Calibration and influencing factors analysis of stage-discharge relation of non-standard section method in open channels
In order to explore the calibration problem of the stage-discharge relation curve for open channel non-standard section flow measurement,25 channel water measurement sections in a regiment field of the Third Division of Xinjiang were taken as the research object,and the stage-discharge rela-tion was calibrated using a FlowTracker 2 handheld acoustic Doppler current meter.Based on the actual measurement results,the stage-discharge relation curves of each channel water-measuring section were calibrated,and the calculated curves were subjected to sign inspection,line fitting testing,deviation numerical testing,and error analysis.On this basis,the flow rate was simulated,and the influencing factors of the combined flow fitting parameters were analyzed.The results show that among the 25 cali-brated channel water measurement sections,14 sections have stable stage-discharge relations,5 sec-tions are affected by backwater,and 6 sections are affected by channel siltation and have unstable stage-discharge relations.Under the same conditions of channel roughness coefficient n,slope coeffi-cient m and slope i,the flow fitting parameters generally correlates positively with the channel bottom width b.Under the same conditions of channel roughness coefficient n,slope coefficient m,and bottom width b,the flow fitting parameters generally correlates negatively with the channel slope i.The re-search results can provide a reference basis for checking the flow measurement accuracy of automatic water-measuring equipment in irrigation areas.