ENGINEERING

Comparison of flood inundation simulation between one- and two-dimensional numerical models for an emergency action plan of agricultural reservoirs

Jae Young Kim1   Sung Ho Jung2   Min Ho Yeon2   Gi Ha Lee2   Dae Eop Lee3,*   

1Sangju Branch Office of Korea Rural Community Corporation, Sangju 37224, Korea
2Department of Advanced of Science and Technology Convergence, Kyungpook National University, Sangju 37224, Korea
3Department of Disaster Prevention KNU Emergency management Institute, Sangju 37224, Korea

Abstract

The frequency of typhoons and torrential rainfalls has increased due to climate change, and the concurrent risk of breakage of dams and reservoirs has increased due to structural aging. To cope with the risk of dam breakage, a more accurate emergency action plan (EAP) must be established, and more advanced technology must be developed for the prediction of flooding. Hence, the present study proposes a method for establishing a more effective EAP by performing flood and inundation analyses using one- and two-dimensional models. The probable maximum flood (PMF) under the condition of probable maximum precipitation (PMP) was calculated for the target area, namely the Gyeong-cheon reservoir watershed. The breakage scenario of the Gyeong-cheon reservoir was then built up, and breakage simulations were conducted using the dam-break flood forecasting (DAMBRK) model. The results of the outflow analysis at the main locations were used as the basis for the one-dimensional (1D) and two-dimensional (2D) flood inundation analyses using the watershed modeling system (WMS) and the FLUvial Modeling ENgine (FLUMEN), respectively. The maximum inundation area between the Daehari-cheon confluence and the Naeseong-cheon location was compared for each model. The 1D flood inundation analysis gave an area of 21.3 km2, and the 2D flood inundation analysis gave an area of 21.9 km2. Although these results indicate an insignificant difference of 0.6 km2 in the inundation area between the two models, it should be noted that one of the main locations (namely, the Yonggung-myeon Administrative and Welfare Center) was not inundated in the 1D (WMS) model but inundated in the 2D (FLUMEN) model.

Figures & Tables

Fig. 1. Study basin.