Unlocking watershed mysteries: Innovative regionalization of hydrological model parameters in data-scarce regions

作     者：Mihret, Temesgen T. Zemale, Fasikaw A. Worqlul, Abeyou W. Ayalew, Ayenew D. Fohrer, Nicola 

作者机构：Bahir Dar Univ Fac Civil & Water Resources Engn Bahir Dar Ethiopia Assosa Univ Dept Water Resources & Irrigat Engn Assosa Ethiopia Int Ctr Agr Res Dry Areas ICARDA Tunis Tunisia Univ Kiel Inst Nat Resource Conservat Dept Hydrol & Water Resources Management Kiel Germany 

出 版 物：《JOURNAL OF HYDROLOGY-REGIONAL STUDIES》 (J. Hydrol. Reg. Stud.)

年 卷 期：2025年第57卷

核心收录：

基　　金：Ethiopian Ministry of Water and Energy and Ethiopian Meteorological Institute 

主　　题：Upper Blue Nile River Basin Hydrological modeling GR4J Regionalization Regression equation Ungauged watersheds Grid-based modeling Streamflow prediction 

摘      要：Study region: The Upper Blue Nile Basin in Ethiopia, characterized by its complex hydrological system, is the focus of this study. The basin includes 76 gauged watersheds, which were analyzed to estimate parameters for ungauged locations using regionalization techniques. Study focus: Regression-Based Approach (RBA), Physical Similarity Approach (PSA), and Spatial Proximity Approach (SPA), for estimating GR4J model parameters. A 25 km by 25 km fishnetbased grid was implemented to enable parameter prediction for ungauged watersheds. Principal Component Analysis (PCA) and k-means clustering were used to group gauged watersheds into three homogeneous clusters, with Beressa, Dedessa, and Gilgel Abay selected as pseudowatersheds for validation. Model performance was evaluated using PBIAS, R2, and NSE metrics. New hydrological insights for the region: The RBA outperformed PSA and SPA in parameter transfer, achieving R2 values of 0.57, 0.79, and 0.67;PBIAS values of 7.3, -1.5, and 2.6;and NSE values of 0.58, 0.78, and 0.67 for Beressa, Dedessa, and Gilgel Abay, respectively. Incorporating grid-based parameter values further improved model performance, with NSE values of 0.81 for Dedessa, 0.63 for Beressa, and 0.61 for Gilgel Abay. These findings highlight the effectiveness of the grid-based regionalization approach for accurate streamflow prediction in ungauged watersheds within the Upper Blue Nile Basin.