基于二维水动力模型的溃坝洪水模拟研究OA

In view of the abrupt onset and high destructive power of floods following dam failure,clarifying the propagation and inundation patterns of dam-break floods is an important basis for disaster prevention and mitigation and for formulating emergency evacuation plans.Taking the Huoshishan Reservoir in Biyang County,Zhumadian City,Henan Province,as the study object,a GPU-accelerated two-dimensional hydrodynamic model was constructed and coupled with a gradual dam-break calculation model to simulate the progressive expansion of the breach.The dam-break outflow was superimposed on the spillway discharge to form the inflow boundary.Three scenarios—the design flood,the check flood,and the flood exceeding the dam crest elevation—were selected to simulate the routing of dam-break floods in the downstream plain area,and the inundation extent,water depth distribution,and flood-peak propagation characteristics were quantitatively analyzed.The results show that under the scenario of the flood exceeding the dam crest elevation,the dam-break flood exhibits a pattern of"rapid rise—single peak—gradual recession",and the inundation depth undergoes a dynamic evolution of"shallow-water overbank spreading—increasing water depth—deep-water dominance—slow recession of shallow water".The spillway pre-release and the gradual breaching mode of the earth-rockfill dam can reduce the dam-break flood peak.As the flood propagates downstream,the onset of rise and peak occurrence are successively delayed,the peak attenuates along the routing path,and the inundation duration shortens.Jiuligang Village in Chunshui Town,located closest to the dam,experiences the greatest inundation depth and the longest inundation duration,and thus has the highest risk.As the upstream inflow condition escalates from the design flood to the flood exceeding the dam crest,the downstream inundation area increases from 2.86 to 7.76 km2,the maximum inundation depth rises from 6.67 to 10.65 m,and the proportion of deep-water areas with water depths greater than 3.0 m increases from 6.3%to 30.9%,indicating progressively increasing hazard severity.