Geodetic Sea Level Control in Salvador: Analysis and Correlations

Abstract

Political, social and economic factors have motivated government officials and researchers to monitor and study the behavior of sea levels. With the rise of this level, it is estimated that in 2070 150 million people would be at risk and a wealth estimated at 35 trillion dollars threatened in the 136 largest port cities in the world. For engineering, the mean sea level is of fundamental importance in determining a country's altimetric datum. In this work were used the data collected by the Salvador Tide Gauge in the period from 2009 to 2015 with the objective not only of evaluating the temporal behavior of the mean sea level in this place, in addition to detecting and quantifying vertical movements of non-oceanic origin that tend to degrade and mask the quality of these data. Computational routines were developed in order to detect and correct inconsistencies in this series. Statistical regression methods, in addition to DFA and ρDCCA, were used to analyze the series' behavior, its persistence over time and to quantify the level of cross-correlation between the tidal gauge series and the IBGE active and passive geodesic networks. The results showed the importance in the analysis and correction of the tide gauge series for the purpose of determining the mean sea level by presenting numerical differences, but qualitatively there was no significant difference, given the universe of points analyzed. Our findings indicate that the sea level is rising and, moreover, this scenario tends to continue for a long time.