Research on the Optimal Identification of Thermal Diffusivity of Fresh Ice in Reservoirs of Cold Regions

The series data of atmospheric temperature, total radiation on fresh ice surface, ice temperature, ice thickness, fresh water temperature and so on, are obtained in Hongqipao reservoir, Heilongjiang Province during December 2008-March 2009 and November 2009-Aprirl 2010. Based on the data of ice temperature, nonlinear relationship of fresh ice thermal diffusivity dependent on ice temperature is identified by using the method of parameter identification of distributed parameter system. The change of ice temperature in second reservoir of Fen-river, in the city of Taiyuan, Shanxi Province in the vertical direction is simulated from 00:00 23rd January to 24:00 30th January in the year of 2004 by applying the identified relationship in the study. The comparison of the calculated and the observed ice temperature shows that the relationship between thermal diffusivity of reservoir fresh ice and ice temperature is effective.