Investigation on error and calibration of tipping bucket runoff and sediment semi-automatic monitoring equipment
[Objective]The aims of this study are to analyze the error law of tipping bucket type semi-automatic monitoring equipment for runoff and sediment in field application,to construct calibration models for runoff and sediment measured by semi-automatic monitoring equipment,and to provide a basis for the application of runoff and sediment semi-automatic monitoring equipment.[Methods]Natural rainfall runoff and sediment monitoring data were utilized to analyze the error of the measured values of runoff and sediment of the tipping bucket runoff and sediment semi-automatic monitoring equipment.Based on the artificial simulated runoff scouring experiment,the runoff and sediment calibration function of runoff and sediment was preliminarily constructed.Combined with the natural rainfall test data,the runoff and sediment calibration models for 7 runoff plots were constructed,and the feasibility of the calibration models was verified.[Results](1)There were some errors between the runoff and sediment monitored by the semi-automatic monitoring equipment and the measured values.At rainfall event scale,the relative errors of runoff and sediment in each runoff plot were between 0.03％～139.52％and 0.32％～346.19％,respectively,and the errors decreased with the increase of runoff volume and sediment amount.At annual scale,the errors of runoff and sediment were between 2.23％～45.03％and-10.38％～103.26％,respectively.The automatic measurement data of runoff was generally greater,whereas there was no obvious regularity in sediment amount.Nevertheless,the error of the monitoring results of the semi-automatic monitoring equipment at rainfall event scale was greater than that at annual scale.(2)The monitoring data of the tipping bucket runoff and sediment semi-automatic monitoring equipment could be calibrated by the linear functions.After the calibration of the runoff model and the sediment model,the root mean square error of runoff volume and sediment mount were greatly reduced.The relative errors were between-0.01％～0.68％and 0.00％～3.52％,which could meet the relevant requirements of runoff and sediment monitoring data error less than 5％.[Conclusions]Although the use of semi-automatic monitoring equipment for runoff and sediment is of great significance for promoting the automation process of soil erosion monitoring and improving the efficiency of data acquisition,further calibration is needed after the equipment is installed.The calibration model established by real runoff data of natural rainfall is better.
runoff and sediment semi-automatic monitoring equipmenttipping bucketerror analysiscalibration model
万方数据
维普
