龙角山水库入库洪水实用预报方法对比研究

A Comparative Study on Practical Forecasting Methods of Flood in Longjiaoshan Reservoir

为提高流域洪水预报精度,以山东半岛龙角山水库为例,利用25场洪水资料,选择降雨径流经验相关法和新安江模型对比分析二者的预报精度。结果表明,降雨径流经验相关法在率定期和验证期的地面径流深预报合格率分别为94.1%、87.5%,精度为甲等级别;新安江模型洪峰、峰现时间和径流深三个预报项目平均合格率在率定期、验证期分别为84.3%、83.3%,精度为乙等级别。与新安江模型相比,降雨径流经验相关法能够对洪量做出更为准确的预报,而新安江模型尽管总体预报精度偏低,但其还能对洪峰和峰现时间做出预报。在实际洪水预报作业中,可采用两种预报方法相结合的方式,取长补短,对各种水文预报要素做出更加准确的预报,从而为水库调度决策提供更有利的技术支撑。

In order to improve the accuracy of flood forecasting in the basin,taking Longjiaoshan reservoir in Shandong Peninsula as an example,the antecedent precipitation index model and Xin’anjiang model are selected to compare the prediction accuracy of the two methods by 25 flood data.The results show that the qualified rate of surface runoff depth in calibration and verification period of the antecedent precipitation index model is 94.1% and 87.5%,the accuracy is grade one;The average qualified rate of flood peak,peak occurrence time and runoff depth of Xin’anjiang model in calibration and verification period is 84.3% and 83.3%,the accuracy is grade two.Compared with the Xin’anjiang model,the antecedent precipitation index model can make more accurate prediction of flood volume.Although the overall prediction accuracy of Xin’anjiang model is low,it can also forecast the flood peak and peak time.In the actual flood forecasting operation,the combination of the two forecasting methods can be used to learn from each other to make more accurate forecast for various hydrological forecast elements,so as to provide more favorable technical support for reservoir operation decision-making.