Open Journal of Modern Hydrology, 2020, 10, 105-122 https://www.scirp.org/journal/ojmh ISSN Online: 2163-0496 ISSN Print: 2163-0461 DOI: 10.4236/ojmh.2020.104007 Oct. 28, 2020 105 Open Journal of Modern Hydrology Evaluating the Performance of HEC-HMS and SWAT Hydrological Models in Simulating the Rainfall-Runoff Process for Data Scarce Region of Ethiopian Rift Valley Lake Basin Mohammedreshid A. Aliye 1,2 , Alemu O. Aga 2* , Teshale Tadesse 2 , Petros Yohannes 2 1 College of Engineering and Technology, Bule Hora University, Bule Hora, Oromia Region, Ethiopia 2 Hawasa Institute of Technology, Hawasa University, Hawasa, Ethiopia Abstract A number of physically-based and distributed watershed models have been developed to model the hydrology of the watershed. For a specific watershed, selecting the most suitable hydrological model is necessary to obtain good simulated results. In this study, two hydrologic models, Soil and Water As- sessment Tool (SWAT) and Hydrological Engineering Centre-The Hydro- logic Modeling System (HEC-HMS), were applied to predict streamflow in Katar River basin, Ethiopia. The performances of these two models were compared in order to select the right model for the study basin. Both models were calibrated and validated with stream flow data of 11 years (1990-2000) and 7 years (2001-2007) respectively. Nash-Sutcliffe Error (NSE) and Coeffi- cient of Determination (R 2 ) were used to evaluate efficiency of the models. The results of calibration and validation indicated that, for river basin Katar, both models could simulate fairly well the streamflow. SWAT gave the model performance with the R 2 > 0.78 and NSE > 0.67; and the HEC-HMS model provided the model performance with the R 2 > 0.87 and NSE > 0.73. Hence, the simulated streamflow given by the HEC-HMS model is more satisfactory than that provided by the SWAT model. Keywords HEC-HMS, SWAT, Katar River Basin, Peak Flow, Rainfall-Runoff Simulation 1. Introduction Modeling of hydrological processes, like rainfall runoff, infiltration, evapotrans- How to cite this paper: Aliye, M.A., Aga, A.O., Tadesse, T. and Yohannes, P. (2020) Evaluating the Performance of HEC-HMS and Swat Hydrological Models in Simulat- ing the Rainfall-Runoff Process for Data Scarce Region of Ethiopian Rift Valley Lake Basin. Open Journal of Modern Hydrology, 10, 105-122. https://doi.org/10.4236/ojmh.2020.104007 Received: August 4, 2020 Accepted: October 25, 2020 Published: October 28, 2020 Copyright © 2020 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access