Variabilidade interanual dos eventos extremos e a sua percepção pela comunidade de Santa Maria de Sirituba - PA

Abstract

The perception of extreme events by man interferes in the process of adaptation to the influence of extreme climatic variability. The perception approach constitutes an important tool for the understanding of the forms of relationship between individuals or societies with the environment in which they live. Considering the interference of extreme precipitation in socioeconomic and environmental activities and the relationship in the adaptation process, this study aimed to analyze the perception of riparian communities regarding the impacts of extreme events on their social, economic and environmental activities. The research contemplates the approach of extreme precipitating events in the Santa Maria Rio Sirituba -PA community, located in the eastern region of the Amazon. The study utilized time series of monthly precipitation, surface temperature anomaly of the Niño 3.4 region and the National Oceanic Atmospheric Administration (NOAA) North and South Atlantic basin from 01/01/1979 to 12/31/2015; and local subjective aspects through semi-structured questionnaires formulated according to the classification of Marconi and Lakatos (2003) and the proposal by Whyte (1977). The classification of extreme events was categorized by the Quantis technique and related to the El Niño Southern Oscillation (ENSO) phenomena both in its positive phase (El Niño) and in the negative phase (La Niña) and the Atlantic Dipole (ADP); the degree of perception was obtained through the method of the hierarchical analysis process. The results of the study indicated that extreme precipitation may be associated with years of ENSO events and ADP patterns, with ENSO events being characterized by the reduction and increase of rainfall in the study area; it was observed that the ADP pattern may favor or disfavor the accumulated rainfall, but its influences are related to the intensity of the ENSO phenomena. In the use of the Analytic Hierarchy Process (AHP), three levels of hierarchy were defined as level 1: Perception, that is, the objective of the hierarchy; level 2 are the decision criteria: leisure (C1), work (C2) and health (C3) and level 3 the determining factors: air temperature (A1), wind (A2), tide (A3) and rain (A4). Through the standard matrix of criteria and local average priorities it was observed that criterion C2 has the highest degree of importance with relative weight (WR) of 48.99%, then the criterion C3 with WR of 45.07% and lastly the criterion C1 with a lower degree of importance with WR of 5.94%. The Global Priority (GP) obtained indicated the alternative A4 with the highest noticeable degree of weather and climate for the rivers with GP of 37.94%, then the alternatives A3, A2 and A1, with GP of 31.41%, 22.86% and 7.79%, respectively. Finally, the results showed that the rivers have a high perception of the impacts of the extreme precipitating events on the socioeconomic and environmental activities, confirmed in the AHP technique the order of importance obtained in the GP. Thus the study is relevant in the process of elaborating adaptation strategies to extreme precipitating events.