静动水冰厚生长消融全过程的辐射冰冻度-日法预测研究

摘要

The traditional degree-day method has two shortcomings.First,it is not capable of simulating the melting of ice cover during the decay period.Second,there is an empirical constant that is site dependent.This article proposes the radiation degree-day method for predicting the whole process of ice cover thickness development respectively under the hydrostatic and non-hydrostatic conditions based on the analysis of the mechanism of the growth and decay of ice cover thickness.This method was tested and verified by simulating the ice cover thickness development in the Shengli Reservoir and Songhua River respectively.Since without empirical parameter the proposed simulation methods has definite physical meaning and broad applicability.The study reveals that：（1） the air temperature,solar radiation and water temperature are the main factors influencing the growth and decay of ice cover.（2） the effect of water temperature on ice cover under non-hydrostatic conditions is important,but it has little effect on ice cover under the hydrostatic condition.（3） the decisive factor leading to ice cover＇s melting is the solar radiation.%冰厚计算的传统方法冰冻度-日法具有两个缺点：（1）无法实现对冰盖消融过程的模拟;（2）公式中含有经验参数,需经实测数据校核后,计算结果才较为准确。针对以上两个问题。本文在深入研究不同水流条件下冰盖生长、消融机理的基础上,提出了静水、动水冰厚预测的辐射冰冻度-日法。采用统一的公式描述冰厚生长、消融的全过程,并通过对胜利水库和松花江冰厚生消过程的计算验证了算法的正确性。计算公式中没有经验参数,物理意义明确,适用范围广;静、动水冰厚辐射冰冻度-日法揭示出：（1）冰厚的生消演变主要是气温、辐射和水温综合作用的结果;（2）静水冰厚和动水冰厚生消机理的差别在于水温对静水冰厚的影响极小,可以忽略,而对于动水冰厚则极为重要;（3）辐射是冰厚消融的根本性原因。