IAHS2022-75, updated on 22 Sep 2022
https://doi.org/10.5194/iahs2022-75
IAHS-AISH Scientific Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

A comparative assessment of event based and continuous rainfall runoff modeling for small and ungauged watersheds in Upper Blue Nile Basin, Ethiopia

Dessalegn Worku Ayalew1, Andrea Petroselli2, Davide Luciano De Luca3, Ciro Apollonio4, and Salvatore Grimaldi5
Dessalegn Worku Ayalew et al.
  • 1Department of Soil Resources and Watershed Management, College of Agriculture, Woldia University, Woldia, Ethiopia (desuworku60@gmail.com)
  • 2Department of Economics, Engineering, Society and Business Organization (DEIM), University of Tuscia, Viterbo, Italy (petro@unitus.it)
  • 3Department of Informatics, Modelling, Electronics and System Engineering, University of Calabria, Arcavacata di Rende (CS), Italy (davide.deluca@unical.it)
  • 4Department of Agriculture, Forests, Nature and Energy (DAFNE), University of Tuscia, Viterbo, Italy (ciro.apollonio@unitus.it)
  • 5Department for Innovation in Biological, Agro-food and Forest Systems (DIBAF), University of Tuscia, Viterbo, Italy (salvatore.grimaldi@unitus.it)

Ethiopia is characterized by observed rainfall and runoff data scarcity and consequently, still nowadays the rational formula is commonly applied for estimating the design peak discharge.

In this contribution we would like to verify if more advanced hydrological tools can be applied in such challenging conditions and we provide a comparative assessment of event based and continuous modeling approaches in estimating the design hydrographs for small and ungauged basins.

The event based approach is applied using the freeware software named EBA4SUB. It is a classical approach, specifically tailored for ungauged conditions, that consists in selecting a design rainfall event based on the Depth-Duration-Frequency (DDF) curves’ parameters, estimating the rainfall excess, and transforming it into the direct hydrograph. The continuous approach is applied using the freeware software named STORAGE and COSMO4SUB. STORAGE is designed for generating long and high resolution synthetic rainfall timeseries based on scarce raingauge observations, like daily rainfall amount and DDF parameters, while COSMO4SUB is the continuous rainfall–runoff module.

Results seem promising, in particular we verified that the Ethiopian small and ungauged watersheds can be modeled using advanced approaches that offer more complete design information for the practitioner as respect to the rational formula.

How to cite: Ayalew, D. W., Petroselli, A., De Luca, D. L., Apollonio, C., and Grimaldi, S.: A comparative assessment of event based and continuous rainfall runoff modeling for small and ungauged watersheds in Upper Blue Nile Basin, Ethiopia, IAHS-AISH Scientific Assembly 2022, Montpellier, France, 29 May–3 Jun 2022, IAHS2022-75, https://doi.org/10.5194/iahs2022-75, 2022.