Contribution to the Understanding of Rainfalls Occurring in Buenos Aires City (Argentina) Between 1960 and 2018

Rainfall waters in Buenos Aires city are drained directly to the Río de la Plata river, carrying along pollution from the streets. Understanding the behaviour of precipitations during the last decades is of huge importance in order to prevent increasing damages to natural ecosystems. In this work, cluster analysis was applied for seasonal rainfall data, in order to group years in conglomerates with similar distribution patterns. An increasing variability of seasonal rainfall distribution was observed. For the decade 1960–1969, 80% of the years corresponded to the same distribution pattern and the remaining 20% to another one, while for the period 2000–2018, six different patterns occurred. Also, a general increasing tendency in the average daily rainfalls was observed, tending to favour flooding. Unpredictability of rainfall occurrence and increasing precipitations should be considered as additional reasons to make efforts in reducing urban contamination and developing systems to lessen flooding.