Updating A Flow Frequency Analysis With Nonstationarity In Period of Record Data

In an urbanized watershed, changes in land use and regulation of the system has resulted in a nonstationarity period of record. Therefore, the period of record data needs to be adjusted to provide a homogenous dataset for a flow frequency analysis. The evaluation of historical imagery, land use data, and reservoir information are incorporated into a calibrated rainfall-runoff and reservoir models to create a homogeneous dataset equivalent to current conditions. Then, the flow frequency analysis is conducted using Bulletin 17c and hydrologic modeling.