# Rainfall events and landslides thresholds

Tools for the reconstruction of rainfall events from records of rainfall measurements, for the definition of the rainfall conditions responsible for landslides, and for the definition of rainfall thresholds for possible landslide occurrence.

## Definition of rainfall events, and rainfall events with landslides

The software implelments an algorithm for the objective definition of rainfall events, and for the quantitative measurement of the rainfall conditions that characterize a rainfall event. The algorithm systematizes the actions performed and the decisions taken by an expert investigator that defines heuristically rainfall events from a typical rainfall record and information on landslide occurrence. The code is implemented using the R open-source software for advanced statistical computing and graphics, release 2.15. (http://www.r-project.org/)

## Definition of rainfall thresholds

The tool, written for the R free software environment for statistical computing and graphics, implements a Frequentist approach to determine the intercept and the slope of the power law curve selected to represent the rainfall threshold. The method is based on a frequency analysis of the empirical rainfall conditions that have resulted in known landslides. The tool further determines the uncertainties associated to the parameters that define the threshold curve.

## CTRL-T algorithm, Calculation of Thresholds for Rainfall-induced Landslides -Tool

The CTRL-T algorithm exploits continuous rainfall measurements, and landslide information, to (1) reconstruct rainfall events; (2) select automatically the representative rain gauges; (3) identifies multiple rainfall conditions responsible for the failure in terms of D and E, modelling the antecedent rainfall; (4) attributes a probability to each rainfall condition; and (5) calculates probabilistic rainfall thresholds and their associated uncertainties. The code is implemented using the R open-source software for advanced statistical computing and graphics, release 3.3.3 (http://www.r-project.org/).