Description
Summary:Development of a hydrologic model of the Chena River Watershed located in central Alaska is described. The flow in the Chena River is controlled by the Moose Creek Dam project upstream of Fairbanks, AK. The Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) hydrologic model is intended to estimate inflows into the Moose Creek Dam Project and determine the Probable Maximum Flood (PMF) hydrograph. The Chena River watershed covers 2115 mi(expn 2). It is characterized by extensive snowmelt in spring and heavy precipitation events in summer. The Chena River is typically in continuous recession from October through April because of the subfreezing air temperatures. Permafrost areas were estimated using a GIS based binary Logistic Regression model. Monthly values for evapotranspiration and the air temperature lapse rate were estimated using the available data. A temperature index snow model was developed and calibrated with existing snow water equivalent data. The HEC-HMS model was calibrated based on 3 years of continuous simulation between 1 April and 31 August. Both large snowmelt and precipitation events were simulated. The model was verified for an additional 3-year period. All the HEC-HMS model parameters are listed in the report. The PMF hydrograph was estimated. The original document contains color images.