| High latitude lakes and rivers as well as reservoirs in China north of the Qinling and Huaihe rivers as well as in the northwest and southwest freeze in winter,resulting in ice formations.The ice pressure brought by ice generation poses a serious safety threat to hydraulic buildings,but in some northern areas of China,it is found that there is a phenomenon of ice-shore disconnection in winter.The existence of this phenomenon indicates that hydraulic buildings that receive more solar radiation energy during the freezing period have a great influence on the process of ice generation and elimination,thickness,etc.,which in turn has an impact on the ice-shore connection in time and space.In order to cope with the disaster problems caused by ice pressure on the shore hydraulic structures in cold areas,this paper researches and analyzes the solar radiation characteristics in the Liaohe estuary area and the influence of solar radiation received by the shore slope on the ice layer of shore ice based on the field test observation data of Han Zhang Lake in the Liaohe estuary area during January to March 2021.During the observation period,this study compares the accuracy of each model under different sky conditions by using the solar radiation data measured in Liaohe estuary area.The analysis results show that the accuracy of Gueymard model is the highest,followed by isotropic models under overcast condition.The accuracy of Willmott model and the comprehensive performance of Reindl model is the best under cloudy condition and sunny condition respectively.The accuracy of Willmott model and Reindl model is high when the sky conditions are not distinguished.Based on the characteristics of the measured solar radiation data,the existing calculation model is rewritten,a new calculation model is established,and the measured data was used to analyze the accuracy of each model without distinguishing weather conditions.The results show that the calculation accuracy of the new model is significantly improved.Parameterized formulas for daily and hourly scattered radiation under different weather conditions in the Liahe estuary and adjacent areas in winter were established using scattered radiation fraction and clear sky index.The new model is also used to calculate the solar irradiation received per unit area of different inclined surfaces in winter in the Liaohe estuary.Based on the in situ observations of lake ice,it was found that the freezing time of shore ice relative to the center of the lake was delayed by 22 days,the ice stabilization period was advanced by 14 days,the melting period was advanced by 23 days,and the maximum ice thickness was reduced by 16.3 cm due to the influence of solar radiation received by the shore slope.After analyzing the shore water temperature and the ice temperature of the shore ice layer as well,it was found that there was an obvious linear relationship between the horizontal water temperature 10 cm below the shore water surface,and after comparing the ice temperature of different ice thicknesses with the air temperature,it was found that the lagging effect of the shore ice temperature relative to the air temperature was more obvious compared with that of the lake center ice layer.Based on the residual energy method and the HIGHTSI model,the energy transfer between the bank slope,water and ice was analyzed,the conductive heat flux from the bank slope to the water body and the water-to-ice heat flux were obtained.At the same time,the effects of different side slopes on the ice-shore connection were also analyzed using linear assumptions,and the differences in the heat fluxes conducted by the slope to the water column and the effects on the ice thickness of the shore ice were obtained under different shore slope conditions. |
PDF Full Text Request