Catchment Scale Evaluation of Multiple Global Hydrological Models from ISIMIP2a over North America

A satisfactory performance of hydrological models under historical climate conditions is considered a prerequisite step in any change impact study. Despite the significant interest global modeling, few systematic evaluations (gHMs) at catchment scale have been carried out. This study investigates 4 gHMs driven by observation-based meteorological inputs simulating weekly discharges over 198 large-sized North American catchments for 1971–2010 period. The 16 discharge simulations serve as basis evaluating gHM accuracy within second phase Inter-Sectoral Impact Model Intercomparison Project (ISIMIP2a). simulated four are compared against observed and values two regional (rHMs) dataset same We discuss implications both modeling approaches well influence characteristics forcing terms model through statistical criteria visual hydrograph comparison catchment-scale studies. Overall, statistics exhibit poor agreement with observations manifest considerable bias errors seasonal flow simulations. confirm that approach, experimentally implemented ISIMIP2a, must be used caution find rHM approach to more trustworthy recommend using it studies, especially if findings intended support operational decision-making.