La planicie costera de Ajó en la Provincia de Buenos Aires conforma un humedal cuyas características hidrológicas se diferencian según se trate de sectores de marisma influenciados por los flujos mareales o que se encuentren fuera del ciclo mareal. El objetivo del trabajo es evaluar el rol de la evapotranspiración en el funcionamiento geohidrológico del sector del humedal que se sitúa fuera del ciclo mareal. Para tal fin se analizaron imágenes satelitales Landsat visible-infrarrojo cercano (VNIR), datos de precipitaciones, de temperatura y de niveles y química (iones mayoritarios e isótopos) del agua superficial y subterránea entre septiembre de 2005 y marzo de 2006, abarcando un periodo húmedo y uno seco. Los resultados muestran que en la transición del periodo húmedo al seco se produce una disminución del área inundada, un descenso de los niveles freáticos y un aumento en la salinidad y contenido iónico del agua superficial y subterránea. Los balances hídricos y el contenido en cloruros e isótopos muestran la relevancia de la evapotranspiración que se encuentra evidenciada en la dinámica y calidad del agua del humedal.
The wetland of the Ajó coastal plain in the Province of Buenos Aires shows different hydrological characteristics depending on whether the sector is influenced by the tidal flow or not. The aim of this work is to assess the role of evapotranspiration in the geohydrological behaviour of the sector of the wetland which remains out of the tidal cycle. Landsat visible and infrared (VNIR) satellite images, rainfall, temperature, chemical data (major ions and isotopes) and water level of surface and groundwater were analysed. The study includes a wet and a dry period between September 2005 and March 2006. A decrease in the flooded area, a deepening of the water table and an increase in the salinity of the surface water and groundwater were observed in the transition of the wet period to the dry period. The water budgets and the chloride and isotope contents indicate the relevance of evapotranspiration, which is demonstrated by the hydrodynamic and hydrochemical conditions of the wetland.
El rol de la evapotranspiración en la geohidrología del humedal de la Planicie Costera de Ajó (Provincia de Buenos Aires)
Braga F;Tosi L
2013
Abstract
The wetland of the Ajó coastal plain in the Province of Buenos Aires shows different hydrological characteristics depending on whether the sector is influenced by the tidal flow or not. The aim of this work is to assess the role of evapotranspiration in the geohydrological behaviour of the sector of the wetland which remains out of the tidal cycle. Landsat visible and infrared (VNIR) satellite images, rainfall, temperature, chemical data (major ions and isotopes) and water level of surface and groundwater were analysed. The study includes a wet and a dry period between September 2005 and March 2006. A decrease in the flooded area, a deepening of the water table and an increase in the salinity of the surface water and groundwater were observed in the transition of the wet period to the dry period. The water budgets and the chloride and isotope contents indicate the relevance of evapotranspiration, which is demonstrated by the hydrodynamic and hydrochemical conditions of the wetland.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
