Occurrence of emergencies and disaster analysis according to precipitation amount

An analysis of the occurrences of events related to precipitation, considering extensive and intensive risk, i.e., emergencies and disasters, based on twenty-nine years of data for five cities of Ecuador provided relevant information about the behavior over time of floods, river overflows and landslides. The records of events were examined in the immediate and in the short term, which corresponded to 5 and 30 days, respectively, using the data mining methods k-means and association rules, to identify the patterns that govern their behaviors with respect to the observed amount of precipitation. The results show an increase in the frequency of similar events, with the occurrences being separated by shorter periods in recent decades. The behavior of emergencies and disasters indicates that emergencies are expected for periods of 5 days, with low quantities of precipitation and for periods of 30 days with normal quantities of precipitation. Disasters are expected, for both periods of 5 and 30 days, in the higher quantiles of precipitation. Interrelations between floods, river overflows and landslides were identified in all cities, with at least one relationship between two of the hazards for each city. An apparent flood–river overflow–landslide cycle could explain the mechanics of their occurrence. The information provided by the results indicates the vulnerability of the cities over time, their low capacity to support normal quantities of precipitation and their high exposure to hydro-meteorological hazards. The products obtained could be used together with precipitation prediction to anticipate possible effects and to formulate adequate risk management policies.