Assessing Accuracy and Calibration Importance of Tipping Bucket Measurement Boxes for Monitoring Soil Erosion

Abstract

In situ soil erosion monitoring is essential to investigate the effects of soil erosion control measures and to provide effective management strategies to maintain soil health and for future climate change adaptation. However, reliable soil erosion monitoring in the field depends on the accuracy of the installed measurement equipment under a range of environmental conditions. This study evaluated how slot position in a multislot divisor, runoff intensity and soil type affect runoff and sediment measurements of tipping bucket measurement boxes for soil erosion monitoring. A controlled experimental setup simulated runoff events using two different soil types to analyse potential differences in collected runoff, sediment and its textural composition among slot positions. Based on the results, we present a calibration strategy for tipping bucket measurement boxes to adjust for deviations in collected runoff and sediment. The results reveal that tipping stability declines at frequencies over 40 tips per minute, with the central slot collecting up to 4% of water volume, exceeding other slots. Water and sediment collection at the central slot maintained a consistent pattern under 40 tips per minute, while deviations in sand content between collected and parent soils were observed but did not impact overall sediment mass significantly. Calibration functions applied to a measurement plot during a period of natural runoff events under field conditions exhibited underrepresentation of runoff and sediment levels in uncalibrated records. Runoff calibration results in more accurate total erosion estimates, especially crucial for high-frequency runoff events where uncalibrated results overestimated soil loss by up to 13%.