基于水热平衡的融雪过程研究

The Study on Snowmelt Processes Based on Energy and Water Balance Theory

融雪过程作为一种特殊的水文现象,其复杂的物理过程以及融雪过程的不确定性是模拟的重点和难点.在研究区多年融雪过程观测实验基础上,运用数值模拟方法,构建了基于能量平衡的单点双层融雪模型,对2010年研究区点尺度的融雪期的能量项和融雪水量进行了模拟.模型较好地模拟了融雪期水热过程变化情况,模拟结果与实测值较为符合.结果表明:气温是决定融雪速率的主要因素,当气温急剧上升时容易发生融雪性洪水,而气温缓慢上升,大量融雪水变为土壤水或者壤中流,不易发生大的洪水.

As a special hydrological phenomenon, the snowmelt processes has complex physics courses and uncertainty, which are the emphasis and difficulties during modeling the snowmelt processes. This paper is account for the requirement of snowmelt flood forecasting, aiming at the keystone and difficulty during the snowmelt process modeling, using the field observation experiments and computer numerical simulative methods to establish a double-layer snowmelt model that bases on energy balance theory, and simulated the energy and water balances during snowmelt period in 2010.The water and heat processes are simulated consistently by the model ,the results are also consistent with the measured values.It is indicated that solar radiation is the primary energy fountainhead, and the air temperature is major cause that decides the snowmelt speed, when the air temperature increased repaidly it will easily snowmelt flood, otherwise large number of snowmelt water out of snow pack will transform into soil water and underflow, and it is hardly to form large flood.