Hydrological Modeling and Evaluation of the Efficiency of Culverts in Drainage Basins Affecting the North Railway in Wadi Malham

Abstract

The North Railway is one of the longest railway lines in the world, extending for 2750 km from the Riyadh region to Al-Jawf Province through many diverse topographies, including valleys where direct runoff is generated that cross the existing hydraulic protection installations on the railtrack. Direct runoff flows in quantities that exceed the capacity of existing drainage installations and cause several types of damage, owing to the nature of the drainage basins and the impact of changing natural factors and human errors. To ensure the safety of the design of hydraulic drainage installations, this indicates the need for hydrological studies of drainage basins, especially those that include important strategic facilities such as railway lines. In this study, the hydrological modeling of four subdrainage basins (No. 6, 7, 13, and 14) within Wadi Malham was applied and evaluated to determine if the drainage installations can accommodate the direct peak runoff flow. According to the results, the peak flows of 8.9 m3/s for basin No. 7 and 18.2 m3/s for basin No. 13 indicate that they are unable to handle the direct peak runoff flow from the designed storm for a return period of 100 years. The other two basins are able to pass through the peak flow. Based on the findings of this study, we recommend adding an opening for culvert C0400 in basin No. 7 and adding two openings for C0244 in basin No. 13 to accommodate the peak flow.