HEC-HMS分布式水文模型的时间尺度效应研究

Effects of Time Step of HEC-HMS on Hydrological Processes Modeling

运用分布式水文模型HEC-HMS,以福建省晋江西溪流域为例,建立该区域次降雨径流模型.采用多时间尺度检验的方法,探讨不同模拟步长对模拟结果的影响.结果表明,随着模拟步长的增加,单位步长内的降雨强度发生了明显的变化,导致模拟的洪峰流量及洪量减小,峰现时间延迟,1h时间步长模拟的洪峰流量为3188.5 m3/s,12 h时间步长模拟的洪峰流量则减少到1 560.2 m3/s,洪量(径流深)从107.79 mm减少到90.42 mm,峰现时间延迟了12 h,在实际应用中应注意选择合适的时间步长.

In this study, a spatially distributed hydrologic model, HEC-HMS, was examined for its applicability in the Xixi watershed, a 2 459 km^2 drainage basin in southeast China. The model was applied to explore the effects of time tep on model performance by using the method of multi-resolution validation. The results showed that, with the increase f time step from lh to 12 h,peak flow was simulated as 3 188.5 m^3/s to 1 560.2 m^3/s resulting from the reduction of rainfall intensity,volumes was simulated as 107.79 mm to 90.42 mm,and the time to peak was delayed 12 h.