduino Mega? 2560), sensors with capacitive, ultrasonic and pressure principles were tested to compute runoff volume, and a turbidimeter to compute soil loss rates. Sensors were selected for calibration and data uncertainty. The automatic runoff collector equipped with the PSI.420 pressure transducer and the ST100 turbidity sensor proved to be effective in obtaining and storing data on runoff volume and soil loss obtained during a simulated rain test in the field.