A REGIONALIZATION METHOD OF FLOW DURATION CURVE FOR ESTIMATING STREAMFLOW
IN UNGAUGED CATCHMENTSIleana TĂNASE,Cătălina PETRE
ABSTRACT. – A Regionalization Method of Flow Duration Curve for Estimating Streamflow in Ungauged Catchments. Decision making in management and engineering is often requested for catchments where hydrological data is not available, like water resources forecasting, planning and operation and for different studies on physical and biochemical process.The Flow Duration Curve (FDC) represents the relationship between the magnitude and frequency of daily (or other time interval) streamflow for a particular river basin, providing an estimation of the percentage of time a given streamflow was equaled or exceeded over a historical period. Flow duration curves are considered an important tool for characterizing hydrological regimes and flow variability.The paper presents a regionalized model for predicting flow duration curve for ungauged catchments. This model was developed using a data set of 12 gauging stations with natural regime, in Siret river basin. The regional flow duration curve is based on multiple regressions between the flow with the 80% probability of occurrence from standardized flow duration curve, the hydrological response of soil types and the climate characteristics of the basin. The statistical model for estimating the flow duration curve is important for predicting natural flow statistics at ungauged sites and for impacts assessment on artificial influences within the Romanian rivers.
Keywords: regionalization, flow duration curve, regression, Siret river basin.