Authors: Hari Dhital
Title: Investigating Scale-dependent Performance of Hydrologic Simulations Using the Hillslope-Link Model
Presentation Type: Poster
Abstract: Accurate hydrologic prediction at relevant modeling scales is essential for flood risk management and effective water resource management. In this study, we explore the effect of spatial scales at which physical processes are represented on the model parameters and simulation results using the Hillslope Link Model (HLM). This was motivated by HLM implementation within the NextGen framework, which may lead to model performance changes as HLM’s modeling scale for runoff generation needs to be altered from hillslopes to catchments in Hydrofabric (i.e., “divides”). Our experiment is based on HLM implementation at two different spatial scales with keeping the same model parameters to examine similarities and dissimilarities generated solely by spatial representation of rainfall-runoff processes. To generate soil moisture and streamflow in the Clear Creek watershed in Iowa, we drive the HLM with multiple forcing dataset (precipitation, air and soil temperature, and evapotranspiration) collected during about nine years from 2016 to 2024. We do not calibrate the HLM parameters, which were predetermined a priori, as their calibration would obscure inherent differences between simulations at the two scales. Our primary objectives are to examine the trade-offs between modeling accuracy and efficiency and thereby provide the CIROH research community with useful insights for NextGen implementation.