衡水湖湖面蒸发模拟在水位预测中的应用

精确的预测湖面蒸发是衡水湖水位预测的关键性问题。2018?2020年开展现场实验，采用水量平衡法测定了衡水湖水面蒸发过程，基于能量平衡和蒸发动力学过程，考虑了湖面植物覆盖区及水面区蒸发面阻力和空气动力学阻力对蒸发过程的影响机理，建立了衡水湖水面蒸发动力学模型。基于Sobol全局性敏感分析方法分析了气象因子、空气动力学因子和湖面因素对湖面蒸发的敏感性。结果表明：所提出的模型具有较高的计算精度，参数率定期和验证期湖面蒸发量的纳什效率系数（NSE）分别为0.744和0.687，模型中辐射项和空气动力学项对衡水湖湖面蒸发的贡献率分别为45.6%～76.8%、23.2%～54.4%。模型有效的反映了植物覆盖区和水面区的阻力对蒸发过程的影响。影响湖面蒸发的因子中，气象因子的一阶敏感性指数均值为0.118，显著的高于阻力（空气动力学阻力和水面阻力）的一阶敏感指数均值（0.028），辐射、大气温度与其他因素之间交互影响的敏感性最为显著，所提出的衡水湖蒸发量计算方法满足衡水湖水位预警和生态预报的精度要求，具有较高的精度。

Application of lake evaporation simulation method in the water level prediction of Hengshui Lake

Accurate simulation of lake evaporation plays a key role in the prediction of the water level of Hengshui Lake.The evaporation of the Hengshui Lake was measured using water balance method from 2018 to 2020.A physical based model was developed to simulate lake exploration, in which the surface resistances and aerodynamic resistances of the water surface and the aquatic plants were used to describe the water vapor diffusion processes. The sensitivity of the meteorology, aerodynamic resistances, and lake surface resistance to the evaporation was analyzed using the Sobol method. Results showed that the Hengshui Lake evaporation was accurately simulated using the proposal model. The N-S efficiency coefficients were 0.744 and 0.687, respectively in the model parameters calibration and model verification stages. The contribution ratios of the radiation and the aerodynamic term to lake evaporation was 45.6% to 76.8%, and 23.2% to 54.4%, respectively. The first-order sensitivity Sobol index of the meteorology was 0.118, significantly higher than the mean of the sensitivity Sobol index of the resistances(0.028). The developed model can be used in the water level prediction of thehengshui lake for the early warning and ecological purpose.