Testing the impacts of wildfire on hydrological and sediment response using the OpenLISEM model. Part 1: Calibration and evaluation for a burned Mediterranean forest catchment

Abstract Models are typically applied to estimate the potential adverse effects of fire on land degradation and water resources and the potential benefits of post-wildfire rehabilitation treatments. However, few modeling studies have been conducted for meso-scale catchments, and only a fraction of these studies include transport and deposition of eroded material within the catchment or represent spatial erosion patterns. This study presents an application and evaluation of the OpenLISEM physically-based and spatially-distributed hydrological and soil erosion model for a burned Mediterranean meso-scale catchment (18.5 km2) in a data-scarce environment, using a robust parameterization and calibration procedure: (1) integrating satellite imagery and the topographic wetness index to support model parameterization; (2) event-based automated calibration using the Model-Independent Parameter Estimation and Uncertainty Analysis and parameters ensemble for before and after the fire; (3) a jack-knife cross-validation for model evaluation. The study shows that this procedure used in OpenLISEM provides reasonable results for pre- and post-wildfire catchment discharge and sediment transport (r2 and NSE > 0.5; absolute PBIAS