Author(s): Matteo Ventura, Fabrizio Cabas, Giovanni Costantini, Chiara Cesali
Linked Author(s): Matteo Ventura
Keywords: Kingdom of Saudi Arabia, hydrologic analysis, peak discharge, arid zones hydrology.
Abstract: The lack of hydrological data records, and in particular of discharge measurements, represents, in the arid and semi-arid regions, a critical aspect that many authors, engineering firms and organizations have faced in the last few years, in order to define reliable methods and equations for the estimation of the peak discharge from drainage basins, applicable to infrastructures, flood defense and groundwater management projects. The present article shows the main results of a study conducted during the design of The Saudi Landbridge Railway Project (client: S. A. R. ) for an elevated number of watersheds in the Central Regions of the Kingdom of Saudi Arabia. In these areas, the only available rainfall data with acceptable time interval of records and an adequate spatial distribution, are the daily cumulative rainfall depths. Suitable peak discharge estimation methodologies with this type of data were investigated; particularly, three different methods for the Peak Discharge Estimation related to a Return Period of 1 in 100 year ARI (Average Recurrence Interval) were considered: Regression Equation (Saudi Ministry of Transportation), Talbot Equation, and HEC-HMS software (using SCS method). Since it is the only method that takes into account both the actual rainfall phenomenon and the ground features through the so-called Curve Number (CN), HEC-HMS method has been considered as a base reference in comparison with the other methods. The suitability of this method for the territory of the KSA has been verified through a calibration analysis, using available local information and existing studies. The comparison between the different methodologies, for different drainage basin dimensions and for different locations within the area of study, showed that the Talbot and the Regression Equations are affected by a considerable error in the estimation of peak discharge; conversely, the HEC-HMS method provides reliable estimations of the Peak Discharge for engineering purposes in these zones
Year: 2017