Time and Flow Characteristics of Component Hydrographs Related to Rainfall–Streamflow Observations

This study investigates the shape characteristics of hydrograph components of the Wu-Tu watershed in Taiwan based on ob- servations of rainfall and streamflow. Component hydrographs were modeled using a model of three serial tanks with one parallel tank. The block kriging method was used to calculate the hourly mean rainfall of events, and eight model parameters of 34 cases were derived from the shuffled complex evolution optimal algorithm. The remaining 18 events were used to verify the applicability of the calibrated parameters. Results show that (1) times to peak of hydrograph components are positively nonlinearly correlated to peak time of rainfall; (2) peak dis- charges of hydrograph components are linearly proportional to those of streamflow hydrograph; and (3) relationships of total discharges also have direct ratios between hydrograph components and observed streamflow. Using the procedures proposed in this study, three evaluated shape characteristics of component hydrographs can be easily used to rapidly determine shapes of simple hydrographs. DOI: 10.1061/ (ASCE)HE.1943-5584.0000675. © 2013 American Society of Civil Engineers. CE Database subject headings: Reservoirs; Hydrographs; Streamflow; Rainfall. Author keywords: Block kriging; Linear cascade reservoirs; Hydrograph components; Streamflow; Shape characteristics.