雪覆盖下冰盖的热力增厚和消融

雪覆盖下冰盖的热力增厚和消融是急需研究的问题,对于冬季降雪频繁地区开河预报、冰凌洪水风险分析具有重要的实用价值。基于雪盖和冰盖的热力条件是准稳态假设,建立了冰盖热力增厚和消融速率与雪厚、冰厚、大气传递给雪面的净热通量和水体传递给冰底面净热通量的函数关系,包括：太阳辐射、反射和透射,雪面和大气的长波辐射,雪面蒸发-对流,河床地温等因素。提出了雪面温度和冰盖垂向温度分布的理论公式及冰盖热力增厚和消融发展过程的数值计算模型。最后,以黑龙江漠河段实测的冰情为例,验证了所提冰盖热力增厚和消融数学模型的实用性,并分析了一些重要参数随时间的变化特点。

Thermal growth and decay of ice cover under snow cover

The thermal growth and decay of ice cover under snow cover is an urgent research problem,which has important practical value for break-up date prediction and ice flood risk analysis in areas with frequent snowfall in winter.Based on the assumption that the thermal conditions of the snow cover and the ice cover are quasi steady state,the functional relationships among the thermal growth and decay rates of the ice cover,the snow cover thickness,the ice thickness,the net heat flux transmitted by the atmosphere to the snow surface and the net heat flux transmitted by the water body to the bottom of the ice cover are established,including solar radiation,reflection and transmission,long wave radiations of the snow surface and the atmosphere,evaporation-convection of the snow surface,ground temperature of the riverbed and other factors.The theoretical formulas of snow surface temperature and ice cover vertical temperature distribution and the numerical calculation model of ice cover thermal growth and decay development process are proposed.Finally,taking the ice conditions measured in the Mohe section of the Heilongjiang River as an example,the practicability of the proposed mathematical model for the thermal growth and decay of the ice cover is verified,and the variation characteristics of several important parameters with time are analyzed.