This report presents a new approach for the prediction of surface runoff peak-discharge amounts in arid and semi-arid regions.
Such predictions are important because reliable long-term storm rainfall and corresponding run-off measurements are commonly unavailable.
This is the situation in many parts of the Kingdom.
Hence it is necessary to develop a new approach, one that will suit conditions found in Saudi Arabia, which can generate a set of suitable constants, and which depend on available, but incomplete, measurements.
The specific methodology developed in this report is referred to as the Saudi Geological Survey (SGS) approach in order to reflect work along these lines, within the Survey.
The basis of the methodology has two phases, one logical and the other empirical.
The logical phase is valid for any part of the world whether humid or arid, but the empirical phase is highly location-specific, which, in the case of this report, is the southwestern part of the Kingdom.
This report deals with rainfall characteristics and geomorphologic features in Wadi Baysh, a major wadi between Abha and Jizan, in the southwestern part of the Kingdom.
The necessary logical and empirical formulation for predicting the peak-discharge amount and the time to peak are developed with the consideration of measured regional flood discharges.
Furthermore, the unit hydrograph methodology is also presented as having application to some of the Wadi Baysh subbasins.
For this purpose, a dimensionless unit hydrograph has been obtained, which is specific to the region.
Şen, Z., 2004, The Saudi Geological Survey (SGS) hydrograph method for use in arid regions, Kingdom of Saudi Arabia: Saudi Geological Survey Technical Report SGS-TR-2004-5, 20 p., 25 figs. 4 tables.