An Innovative Approach at Calibrating Stage/Storage/Discharge Behavior in Hydrologic Modeling

Very often in calibrating surface or integrated surface and groundwater hydrologic models much time and energy is expended trying to manually derive stage/storage/discharge behavior of the stream and drainage system. Often tens or hundreds of reaches exist in a model domain with limited survey data and very few calibration stations or records. Traditional calibration using general stream cross-sections and Manning or other discharge relationships can be time consuming and uncertain due to limited calibration stations and limited x-section data. Recent insight gained about coupled generalized state/storage (Nilsson and Ross model) and stage/discharge (Mueses and Ross model) behavior using eighteen gaging stations in coastal plain environments is tested and on a model calibration of the Peace River in West-Central Florida. In this model calibration, wetlands were treated as reaches in HSPF with storage-attenuation characteristics. Steps employed to examine the observed behavior in this basin against the generalized behavior may prove useful in other applications. The model predictive ability and calibration efficiency is improved due to systematic calibration as apposed to traditional manual parameter manipulation. Uncertainty in un-calibrated station performance is also reduced. The Nash-Sutcliffe Efficiency (NSE) and correlation coefficient computed using observed and simulated daily flows was 0.90 and 0.96 for the Peace River along with good simulation at all other stations in the model domain.