论文部分内容阅读
This paper presents a study on the characteristics of multiple time scales of bankfull discharge and its delayed response to changes of tlow conditions using continuous wavelet analysis for data from selected hydrologieal stations in the Yellow River basin.Results showed that bankfull discharge series had one or two dominant lime scales.For example,the Huayuankou station in the lower reach of the Yellow River had two dominant time scales of 19 20 years and 5 6 years.The dominant time seales of the bankfull discharge series were generally consistent with the dominant time scales of water discharge and sediment concentration series,indicating thai the channel morphology inherits the characteristics of the hydrologieal system in terms of multiple time scales.In addition,the wavelet coefficients of the bankfull discharge series had a phase difference in relation to those of the sediment concentration series,with a delay time that varied from 3 to 16 years at different sites.This delay time or relaxation lime is a result of the delayed response of bankfull discharge to How conditions,which was significant for channel adjustments in response lo changes of tlow eondilions.The findings of the multiple lime scales and the delayed response are of importance for further study of channel morphology of fluvial systems.
This paper presents a study on the characteristics of multiple time scales of bankfull discharge and its delayed response to changes of tlow conditions using continuous wavelet analysis for data from selected hydrologieal stations in the Yellow River basin. Results showed that bankfull discharge series had one or two dominant lime scales. For example, the Huayuankou station in the lower reach of the Yellow River had two dominant time scales of 19 20 years and 5 6 years. The dominant time seales of the bankfull discharge series were generally consistent with the dominant time scales of water discharge and sediment concentration series, indicating thai the channel morphology inherits the characteristics of the hydrological system in terms of multiple time scales. In addition, the wavelet coefficients of the bankfull discharge series had a phase difference in relation to those of the sediment concentration series , with a delay time that varied from 3 to 16 years at different sites.This delay time or relaxation lime is a result of the delayed response of bankfull discharge to How conditions, which was significant for channel adjustments in response lo changes of trough eondilions. The findings of the multiple lime scales and the delayed response are of importance for further study of channel morphology of fluvial systems.