Automatic levee detection using a high-resolution DEM-Case study in Kinu river basin, Japan

Increasing needs for real-time flood forecasting, proac-tive disaster prevention using hazard maps, and adaptation to flood risks associated with climate change require more detailed and accurate inundation information. Although river levees are an important factor in defining the extent and depth of flood water, data on the height and location of levees that can be introduced into global river models are not well developed. Therefore, in this study, an algorithm was developed to automatically determine the presence of levees when multiple river levee conditions are met from high-resolution Digital Elevation Models (DEMs). In the case study on the Kinu river, the 5-meter resolution DEM data was used to properly extract the location and height of levees including discontinuous levees, and the average error in levee height was in the range of 0.7 m. When a 10-meter, 20-meter, and 30-meter resolution DEM was used, the levee location was detected reasonably while erroneous determinations increased as the resolution became coarser, suggesting that the automatic detection method requires a resolution of at least 10-meter.