MONITORAMENTO AUTOMATIZADO DO ESCOAMENTO SUPERFICIAL EM PARCELA EXPERIMENTAL INSTALADA EM TALUDE DE CORTE / AUTOMATIC RUNOFF MONITORING ON EXPERIMENTAL PLOT INSTALLED IN CUT-SLOPE

doi: 10.12957/geouerj.2017.18523 Surface runoff monitoring on cut-slopes has been an issue addressed in several recent studies, but in experimental plots assessments have been limited to the storage of runoff in tanks and measurement of daily volumes in a laborious and time consuming process. In this study an automatic system for monitoring runoff on an experimental plot was developed using a Parshall type weir instrumented with an ultrasonic level transmitter. The runoff volume passes through the weir and then is stored on tanks where measurements by the conventional method were conducted. A plot of 11 m by 4 m was installed in a cut slope (60 m x 15 m and slope 66%). The maximum instantaneous flow rate during the study period was 8.35m³/h, in response to a 30.98mm/15min intensity rainfall. The results proved the efficiency of the system, and showed that runoff volume will change in a few minutes responding to changes in rainfall intensities. Deposition of sediments occurred in the system, indicating the need for periodic maintenance of the weir after a prolonged period of heavy rainfall, but there were no problems in measuring the levels during the monitored period.