The Round Robin Test on Landslide Hydrological Modeling at IWL2013

During the Third Italian Workshop on Landslide, a special session was dedicated to a landslide hydrological modeling competition. The modeling exercise dealt with slopes covered with loose granular pyroclastic deposits typical of Campania (southern Italy). The data provided to the participants for the calibration of their models are described, consisting of: soil physical characterization experiments carried out over small soil specimens; controlled infiltration experiments in small scale slope physical models; field monitoring. After model calibration, the participants were asked to provide blind predictions of the following experiments: controlled infiltration in a physical model of a slope reconstituted in a laboratory flume, lasting until the failure of the slope; measured rainfall infiltrating in a monitored field site. The results obtained by the participants using very different models show that complex coupled physically-based models, requiring large sets of data for their calibration, allow to shed light upon the hydrological processes leading to landslide triggering, while simpler models, easier to calibrate, may be preferred when only the major macroscopic aspects of the phenomena, such as approximate time and location of the failure, are needed.