Synthetic Unit Hydrograph Methods: A Critical Review

Abstract

The present study critically reviews the synthetic unit hydrograph (SUH) methods available in hydrologic literature. The study reveals that the traditional methods of SUH derivation, e.g., Snyder, SCS, traditional methods like Snyder and TS methods always does not yield satisfactory results, and theier application to the practical engineering problems is tedious and combursome. On the other hand, probability distribution functions (pdfs) based SUH methods are easy to apply, easily met the UH criterion, i.e. the area under the curve is unity, and rely on a stronger mathematical base and sounder hydrologic perception. The recent pdfs used for deriving UHs in ungauged catchments, address the SUH shapes with more flexibility than the earlier pdfs proposed by Gray (1961) for SUH derivation.