Hydro-Geomorphologic-Based Water Budget at Event Time-Scale in A Mediterranean Headwater Catchment (Southern Italy)

The Ciciriello catchment is a 3 km(2) drainage sub-basin of the Bussento river basin, located in the southern part of the Campania Region (Southern Italy). Since 2012, this catchment has been studied using an interdisciplinary approach-geomorphological, hydrogeological, and hydrological-and a hydro-chemical monitoring system. Following previous research, the aim of this paper is to calibrate, on this catchment, the hydrologic parameters for a water budget at event time-scales using the HEC-HMS model, adopting object-based hydro-geomorphological class features. Firstly, lumped modeling was performed to calibrate the hydrologic parameters from 20 observed hydrographs at the downstream monitoring station of the Ciciriello catchment. Then, physical-based rainfall-runoff modeling was conducted using three different procedures: (1) applying the recession coefficients to each outlet with a newly defined hydro-geomorphologic index (HGmI); (2) assessing the storage coefficient for each sub-basin as a weighted mean of HGmI; and (3) using the storage coefficient associated with the largest HGmI in the sub-basin. The adopted procedures were tested using diverse goodness-of-fit indices, resulting in good performance when the object-based hydro-geomorphotypes were used for the parameter calibration. The adopted procedure can thus contribute to improvements in rainfall-runoff and water budget modeling in similar ungauged catchments in Mediterranean, hilly, and forested landscapes.