2 resultados para Desalination of ocean water

em Scielo Saúde Pública - SP


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Climatic changes threaten the planet. Most articles related to the subject present estimates of the disasters expected to occur, but few have proposed ways to deal with the impending menaces. One such threat is the global warming caused by the continuous increase in CO2 emissions leading to rising ocean levels due to the increasing temperatures of the polar regions. This threat is assumed to eventually cause the death of hundreds of millions of people. We propose to desalinize ocean water as a means to reduce the rise of ocean levels and to use this water for populations that need good quality potable water, precisely in the poorest regions of the planet. Technology is available in many countries to provide desalinated water at a justifiable cost considering the lives threatened both in coastal and desertified areas.

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Gravity Recovery and Climate Experiment (GRACE) mission is dedicated to measuring temporal variations of the Earth's gravity field. In this study, the Stokes coefficients made available by Groupe de Recherche en Géodésie Spatiale (GRGS) at a 10-day interval were converted into equivalent water height (EWH) for a ~4-year period in the Amazon basin (from July-2002 to May-2006). The seasonal amplitudes of EWH signal are the largest on the surface of Earth and reach ~ 1250mm at that basin's center. Error budget represents ~130 mm of EWH, including formal errors on Stokes coefficient, leakage errors (12 ~ 21 mm) and spectrum truncation (10 ~ 15 mm). Comparison between in situ river level time series measured at 233 ground-based hydrometric stations (HS) in the Amazon basin and vertically-integrated EWH derived from GRACE is carried out in this paper. Although EWH and HS measure different water bodies, in most of the cases a high correlation (up to ~80%) is detected between the HS series and EWH series at the same site. This correlation allows adjusting linear relationships between in situ and GRACE-based series for the major tributaries of the Amazon river. The regression coefficients decrease from up to down stream along the rivers reaching the theoretical value 1 at the Amazon's mouth in the Atlantic Ocean. The variation of the regression coefficients versus the distance from estuary is analysed for the largest rivers in the basin. In a second step, a classification of the proportionality between in situ and GRACE time-series is proposed.