贺兰山东麓典型流域山洪模拟及预报预警模型构建与应用

Construction and application of fl ash fl ood simulation and forecast-early warning models in typical watersheds of eastern Helan Mountain

摘要:

为进一步对贺兰山暴雨洪水进行预报预警，基于自主研发的分布式水文模型 HHmodel 和二维水动力模型 HH2D 构建贺兰山东麓 3 个典型流域的洪水预报模型。分布式水文模型将流域划分为规则的网格单元计算产流过程，根据降雨条件和下垫面土壤状态变化自动切换产流方式，二维水动力模型基于 DEM 数据并利用三角网格对区域进行剖分，以出山口水文站的流量过程作为模型输入开展洪水淹没模拟与分析。选取 2018 年 7 月典型洪水数据，模拟暴雨洪水过程、洪峰流量和峰现时间，以及洪水出山后的漫滩过程，模型结果合理。研究成果为贺兰山东麓的洪水预报预警工作提供方法及参考案例，能够进一步为干旱半干旱地区的洪水预报预警提供参考。

Abstract:

To improve the forecasting and early warning capabilities for storm-induced floods in the Helan Mountain region，flood forecasting models for three typical watersheds on the eastern Helan Mountain slope were developed using the independently designed distributed hydrological model HHmodel and the two-dimensional hydrodynamic model HH2D. The distributed hydrological model divides watersheds into regular grid units to calculate runoff processes，dynamically switching runoff generation methods based on rainfall conditions and changes in soil states. The two-dimensional hydrodynamic model employs DEM data and triangulated grids to segment the region， using flow data from mountain pass hydrological stations as input for flood inundation simulations and analyses. The model’s results，validated against the storm flood event of July 2018，including peak discharge，peak timing， floodplain inundation，and the flooding process after the flood come out of the mountain，demonstrated accuracy and reliability. This research provides methodologies and case references for flood forecasting and early warning in the Helan Mountain region and offers insights for flood management in arid and semi-arid areas.