不同时间尺度的中长期水文预报研究

为研究中长期水文预报时间尺度对预报精度的影响,选取最近邻抽样回归模型与基于小波分析的组合模型对长江干流典型断面不同时间尺度的径流序列进行中长期径流预报。将1980~2012年的逐日径流资料经过时间聚集方法转换成三天、周、旬、半月、月、双月、季、半年、九月、年等10个不同时间尺度,对高场、寸滩、宜昌、螺山、汉口、大通6个典型断面的径流进行拟合和预报。结果表明:随着预报时间尺度增加,预报精度呈现先降低后提高的趋势,其中,在月时间尺度上预报效果最差,三天和年尺度上预报效果相对较好。

Time-scale Features of Medium- and Long-range Hydrological Forecasting

In order to study the influence of hydrological time-scale on the forecasting accuracy of medium- and long-range hydrological forecasting, the nearest neighbor bootstrapping regressive model and combination model based on wavelet analysis were used to forecast runoff series of different time scales in the Yangtze River Basin. The daily runoff series of Gaochang, Cuntan, Yichang, Luoshan, Hankou and Datong (the 6 key sections of the Yangtze River) from 1980 to 2012 were converted into ten time scales as three days, week, ten days, half month, monthly, bimonthly, quarterly, half a year, nine months and yearly, and used by two models to simulate and forecast. The results show that with the increase of the forecasting time scale, forecast accuracy tends to decrease first and then increase.