Document Type : Research Paper

Authors

• Saeed Jahanbakhshasl ¹
• Majid Rezaeebanafsheh ¹
• Masood Godarzy ²
• Abdolmohammad Ghaforyrozbehany ³
• MohammadHossein Mahdiyan ³

¹ Tabriz University Department of Geography

² Tabriz University and Research Centre scarcity and droughts faculty member

³ Research scarcity and drought

Abstract

One of the main objectives in hydrology is rainfall–runoff forecasting systems for determination of flood hydrograph in outlet of a watershed. Flood discharge could be estimated using rainfall-runoff models, which explain hydrological phenomena for un-gauged watersheds. The aim of this study was to investigate the consistency, accuracy and reliability of time–area and Clark Instantaneous unit hydrograph models in estimating the shape, peak discharge, time to peak, time base and volume hydrograph of flood resulting from a rainfall with certain intensity and duration. For this purpose the topographic map of Bazoft watershed digitized by using R2V package, the digital elevation model (DEM) and isochronal prepared with the ILWIS software. Finally, the flood hydrographs were estimated by Clark and Time-Aria models for six selected storm events. The computed hydrographs then compared with those obtained by measured data. The results show that the Clark model gives a better estimation of outlet hydrograph in comparison with time-area model.

Keywords

• Instantaneous Unit Hydrograph
• Clark Model
• Time-Area Model
• Flood Estimating