Disaggregation of Annual to daily Streamflows: A linear deterministic method

Abstract

In this study, a linear deterministic methodis applied to disaggregate streamflow from annual to daily data inunregulated stations located on the Kızılırmak river in Turkey. To disaggregate annual streamflows to the daily flow at the target station (TS), annual counterparts at the source station (SS) were identified depending on the minimum error criteria that is estimated based on the volume of three-year time window. Then, daily streamflow indexes at SS were calculated to disaggregate annual to daily streamflow at TS through the process. The same steps are replicated to disaggregate monthly streamflow to the daily flow for the purpose of comparison between the two methods. The results are well represents daily streamflow at two methods inquiry comparing to observe data, and also maintain the time series statistical characteristics and mass equilibrium. The comparative results suggest that the monthly to daily disaggregation method perform better than annual to the daily disaggregation method. The daily streamflow generated in this study can be used in the future research for water resources planning and management.