Geosystemic Impacts of the Extreme Rainfall Linked to the El Ni & ntilde;o 2015/2016 Event in Northern Paran & aacute;, Brazil

The El Nino episode between September 2015 and February 2016 caused abundant rainfall in the state of Parana in southern Brazil. In this study, we map the greatest magnitude of this climatic event and the respective geosystem responses in the landscape. For this purpose, 32 precipitation series were analyzed (1981-2016). The parameter most indicative of extreme rainfall events during the El Nino period was the six-month accumulated precipitation. The return period (RP) of this parameter was calculated and spatialized using kriging. The results show that a longitudinal strip of 450 km by 140 km had rainfall with RP > 30 years, reaching maximums greater than 150 years. Surveys performed in the field, with aerial images, official sources and media news show a great diversity of effects caused by rainfall, such as road blockages, interruption of water and power supply, and erosion in urban and rural areas. It is concluded that the stability of regional geosystems was disrupted because of extreme rainfall values, so that the northwest region of Parana had less resilience compared to the north-central and Pioneer North regions, due to the differences between the lithologies and soils of these regions.

Automated summary

The El Nino event from September 2015 to February 2016 led to heavy rainfall in the state of Parana in southern Brazil. This study analyzed 32 precipitation series from 1981 to 2016 to map the magnitude of the event and its impact on the landscape. The six-month accumulated precipitation was found to be the most indicative parameter of extreme rainfall during the El Nino period. The results showed that a longitudinal strip of 450 km by 140 km experienced rainfall with a return period of over 30 years, reaching maximums exceeding 150 years. Field surveys and various sources confirmed the diverse impacts of the rainfall, including road blockages, water and power supply interruptions, and erosion in urban and rural areas. The study concluded that the regional geosystems' stability was disrupted by the extreme rainfall values, with the northwest region of Parana being less resilient compared to the north-central and Pioneer North regions due to differences in lithology and soil.