基于FREAD溃坝体系的堰塞湖溃决过程反演分析

FREAD's dam-break system-based backanalysis on failure process of landslide dam

为了提出适用于堰塞湖溃决模拟仿真的方法,在系统梳理FREAD溃坝洪水分析体系DWOPER、DAMBRK、BREACH和FLDWAV模型的基础上,对各模型的基本原理、适用条件及优缺点进行了汇总。基于各模型的功能特点,联合使用BREACH溃坝计算模型及FLDWAV洪水演进模型反演了尼泊尔逊克西(Sunkoshi)堰塞坝的溃决过程。结果表明:逊克西堰塞坝溃决过程历时68 min达到溃决洪峰流量1 794 m3/s,考虑到支流入流的情况,溃决洪峰历时154 min演进至下游37.9 km处的库帕瓦加特(Pachuwarghat)水文站,计算流量结果与该水文站实测数据较为一致,从而验证了联合使用BREACH和FLDWAV模型进行堰塞湖溃决计算的合理性和可行性。研究成果可以为制定类似堰塞湖溃决的应急处置方案提供参考。

In order to propose a method suitable for the simulation of failure of landslide dam, the DWOPER, DAMBRK, BREACH and FLDWAV models in FREAD＇s dam-break flood analysis system are systematically sorted out for summarizing the basic principles, adaptable conditions, merits and defects of all of them. Based on the function characteristics of all the models, a back analysis is made on the failure process of Sunkoshi Landslide Darn with the joint-utilization of both BREACH model for dam-break and FLDWAV model for flood routing. The result shows that the failure process of Sunkoshi Landslide Dam reaches the dam failure flood peak discharge of 1 794 m3/s through a duration of 68 min, while the duration for the routing of the dam failure flood peak discharge to Pachuwarghat Hydrological Station that is 37. 9 km downstream from the breach is 154 min under the consideration of the tributary inflows, from which the calculated discharge result is relatively coincided with the measured da- ta from the hydrological station, thus the feasibility and reasonability of the calculation made on the failure of landslide dam with the joint-utilization of both BREACH model and FLDWAV model are verified. The study result can provide references for making the emergency treatment scheme for the similar landslide dam.