İmranlı baraj yıkılmasının 2B modellenmesi ve taşkın yayılımının farklı uzaktan algılama ürünü geometrik veriler kullanılarak karşılaştırılması

The consequences of a dam break flood in the downstream region could be analyzed by 2-dimensional (2D) unsteady hydrodynamic models which can simulate the flow in two directions by accounting for St. Venant's or diffusion wave equations. They necessitate detailed geometric data of the study region, land cover data and dam break hydrograph. This study assesses the effects of different remote sensing geometric data in a 2D hydrodynamic flood modeling via HEC-RAS.v6. The methodology is applied to İmranlı town in Türkiye since there is a dam located upstream. The breach hydrograph is modeled with an overtopping scenario by assuming a flood having 500 years return period breaks the dam when the dam reservoir lake is full. Manning roughness values are determined using the satellite product of the ESA-WorldCover land use map. The model is tested using two Digital Surface Models (DSMs) and two Digital Elevation Models (DEMs) data: LIDAR DSM, HGM DSM, ALOS-PALSAR DEM, and SRTM DEM. High resolution LIDAR data has been used by mosaicking with other data sets since it is only available for the urbanized region. Thus, the study also assesses the effects of merging high-resolution and low-resolution data. The results are compared using Mean Absolute Error (MAE), Root Mean Square Error (RMSE), F-index, and the correlation coefficient (R2). The comparisons are also conducted with different maps (flood inundation area, water depth, velocity, duration, and hazard).